Balustrade

Abstract

In various embodiments, the present invention provides balustrade arrangements including a plurality of vertically-extending baluster elements arranged in series along a lateral direction, with a spac

Description

Field of the Invention The present invention relates to a balustrade. It has particular, but not necessarily exclusive, applicability to a balustrade for outdoor applications, such as for balconies. Background The present invention has been devised in particular due to the inventor’s expertise in balcony systems. However, as will be apparent from the following disclosure, the invention may be embodied in different situations where balustrading is required. Balustrades are protective and / or decorative elements incorporated into a wide range of structures, including buildings, staircases, landings, decking structures and balconies. Many different forms of balustrade are known in the art: one traditional form of balustrade comprises a plurality of balusters, usually rod-like elements, arranged along and extending from a rail, with spacing gaps or channels in between each adjacent pair of balusters which allow light through the balustrade. It is known to use balustrades around the perimeter of a balcony to reduce the risk of a person falling from said balcony. More specifically, balustrades are often designed to withstand the application of a preset amount offeree so as to prevent a person from falling through the balustrade, off the balcony, and to the ground below. The balustrade may also be used as a design feature of the balcony or building more generally, to increase aesthetic appeal. However, one outstanding problem with balustrades of the traditional form described above is that they provide little to no protection against wind. Wind is a particular problem on balconies, as the elevation of balconies above ground level can mean that people on the balcony experience higher wind speeds that they otherwise would lower down. This is especially true when the wind approaches the balcony from a sideways angle (i.e., an angle that deviates from the normal to the building surface). In these cases, the building does not provide a full cushioning effect against the wind, so that a person on the balcony experiences most of the ‘full force’ of the wind. These increased wind speeds can be uncomfortable for a person on the balcony. For example, the associated ‘wind chill’ can make it unpleasant to remain on the balcony for long periods of time, especially in colder months. Moreover, the higher wind speeds experienced on balconies may make objects on the balcony susceptible to being blown over and / or off the balcony all together, which in a best-case scenario is annoying for a person when their items are being blown around, and in a worst-case scenario creates a risk of the person being blown off the balcony themselves, or for the item blown off to strike persons on other balconies or at ground level. Conventional balustrades, (e.g., those having a plurality of balusters arranged along the length of a rail with a spacing gap between each pair of adjacent balusters) simply allow wind to pass through the spacing gaps without any restriction, so that the person on the balcony is not protected from the wind at all. On the other hand, glass or solid balustrades, in which the balustrade comprises a continuous sheet of material with no spacing gaps, do provide some protection against wind incident on the balustrade. However, the use of such balustrades may give rise to alternative problems, as the solid barrier can induce eddy currents on the balcony as the wind moves around and over the top of the balustrade, such that the person on the balcony still experiences an uncomfortable level of wind. The present invention has been devised in light of the above considerations. Summary of the Invention The present inventors have realised that there exists a need for balustrades that are adapted to provide improved air flow characteristics on a downstream side of the balustrade, downstream being defined with respect to the direction of flow of an incident air stream. In the context of balustrades for use on balconies, improved airflow characteristics may include e.g. a reduction in the wind speed felt by a person on a balcony at one or more locations on the balcony, or a redirection of the air flow to direct the wind to a predetermined location on the balcony. Accordingly, at its broadest, the present invention relates to a balustrade that is adapted to cause a change in at least one air flow characteristic on a downstream side of the balustrade compared with the air flow on an upstream side of the balustrade. Air flow characteristics may include an air flow speed, and / or an air flow direction. The present inventors have realised that by adapting the cross-sectional shape of one or more baluster elements of the balustrade, such changes in airflow characteristic(s) can be achieved. According to a first aspect of the present invention, there is provided a balustrade arrangement comprising: a plurality of vertically-extending baluster elements arranged in series along a lateral direction, with a spacing gap being defined between each pair of adjacent baluster elements in the series for allowing an air flow incident on the balustrade arrangement to pass through the balustrade arrangement from an upstream side to a downstream side, wherein one or more of the baluster elements in the series have a cross-sectional shape that is selected from: a T-shape, a V-shape, a C-shape, an S-shape, a Z-shape, and trapezium shape (which may also be referred to as an ‘A-shape’). The cross-sectional shape of the baluster elements is the cross-section in plane taken perpendicular to the vertical extension direction of the baluster elements. The inventors have found that by selecting the cross-sectional shape of one or more of the baluster elements in the balustrade arrangement to be at least one of a T-shape, a V-shape, a C-shape, an S-shape, a Z-shape, and a trapezium shape (‘A-shape'), at least one characteristic of the air flow in a region on the downstream side of the balustrade arrangement can be suitably modified to provide an improved air flow profile downstream of the balustrade arrangement. More particularly, it has been found by the inventors that such a modification to one or more of the baluster elements can allow at least one of the air flow characteristics of air flow speed and air flow direction to be advantageously modified in the downstream air flow that has passed through the balustrade, such that the air flow profile on the downstream side of the balustrade is improved compared with the air flow profile on the upstream side of the balustrade. In preferred arrangements, a majority of baluster elements in the series, or all of the baluster elements in the series may have a cross-sectional shape that is that is adapted to cause a change in at least one air flow characteristic on a downstream side of the balustrade compared with the air flow on an upstream side of the balustrade, e.g. which is selected from a T-shape, a V-shape, a C-shape, an S-shape, a Z-shape, and a trapezium shape (‘A-shape'). Additionally, it has been found that the spacing gaps, which allow at least a limited airflow through the balustrade, help to prevent the formation of a low-pressure region on the downstream side of the balustrade, which advantageously prevents eddy currents from being formed from air flow over a top of the balustrade. In one example, a speed of an air flow that has passed through the balustrade according to the first aspect of the present invention may be reduced at at least one location downstream of the balustrade. For example, the average air flow speed passing through a predetermined volume downstream of the balustrade may be lower than the average airflow speed passing through a predetermined volume upstream of the balustrade. The predetermined volume may be a volume defined by the vertical and lateral extend of the balustrade, and extending fora depth of e.g. 1m downstream and upstream of the balustrade, respectively. Alternatively, or additionally, the air flow may be redirected by the balustrade along a different flow path, so that an intensity of air flow through at least one region on the downstream side of the balustrade is decreased, in essence creating a sheltered area. For instance, the balustrade arrangement may be configured to direct airflow away from a central region of the balustrade arrangement on the downstream side. Where a balustrade according to the first aspect of the present invention is incorporated into a balcony, the balustrade may redirect air away from a central space of the balcony that people most frequently occupy. In these ways, the balustrade according to the present invention is able to more efficiently shield a person on a downstream side of the balustrade from air flow. The lateral direction along which the baluster elements are arranged is perpendicular to the vertical direction in which the baluster elements extend. The vertically extending baluster elements arranged along the lateral direction may define upstream and downstream faces or surfaces of the balustrade, wherein the upstream face of the balustrade faces the direction from which an air flow approaches the balustrade, and the downstream face faces the direction towards which an air flow that has passed through the balustrade travels. A depth direction may be defined as a direction that is perpendicular to both the lateral and vertical directions, and may define the depth of the baluster elements between the upstream surface and downstream surface. Conveniently, the balustrade may be defined in relation to a coordinate system. More particularly, the lateral direction may be referred to as being along an X-axis, the depth direction may be referred to as being along a Y-axis, and the vertical direction may be referred to as being along the Z-axis. The total extension of the balustrade along the lateral direction / X-axis may be referred to as a width of the balustrade. The total extension of the balustrade along the depth direction / Y-axis may be referred to as a thickness or depth of the balustrade of the balustrade. The total extension of the balustrade along the vertical direction / Z-axis may be referred to as a height of the balustrade. The height of the balustrade may be substantially constant along the lateral length of the balustrade. Alternatively, the height of the balustrade may vary along the lateral length. The height of the balustrade may be in a range of from 80 cm to 150 cm, more preferably 100 cm to 120 cm, e.g. about 110 cm. Preferably, the height of the balustrade may not exceed a predetermined maximum value at any point along the lateral direction. The maximum height of the balustrade may be: 150 cm, 140 cm, 130 cm, 120 cm, 110 cm, or 100 cm. A reduced maximum height of the balustrade may restrict obstructions to a person’s view, particularly when the balustrade is incorporated into a balcony. The baluster elements may be rod-like structures. The material from which the baluster elements is not particularly limited, however in some arrangements, one or more of the baluster elements may be made of metal or plastic. The baluster elements may be attached to one or more rails that extend in the lateral direction, and which may define the upper and lower vertical bounds of the upstream and downstream balustrade faces. One or more of the baluster elements may have a length in a range of from 80 cm to 150 cm, more preferably 100 cm to 120 cm, e.g. about 100 cm, 110 cm, 120 cm, 130 cm, 140 cm or 150 cm. The baluster elements may all be the same length. Alternatively, one or more of the baluster elements may have a different length to one or more of the other baluster elements. Preferably, the cross-sectional shape of each baluster element is substantially constant along its entire vertical length. This may conveniently be achieved by forming the baluster elements using an extrusion process. That is, the baluster element may be extruded elements, e.g. extruded aluminium or steel forms. The plurality of baluster elements may be arranged in parallel along the lateral direction in a straight line, i.e. such that a straight (lateral) line can be drawn through a centre point of each baluster element. Alternatively, the baluster elements may be arranged in a staggered formation along the lateral direction, in which adjacent baluster elements are arranged on opposite sides of a lateral line. A T-shaped cross-sectional shape as defined herein may include a first straight-line segment and a second straight line segment, wherein an end of the first straight line segment is joined to a midpoint of the second straight line segment at a perpendicular angle (i.e. wherein an angle of 90° is formed between the first and second straight line segments). The inventors have observed that the use of T-shaped cross sectional baluster elements results in a buildup of pressure (e.g., ‘back pressure) on an upstream side of the balustrade, which causes an advantageous reduction in air flow speed on the downstream side of the balustrade. Additionally, the inventors have observed the formation of vortexing in the region immediately adjacent the downstream face. This vortexing is theorised to absorb air flow energy, and thereby further decrease the air flow speed on the downstream side. In some examples, when one or more baluster elements have a T-shaped cross-section, one or more of the one or more baluster elements having the T-shaped cross-section are orientated so that the first straight line of the T-shape extends outwardly in the depth direction toward the upstream side of the balustrade. In alternative arrangements, one or more of the one or more baluster elements having the T-shaped cross-section are orientated so that the first straight line of the T-shaped cross-sectional baluster elements extend along the depth direction toward the downstream side of the balustrade. In yet further arrangements, a first set of baluster elements having the T-shaped cross-section are orientated so that the first straight line of the T-shape extends outwardly in the depth direction toward the upstream side of the balustrade, and a second set of baluster elements having the T-shaped cross-section are orientated so that the first straight line of the T-shaped cross-sectional baluster elements extend along the depth direction toward the downstream side of the balustrade. A V-shaped cross-sectional shape as defined herein may include a first straight line segment and a second straight line segment, wherein the first straight line segment is angled relative to the second straight line segment at an acute angle. In some examples of the V-shape, a first end of the first straight line segment may join a first end of the second straight line segment. Alternatively, there may be a third straight line segment angled relative to both the first straight line segment and the second straight line segment, wherein a first end of the third straight line segment joins the first end of the first straight line, and a second end of the third straight line segment joins the first end of the second straight line segment - in other words, the V-shape may in some arrangements be a truncated V-shape. In some examples, when one or more baluster elements have a V-shaped cross-section, one or more of the one or more baluster elements having the V-shaped cross-section are orientated so that the second ends of the first and second straight line segments of the V-shape project outwardly toward the upstream side of the balustrade. In a particularly preferred example, the V-shaped baluster elements are orientated such that the product of the vector sum of the first straight line and the second straight line segments extends along, e.g. is parallel to, the depth direction. The inventors have observed that the use of V-shaped cross sectional baluster elements orientated in this way results in a buildup of pressure (e.g., ‘back pressure) on an upstream side of the balustrade, which causes an advantageous reduction in air flow speed on the downstream side of the balustrade. Additionally, the inventors have observed the formation of vortexing in the region immediately adjacent the downstream face. This vortexing is theorised to absorb air flow energy, and thereby further decrease the air flow speed on the downstream side. In alternative arrangements, the second ends of the first and second straight lines of the V-shape project toward the downstream side of the balustrade. A C-shaped cross-sectional shape as defined herein may include a curved line segment shaped like a broken circle or ellipse, in which the curved line segment forms the shape of a circle or ellipse with a portion of the perimeter missing. In some examples, when one or more baluster elements have a C-shaped cross-section, one or more of the one or more baluster elements having the C-shaped cross-section are orientated so that the missing part of the circle or ellipse defined by the curved line segment is orientated toward the upstream side of the balustrade. The inventors have observed that this arrangement creates a cushion of air on an upstream side of the balustrade that is greater than the size of the C-shaped baluster elements, which advantageously reduces the air flow speed. In alternative arrangements, the missing part of the circle or ellipse defined by the curved line is orientated toward the downstream side of the balustrade. An S-shaped cross-sectional shape as defined herein may include two oppositely disposed curved line segments arranged to form the shape of an ‘S’. In some examples, when one or more baluster elements have an S-shaped cross-section, one or more of the one or more baluster elements having the S-shaped cross-section are orientated so that the top and bottom of the ‘S’ shape are arranged on the upstream side and downstream sides respectively. Alternatively, the top and bottom of the ‘S’ shape may be arranged to lie along the lateral direction. A Z-shaped cross-sectional shape as defined herein may include a first straight line segment, and further include two additional straight line segments each extending from a respective end of the first straight line segment in opposite directions along parallel axes (e.g., both of the two additional line segments extend along a first axis, but are offset from one another along a second axis that is perpendicular to the first axis). In a preferred example, the first straight line segment is perpendicular to the two additional straight line segments (i.e. an angle of 90° is formed between the first line segment and each of the two additional straight line segments): this may be referred to as a ‘right angle Z shape’. Alternatively, the first straight line segment forms a non-perpendicular angle (i.e. an angle other than 90°) with each of the two additional straight line segment. In some examples, when one or more baluster elements have a Z-shaped cross-section, one or more of the one or more baluster elements having the Z-shaped cross-section are orientated so that the two additional straight line segments extend along the lateral direction (e.g., a ‘top’ and ‘bottom’ of the Z-shape are arranged on the upstream and downstream sides of the balustrade respectively). The inventors have observed that baluster elements having a Z-shaped cross-section and that are arranged with the two additional straight line segments of the cross-sectional shape extending parallel to the lateral direction very effectively redirect an incident air flow on the downstream side of the balustrade. More particularly, the inventors have found that when the ‘top’ straight line segment of the Z-shape crosssection (e.g., one of the two additional straight line segments that project from the first straight line segment) is on the upstream side of the balustrade, the direction in which it projects from the ‘middle’ straight line of the Z-shape is the direction that the wind is deflected in. Without being bound by theory, it has been suggested by the inventors that a cushioning effect and vortexing caused by the Z-shaped baluster elements, in combination with the Coanda effect, creates a ‘lozenge’-shaped region of relatively still air around the baluster element in the X-Y plane, which acts as a vane (e.g., a vane that is much larger than the cross-sectional size of the baluster element itself) to redirect airflow on the downstream side of the baluster. This effect can be advantageously used to create a sheltered region on the downstream side of the balustrade in which a person is sheltered from air flow. The use of balusters having a Z-shaped cross-sectional shape may be particularly preferred out of the possible range of cross-sectional shapes noted above, as it has been found that such a shape may provide particularly satisfactory modification of air flow characteristics) of an airflow incident on the balustrade arrangement incorporating Z-shaped balusters. In particular, it has been found that such arrangements can provide for redirection of an airflow incident on a balustrade arrangement in a desirable manner. Whilst the use of baluster elements having a Z-shaped cross-sectional form has been found to be particularly advantageous in redirecting airflow passing through the balustrade for the reasons described above, the inventors theorise that the benefits provided by this shape may be more generally achieved by baluster elements having a finned form (i.e. comprising one or more fins for redirection of an airflow incident on the baluster element). Accordingly, in a further aspect, the present invention provides a balustrade arrangement comprising: a plurality of vertically-extending baluster elements arranged in series along a lateral direction, with a spacing gap being defined between each pair of adjacent baluster elements in the series for allowing an air flow incident on the balustrade arrangement to pass through the balustrade arrangement from an upstream side to a downstream side, wherein one or more of the baluster elements in the series comprises one or more fins for redirection of the airflow incident on the baluster element. Provision of one or more fins on the baluster element(s) can cause a change in at least one air flow characteristic on a downstream side of the balustrade compared with the air flow on an upstream side of the balustrade. Optional features described in relation to the first aspect of the invention are also applicable to this aspect of the invention. The one or more fins preferably extend at least partially in the lateral direction. In other words, the baluster element may comprise a laterally-extending fin portion. This may allow redirection of an airflow incident on the baluster element towards the lateral direction in a region downstream of the balustrade, e.g. by means of the Coanda effect. In the context of Z-shaped baluster elements, each of the two additional straight line segments that project from the first straight line segment provide such a fin (a 'double-finned arrangement'). However, finned baluster elements are not limited to Z-shaped arrangements. For example, it is contemplated that an ‘L-shaped’ baluster element (i.e. a baluster element formed from two-perpendicularly arranged line segments in the shape of an ‘L’) may also provide a single-finned arrangement that allows for suitable redirection of an airflow incident on the baluster element towards the lateral direction in a region downstream of the balustrade. Where one or more of the baluster elements in the series comprises one or more fins, the fin(s) preferably extend along the entire vertical length of the baluster element (i.e. such that the baluster element has a substantially constant cross-sectional shape along its length). A trapezium-shaped (‘A-shaped) cross sectional shape as defined herein may include four sides, where at least two of the four sides extend parallel to one another, whilst the remaining two sides extend at an angle other than 90° with respect to the pair of parallel sides. It may be an isosceles trapezium-shaped cross section. In some examples, a ratio of the length of a longer base side of the trapezium cross section to the length of a shorter base side of the trapezium may in a range of from 2:1 to 9:1, e.g. may be any one of: 2:1,3:1,4:1,5:1,6:1,7:1,8:1,9:1. In some examples, when one or more baluster elements have a trapezium-shaped cross-section, one or more of the one or more baluster elements having the trapezium-shaped cross-section are orientated so that the two base sides of the trapezium are positioned on the upstream and downstream sides of the balustrade respectively (e.g., the two base sides both extend along the lateral direction of the balustrade). In a preferred example, the longer base side of the trapezium cross-section is positioned on the upstream side of the balustrade. The inventors have observed that this arrangement helps to advantageously reduce air flow on the downstream side. Alternatively, the longer base side of the trapezium cross-section may be positioned on the downstream side of the balustrade. The T-, V-, C-, and trapezium-shaped cross-sectional shapes may all be defined as having a single order of rotational symmetry. In some arrangements, the cross-sectional shapes of each of the baluster elements may have a single order of rotational symmetry. The S- and Z-shaped cross-sectional shapes may all be defined as having two orders of rotational symmetry. In some arrangements, the cross-sectional shape of each of the baluster elements may have two orders of rotational symmetry. In some examples, all of the baluster elements in the series may have the same cross-sectional shape. In particular, the cross-sectional shape of baluster elements may all be one of a T-, V-, C-, S-, Z- or trapezium-shaped (‘A-shaped’) cross-section. This may allow an improved downstream air flow profile to be formed, as each of the baluster elements will alter at least one airflow characteristic of the airflow in the same way, resulting in an improved cumulative effect on the downstream air flow. However, alternative arrangements are also contemplated in which one or more of the baluster elements have different cross-sectional shapes, which may allow one or more air flow characteristics to be advantageously altered in different ways in the downstream air flow. In some examples, all the baluster elements in the series are aligned to face in substantially the same direction. This may allow an improved downstream air flow profile to be formed, as each of the baluster elements will alter at least one air flow characteristic of the airflow in the same way, resulting in an improved cumulative effect on the downstream air flow. In some examples, one or more of the baluster elements in the series are aligned so as to face in a different direction to one or more of the other baluster elements in the series. For example, one or more of the baluster elements having a particular cross-sectional shape may be orientated 45, 90, 135, 180, 225, 270 or 315 degrees relative to one or more other baluster elements having the same cross-sectional shape. In some examples, a first set of baluster elements in the series are aligned in a first direction and a second set of baluster elements in the series are aligned in a second direction. The first set and the second set of baluster elements may collectively comprise all of the plurality of baluster elements, or alternatively may only represent a sub-set of the plurality of baluster elements. The first set of baluster elements may have the same cross-sectional shape as the second set of baluster elements. In some examples, the number of baluster elements in the first set is equal to the number of baluster elements in the second set. Alternatively, the number of baluster elements in the first set may be different to the number of balustrade elements in the second set. In some examples, the first set is arranged on a first side of the balustrade, and the second set is arranged on a second side of the balustrade that is opposite the first set. The first set of baluster elements may be arranged across a first half of the balustrade whilst the second set of baluster elements may be arranged across a second half of the balustrade, such that the first set of baluster elements and the second set of baluster elements meet at a lateral midpoint of the balustrade. In some examples, the baluster elements are arranged in an alternating pattern. In a preferred example, the baluster elements are arranged in an alternating pattern in which the cross-sectional shapes of adjacent balusters face in opposite directions. Alternatively, adjacent baluster elements may be grouped together into sets comprising two, three, four, five, six, seven, eight, nine, ten or more baluster elements, with each baluster element within each set being aligned along a single direction and the baluster elements of adjacent sets being rotated 180 degrees relative to one another. In further alternative examples, adjacent baluster elements, or adjacent sets of baluster elements, may be rotated by a non-180-degree angle relative to one another. For instance, adjacent baluster elements / sets of baluster elements may alternate between facing a first direction, and facing a second direction that is angled relative to the first direction by an angle of 30, 45, 60, 90, 120,135, 150 degrees. In some examples, when each of the baluster elements of the plurality of baluster elements have a crosssection with order two rotational symmetry, the plurality of baluster elements are split into a first set and a second set, and the cross-sectional shape of each baluster element of the first set of baluster elements is formed so as to be a mirror image of the cross-sectional shape of the baluster elements of the second set of baluster elements in a plane that is perpendicular to the lateral direction. In preferred examples, when each of the plurality of baluster elements have the Z-shaped cross-section, the plurality of baluster elements is split into a first set and a second set, and the cross-sectional Z-shape of each baluster element of the first set of baluster elements is formed so as to be a mirror image of the cross-sectional Z-shape of each of the baluster elements of the second set of baluster elements in a plane that is perpendicular to the lateral direction. The inventors have observed that this allows airflow to be redirected away from a specific region on the downstream side of the balustrade. More particularly, the first set of the baluster elements redirect the air flow in a first direction, and the second set of baluster elements that are a mirror image of the first set of baluster elements redirect the air flow in a second direction, such that a sheltered region is created in the space adjacent to the point(s) between baluster elements of the first set and baluster elements of the second set on the balustrade. In some examples, the first and second sets each contain an equal number of baluster elements. Alternatively, the first set of baluster elements may contain a different number of baluster elements to the second set of baluster elements. In some examples, the first set of baluster elements may be positioned on a first side of the balustrade, and the second set of baluster elements may be positioned on a second side of the balustrade. The first and second set of baluster elements and the second set of baluster elements may be divided at the lateral midpoint of the balustrade. This advantageously redirects airflow away from a region adjacent to a central lateral part of the balustrade. Alternatively, the first set of baluster elements and the second set of baluster elements may be separated at a different lateral point along the lateral width of the balustrade. In some examples, the baluster elements may be evenly spaced along the lateral direction. More specifically, each baluster element may be centred on a point along the lateral direction, and the distance between each of the central points of each baluster is equal. The skilled person would recognise that this distance between the central points of the baluster elements (e.g., the placement position of each baluster element) can be referred to as the ‘pitch’ of the baluster elements in the series. In some examples, the series of baluster elements has a pitch in a range of from 50 mm to 150 mm, or in a range of from 80 mm to 120. In some examples, the pitch may be no more than 150mm, 140 mm, 130 mm, 120 mm, 110 mm, 100 mm, 90 mm, 80 mm, 70 mm, 60 mm, 50mm, 40mm or 30mm. Moving the baluster elements closer together may reduce the air flow volume that is able to penetrate the balustrade at a time, which may advantageously reduce the air flow speed on the downstream side of the balustrade. A pitch of 120 mm or less or 100 mm or less may be particularly suitable for providing suitably modified air flow characteristics of an airflow incident on the balustrade. In alternative arrangements, one or more of the baluster elements of the plurality of baluster elements may not be evenly spaced relative to the remaining baluster elements of the plurality of baluster elements. A cross-sectional width of each baluster element can be defined as a maximum length of the baluster element in the lateral direction defined by the balustrade. More particularly, when a baluster element is arranged in the balustrade, the width of the baluster element is the lateral distance between the two most extreme lateral points on the cross-sectional shape of the baluster element. In some examples, the cross-sectional width of each baluster element of the plurality of baluster elements is in a range of from 10 mm to 150mm, e.g. 20mm to 80 mm. More preferably, the cross-sectional width of each baluster element of the plurality of baluster elements is in a range of from 30-50 mm. In some examples, the cross-sectional width of each baluster element of the plurality of baluster elements may be about 30 mm, about 35 mm, about 40 mm, about 45 mm or about 50 mm. A cross-sectional depth or thickness of each baluster element can be defined as a maximum length of the baluster element in the depth direction defined by the balustrade. More particularly, when a baluster element is arranged in the balustrade, the depth of the baluster element is the distance between the two most extreme points on the cross-sectional shape of the baluster element in the depth direction. In some examples, the cross-sectional depth of each baluster element of the plurality of baluster elements is in a range of from 10 mm to 150 mm, e.g. 20 mm to 80 mm. More preferably, the cross-sectional width of each baluster element of the plurality of baluster elements is in a range of from 30-50 mm. More preferably, the cross-sectional width of each baluster element of the plurality of baluster elements may be about 30 mm, about 35 mm, about 40 mm, about 45 mm or about 50 mm. In some arrangements, the cross-sectional width of each baluster element may be substantially equal to the cross-sectional depth or thickness of each baluster element. In other arrangements, the cross-sectional width may be different to the cross-sectional depth or thickness of each baluster element. A width of each spacing gap between each adjacent pair of baluster elements can be defined as the lateral distance between the baluster element on the first side of the spacing gap and the baluster element on the second side of the spacing gap. The width of the spacing gap may vary along the depth direction of the balustrade. A maximum width of each spacing gap between each adjacent pair of baluster elements can be defined as the largest width of the spacing gap across the depth direction (Y axis direction). In some examples, a maximum width of each spacing gap between adjacent baluster elements is in a range of from 50 mm to 150mm. It may be preferable for the maximum width of the spacing gap to be less than 100 mm to comply with regulations in various jurisdictions. For example, the maximum width of the spacing gap between each adjacent pair of baluster elements may be in a range of from 80-95 mm, e.g. no more than about: 80 mm, 95 mm, 90 mm or 95 mm. A minimum width of each spacing gap between each adjacent pair of baluster elements can be defined as the smallest width of the spacing gap across the depth direction (Y-axis direction). In some examples, a minimum width of each spacing gap between adjacent baluster elements is in a range of from 50 mm to 150mm. A predetermined minimum width of the spacing gaps may be desirable in order to ensure a minimum amount of airflow can pass between baluster elements in the series. For example, the minimum width of the spacing gap between each adjacent pair of baluster elements may be at least about: 90 mm, 80mm, 70 mm, 60 mm, 50 mm, 40 mm, or 30 mm. As noted above, the present invention has been devised in particular due to the inventor’s expertise in balcony systems. According to a second aspect of the present invention, there is therefore provided a balcony incorporating a balustrade arrangement according to the first aspect of the present invention. Employing a balustrade of the first aspect on a balcony may be particularly advantageous in view of the increased impact of wind on a balcony relative to other situations where balustrading is required (decking arrangements etc). The balcony may be attached to and supported by a building, such that at least one side of the balcony is bounded by a wall of the building whilst the remaining sides project into free space. The sides that project into free space may be referred to as ‘open sides’. In some alternative arrangements, the balcony may be bounded by a wall of the building on two side or on three sides. In these cases the remaining two side, or remaining one side may be open sides. A balustrade according to the first aspect of the present invention may form a partial or full barrier around the perimeter of the balcony. In some examples, a balustrade arrangement according to the first aspect of the present invention may be provided on all open sides of the balcony, such that the balustrade forms a protective barrier on each open side. The balustrade arrangement according to the first aspect of the invention provided on each side may be the same, or may be different (e.g., a first balustrade arrangement according to the first aspect of the present invention may be provided on a first side of the balcony, and a second balustrade arrangement according to a first aspect of the invention that is different to the first aspect may be provided on a second side of the balcony). Alternatively, the balustrade may only be provided on one or some, but not all, of the open sides. For example, the balustrade may encompass two open sides of the balcony (e.g., two sides that project from the building in a standard rectangular balcony), but not on the remaining side (e.g., a side that runs parallel to the building to which the balcony is attached to). This remaining side may be unobstructed, or may comprise an alternative balustrade arrangement not according to the first aspect of the present invention. For example, a solid balustrade, or a perforated sheet balustrade. In some examples, the balustrade arrangement according to the first aspect of the invention is configured to direct air flow away from a central portion of the balcony. This may reduce the air flow felt by a person in a central region of the balcony. According to a third aspect of the present invention, there is provided a building comprising a balcony according to the second aspect of the present invention. In some examples, the baluster elements of the balustrade of the balcony are configured to direct airflow toward the opening of the building. Whilst the above discussion focuses on balustrades suitable for use on balconies, it will be appreciated that balustrade arrangements according to the first aspect of the present invention may also find utility in use on alternative structures - further aspects of the present invention therefore include a staircase incorporating a balustrade arrangement according to the first aspect of the present invention, and a decking structure incorporating a balustrade arrangement according to the first aspect of the present invention. The invention includes the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided. Summary of the Figures Embodiments and experiments illustrating the principles of the invention will now be discussed with reference to the accompanying figures in which: Figs. 1(a)-(c) show a balustrade arrangement having Z-shaped baluster elements arranged according to a first example. Figs. 2(a)-(b) show plan view models of the air flow speed through the balustrade arrangement of Figs. 1(a)-(c). Figs. 3(a)-(c) show a balustrade arrangement having Z-shaped baluster elements arranged according to a second example. Figs. 4(a)-(b) show plan view models of the air flow speed through the balustrade arrangement of Figs. 3(a)-(c). Figs. 5(a)-(c) show a balustrade arrangement having V-shaped baluster elements. Figs. 6(a)-(c) a balustrade arrangement having T-shaped baluster elements all arranged in a first direction. Figs. 7(a)-(c) a balustrade arrangement having T-shaped baluster elements arranged in an alternating pattern. Figs. 8(a)-(c) a balustrade arrangement having C-shaped baluster elements. Figs. 9(a)-(c) a balustrade arrangement having trapezium shaped baluster elements. Figs. 10(a)-(c) a balustrade arrangement having S-shaped baluster elements. Fig. 11 shows a plan view of a balcony including multiple balustrade arrangements. Detailed Description of the Invention Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference. Figs. 1(a)-(c) show a balustrade arrangement 100 according to a first embodiment of the present disclosure. Fig. 1(a) shows a perspective view of the balustrade arrangement 100 having an upstream face 110 and a downstream face 120 (shown in Fig. 1(c)). The upstream face 110 faces the direction in which an air flow approaches the balustrade from (in other words, the upstream face faces an upstream airflow). The downstream face 120 faces the direction toward which the air flow travels having passed through the balustrade arrangement 100 (in other words, the downstream face faces a downstream air flow). The upstream and downstream faces 110 120 may alternatively be referred to as upstream / downstream surfaces respectively. The balustrade arrangement 100 comprises a plurality of baluster elements 130 arranged in series along a lateral axis (represented by double-ended arrow 102), with a spacing gap 140 between each pair of adjacent baluster elements 130 via which the airflow can pass through the balustrade arrangement 100. Each of the baluster elements 130 extends along a vertical axis that is perpendicular to the lateral direction (represented by double-ended arrow 104). In addition, the baluster elements 130 also have a defined depth in a direction that is perpendicular to both the lateral and vertical axes 102 104, hereinafter referred to as the depth axis (represented by double-ended arrow 106). A width of a baluster element 130 is defined as the lateral distance between the most extreme lateral points of the baluster element 130 when arranged in the balustrade arrangement 100. All of the baluster elements 130 of the present example have a uniform width, though the present disclosure is not limited in this way and in alternative embodiments one or more baluster elements may have different widths to other baluster elements. The width of each baluster element 130 in the present example is in the range of 30 mm to 50 mm, but other examples may have baluster element widths falling outside this range. A depth of each baluster element 130 is defined as the depth distance between the most extreme depth points of the baluster element 130 when arranged in the balustrade arrangement 100. All of the baluster elements 130 of the present example have a uniform depth, though the present disclosure is not limited in this way and in alternative embodiments one or more baluster elements may have different widths to other baluster elements. The depth of each baluster element 130 in the present example is in the range of 30 mm to 50 mm, but other examples may have baluster element depths falling outside this range. In the present example, the plurality of baluster elements 130 are evenly spaced along the lateral axis 102, such that each baluster element 130 is positioned at a fixed lateral distance from each adjacent baluster element 130. The skilled person would recognise that in examples such as this where the plurality of baluster elements 130 are evenly spaced, the distance between adjacent baluster elements 130 can be referred to as the ‘pitch’ of the baluster elements 130 in the series. However, the present disclosure is not limited to examples where the baluster elements are evenly spaced. For example, in alternative arrangements, baluster elements may be spaced from one another by differing amounts. The pitch of the baluster elements in the present example is in the range of 100 mm to 120 mm. However, the present disclosure is not limited in this way, and there may also be examples in which the pitch is less than 100 mm or greater than 120 mm. Smaller pitches may be particularly advantageous, as the smaller widths result in a greater cumulative effect of the baluster elements 130 on the airflow. Further in the present example, the baluster elements 130 comprise a ‘Z-shaped’ cross-sectional shape in a plane that is perpendicular to the Z-direction (i.e., a plane defined by the lateral and depth axes). As shown in Fig. 1(b), which is a planar view of the Z-shaped cross-sectional shape, the Z-shape comprises a first straight line segment 132, termed the middle straight line segment. The Z-shape further comprises two additional straight line segments 134 136, respectively termed the top straight line segment 134 and the bottom straight line segment 136, which are each attached to a respective end of the first straight line segment 132. Both of the additional straight line segments 134 136 extend away from the first straight line segment 132 in a perpendicular manner, in opposite directions. More specifically, the top straight line segment 134 extends away from the middle straight line segment 132 toward the right with reference to the page, and the bottom straight line segment 136 extends away from the middle straight line segment 132 toward the left with reference to the page. In this way, the Z-shape describes a right-angled Z-shape. Each of the top straight line segment 134 and the bottom straight line segment 136 can be considered to be ‘fin’ portions extending from the middle straight line segment 132. The inventors have observed that the Z-shape described above is particularly effective at redirecting air flow (as described below). However, it is intended that the Z-shaped cross-section be interpreted more broadly than this particular example. In particular, in other arrangements the straight line 132 may instead be angled at a non-perpendicular angle (i.e. at an angle other than 90°) to the top and bottom lines of the Z-shape, so as to form a more traditional ‘Z’ letter shape. In the balustrade arrangement 100 shown in Fig. 1, the top and bottom line segments 134 136 are arranged so as to be positioned on the upstream and downstream faces 110 120 of the balustrade arrangement 100 respectively. More specifically, the top line segment 134 and the bottom line segment 136 are arranged such that they extend parallel to the lateral axis 102 of the balustrade arrangement 100. Further in the balustrade arrangement 100 shown in Fig. 1, each of the baluster elements 130 are oriented in the same direction. More particularly, each of the baluster elements 130 are arranged so that the straight line segments on the upstream face 110 of the balustrade arrangement 100 (i.e., either the top line segments 134 of each balustrade element 130 or the bottom line segments 134 of each baluster element 130) all project in a first lateral direction, whist each of the straight line segments on the downstream face 120 of the balustrade arrangement 100 (i.e., either the bottom line segments 136 of each of the baluster elements 130 if the top line segments 134 are all arranged on the upstream face 110, or the top line segments 134 of each of the baluster elements 130 if the bottom line segments 136 are all arranged on the upstream face 110) all project in a second lateral direction that is opposite the first lateral direction. Fig. 1(c) shows a 2D model of the air flow through the balustrade arrangement 100 of Fig. 1(a). The air flow approaches the balustrade arrangement 100 from the left-hand side of the Fig. (with reference to the page), which represents an upstream side of the balustrade 100, and moves away from the balustrade arrangement 100 on the right-hand side of the Fig. (with reference to the page), which represents the downstream side of the balustrade 100. As can be seen in Fig. 1(c), as the air flow passes through the spacing gaps 140, the interaction of the air flow with the baluster elements 130 causes the air to be redirected upward (with respect to the page). More specifically, the airflow is redirected toward the direction in which the line segment of the Z-shaped cross-sectional shape on the upstream face of the balustrade arrangement 100 (i.e., either the top line segment 134 or the bottom line segment 136) projects away from the middle line segment 132 of the Z-shaped cross-sectional shape. From the modelling shown in Fig. 1 (c), the inventors theorize that the Z-shaped cross-sectional shape of the baluster elements 130 is creating a cushioning effect and / or vortexing in the air flow, which in turn is causing a ‘lozenge-shaped’ region 150 of'dead-space' around the baluster element 130 in which there is little to no air flow. This lozenge shaped region 150, in combination with the Coanda effect, effectively acts as an airflow vane which redirects the air flow towards the lateral direction as it passes through the balustrade. Particularly advantageously, it has been found that the effective size of the lozenge-shaped region 150 (and thus the size of the effective air flow vane) is larger than the size of the corresponding baluster element 130. As a result, the vane is able to impart a greater redirecting force on the air flow and / or act on the air flow for a longer period of time, such that the overall redirection is greater than would otherwise be achieved. As all of the z-shaped baluster elements 130 are oriented in the same way in the present example, each of the baluster elements 130 redirects the airflow in the same way. Thus, the overall effect of the balustrade arrangement of the present example is to create a sheltered region on the downstream side that is adjacent to one side of the baluster arrangement (e.g., the side of the baluster arrangement that the baluster elements 130 are redirecting the air flow away from). This is described in more detail below with reference to Fig. 2. Fig. 2 shows 2D plan view models of the airflow speed through the balustrade arrangement of Fig. 1. More particularly, Fig. 2(a) shows a plan view model of the air flow speed through a baluster arrangement 100 wherein the baluster element centres are arranged at intervals of 120 mm (e.g., the pitch of the series of baluster elements is 120 mm), and Fig. 2(b) shows a plan view model of the air flow speed through a baluster arrangement 100 wherein the baluster element centres are arranged at intervals of 100mm (e.g., the pitch of the series of baluster elements is 100 mm). In both cases, the direction of air flow is to the right with reference to the page in the landscape orientation, and the baluster elements 130 are arranged so that the straight line of the Z-shaped cross-sectional shape that is arranged along the downstream surface (i.e., either the top line 134 or the bottom line 136) projects away from the middle line 134 upward with reference to the page in the landscape orientation. In both cases, the baluster arrangement 100 redirects the airflow away from a downstream region 160a 160b adjacent to the bottom (with reference to the page in the landscape orientation) of the baluster arrangement 100. As a result, the air flow speed within these regions 160a 160b is reduced compared to the air flow speed of either the upstream air flow or the downstream air flow in a region outside of the sheltered downstream region. It can also be seen that a width of the sheltered downstream region 160a 160b (i.e., the width of the downstream region defined approximately by the line along which there is a sharp drop in air flow speed) increases as the distance from the balustrade arrangement 100 increases, as a result of the air flow that passes through the lowest (with reference to the page in the landscape orientation) spacing gaps 141 of the balustrade arrangement continuing to travel upward after passing the balustrade arrangement 100. This increasing width of the downstream region 160a 160b tails off at a shoulder region 162a 162b, after which point the width of the sheltered regions 160a 160b are substantially constant. In comparison, the sheltered region 162a grows more slowly that the sheltered region 162b, as a result of the smaller pitch of the balustrade elements in Fig. 2(b) causing an increased redirection effect on the airflow in Fig. 2(b) compared with the airflow in Fig. 2(a). From this data, it can be concluded that provision of a smaller pitch for the baluster elements may increase the size of the sheltered area in such balustrade arrangements. Referring now to Figs. 3(a)-(c), there is shown a balustrade arrangement 200 according to a second embodiment of the present invention. More particularly, Fig. 3(a) shows a perspective view of the balustrade arrangement 200, Fig. 3(b) shows a cross sectional view of two of the baluster elements 230 of the balustrade arrangement 200, and Fig. 3(c) shows a 2D model of the air flow through the balustrade arrangement 200. The balustrade arrangement 200 of Figs. 3(a)-(c) is similar to the balustrade arrangement 100 of Figs. 1(a)-(c), and like features are given like reference numerals incremented by 100. In particular, both the balustrade arrangement 200 and the balustrade arrangement 100 include Z-shaped cross-sectional balustrade elements. Further, the top and bottom line segments 234 236 of the baluster elements 230 in the balustrade arrangement 200 are again arranged so as to be positioned on the upstream and downstream faces 210 220 of the balustrade arrangement 200 respectively. More specifically, the top line segment 234 and the bottom line segment 236 are parallel to the lateral axis 202 of the balustrade arrangement 100. However, in the balustrade arrangement 200, the baluster elements 230 are arranged so that a first group of the baluster elements 230a are orientated in a different direction to a second group of baluster elements 230b. More particularly, the baluster elements of the first group 230a are all arranged on a first side of the balustrade arrangement 200, and are oriented along a single direction in which the straight line segment of the Z-shaped cross-sectional shape arranged on the downstream side of the balustrade arrangement (i.e., either the top line segment 234a or bottom line segment 236a) all project toward the lateral middle plane of the balustrade arrangement (indicated by the dashed line 208). On the other hand, the baluster elements of the second group 230b are all arranged on a second side of the balustrade arrangement that is opposite the first side of the baluster arrangement 200, and all are also aligned along a single direction in which the straight line segments of the Z-shaped cross-sectional shape arranged on the downstream side of the balustrade arrangement (i.e., either the top line segment 234 or bottom line segment 236) all project toward the lateral middle plane of the balustrade arrangement (indicated by the dashed line 208). In other words, the baluster elements of the first group 230a and the baluster elements of the second group 230b are arranged to be mirror images of one another. This is shown most clearly in Fig. 3(b). As shown in Fig. 3(c), the arrangement of the baluster elements 230 into groups 230a and 230b causes an airflow to be redirected away from a downstream region that is adjacent the dividing point between the baluster element groups 230a and 230b on the baluster arrangement 200, Thus, a sheltered region can be advantageously created in a downstream region of the balustrade arrangement 200, in which the air flow is advantageously reduced. In the present example of Fig. 3, the dividing line between the baluster element groups 230a 230b is in a middle of the baluster arrangement, such that the sheltered region can advantageously be created approximately in line with the centre of the balustrade arrangement 200 (e.g., where a person sheltering behind the balustrade arrangement 200 is most likely to be located). However, the present disclosure is not limited in this way, and alternative embodiments are envisaged in which the dividing line is positioned at various points along the lateral width of the balustrade arrangement. Moreover, embodiments are also envisaged wherein the baluster element groups are not split onto the two sides of the balustrade arrangement, but are instead dispersed amongst members of the other group. For example, examples are envisaged in which baluster elements of the first group 230a are dispersed in an alternating pattern with baluster elements of the second group 230b, or where subgroups of baluster elements from the first group, consisting of one, two, three or more baluster elements 230, are adjacent to one another, and are dispersed in an alternating arrangement with subgroups of baluster elements from the second group 230b, consisting of one, two, three or more baluster elements 230. Such arrangement may allow for specific tailoring of the shape of the sheltered region provided by the balustrade arrangement. Fig. 4 shows 2D plan view models of the air flow speed through the balustrade arrangement of Fig. 3. More particularly, Fig. 4(a) shows a plan view model of the air flow speed through a balustrade arrangement 200 wherein the air flow is incident on the balustrade arrangement 200 at a normal angle to the surface of the balustrade, and Fig. 4(b) shows a plan view model of the air flow speed through a balustrade arrangement 200 wherein the air flow is incident on the balustrade arrangement 200 at a 45 degree angle relative to the surface of the balustrade arrangement 200. In both cases, a sheltered region 260a 260b is created downstream of the balustrade arrangement 200, which increases in width with increasing downstream distance from the balustrade arrangement 200. The sheltered region 260a and 260b extends along an axis that is parallel to the upstream air flow direction. That is, in Fig. 3(a) when the air flow is normal to the surface of the balustrade arrangement 200, the sheltered region 260a extends away from the balustrade arrangement 200 on the downstream side along an axis that is normal to the surface of the balustrade arrangement 200, and in Fig. 3(b) when the air flow is incident at a 45 degree angle to the surface of the balustrade arrangement 200, the sheltered region 260b extends away from the balustrade arrangement 200 on the downstream side along an axis that is angled at a 45 degree angle to the surface of the balustrade arrangement 200. This figures demonstrate that provision of a sheltered region is achieved regardless of the angle of incidence of the airflow on the balustrade arrangement. Referring to Figs. 5-9(a)-(c), there is shown a plurality of balustrade arrangements 300-700 according to third, fourth, fifth, sixth and seventh embodiments of the present invention. More particularly, Figs. 5-9(a) show perspective views of the balustrade arrangements 300-700, Figs. 5-9(b) show a cross-sectional view of the baluster elements 330-730 of the balustrade arrangement 300-700, and Figs. 5-9(c) show a 2D model of the air flow through the balustrade arrangements 300-700. The balustrade arrangements 300-700 of Figs. 5(a)-(c) is similar to the balustrade arrangement 100 of Figs. 1(a)-(c), and like features are given like reference numerals incremented by 200, 300, 400, 500 and 600 respectively. In particular, both the balustrade arrangements 300-700 and the balustrade arrangement 100 include baluster elements arranged along a lateral direction, which are all oriented in a single direction. However, the cross-sectional shape of the plurality of baluster elements 330-730 are different to the cross-sectional shape of the plurality of baluster elements 130, as described below. Referring to Fig. 5(a)-5(b), the cross-sectional shape of the baluster elements 330 is ‘V-shaped’ (specifically, a truncated V-shape). More particularly, the cross-sectional shape of the baluster elements 330 include a first straight line segment 334 (termed the left straight line segment 334) and a second straight line segment 336 (termed the right straight line segment 336) which are angled relative to one another at an acute angle. The cross-sectional shape of the baluster elements 330 further include a third, middle, straight line segment 332 having a first end 332a and a second end 332b, wherein the first end 332a of the middle line segment 332 is connected to an end of the left straight line segment 334, and the second end 332b of the middle line segment 332 is connected to an end of the right straight line segment 336. The baluster elements 330 of the balustrade arrangement 300 are oriented so that the middle line segment 332 is arranged on the downstream face 320 of the balustrade arrangement 300. More particularly, the middle line segment 332 extends along the lateral direction 302 defined by the balustrade arrangement 300, whilst the left straight line segment 334 and the right straight line segment 336 project outward toward the upstream side of the balustrade arrangement 300 such that an opening 335 defined between the left straight line segment 334 and the right straight line segment 336 is arranged along the upstream face 310 of the balustrade arrangement 300. However, the present disclosure is not limited to this example, and alternative examples are envisioned in which the V-shaped baluster elements are oriented in a different manner. Referring to Fig. 6(a)-6(b), the cross-sectional shape of the baluster elements 430 is ‘T shaped’. More particularly, the cross-sectional shape of the baluster elements 430 includes a first line segment 432, and a second line segment 434 arranged to join to the midpoint of the first line segment 432, wherein the first line segment and the second line segment are arranged at a perpendicular angle (90°) with respect to one another. The baluster elements 430 of the baluster arrangement 400 are oriented so that the second line segment 434 projects toward the upstream face 410 of the balustrade arrangement 400, and the first line segment 432 extends along the downstream face 420 of the balustrade arrangement 400. However, the present disclosure is not limited to this example, and alternative examples are envisioned in which the T-shaped baluster elements are oriented in a different manner. Referring to Fig. 7(a)-7(b), the cross-sectional shape of the baluster elements 530 is ‘C-shaped’. More particularly, the cross-sectional shape is a curved line 532 that forms into the shape of a broken circle, in which the two ends of the curved line 532a 532b are separated by a gap 535. The baluster elements 530 of the baluster arrangement 500 are oriented so that the gap 535 is arranged along the upstream face 510 of the balustrade arrangement 500. However, the present disclosure is not limited to this example, and alternative examples are envisioned in which the C-shaped baluster elements are oriented in a different manner. Referring to Fig. 8(a)-8(b), the cross-sectional shape of the baluster elements 630 is ‘trapezium-shaped’. More particularly, the cross-sectional shape of the baluster elements 630 is ‘isosceles trapezium-shaped’. The trapezium shaped cross section comprises two leg sides 532a 532b, a long base side 534 and a short base side 536. The baluster elements 630 of the baluster arrangement 600 are oriented so that the long base side 634 of the trapezium-shaped cross-sectional shape is arranged along the downstream face 620 of the baluster arrangement 600, and the short base side 636 of the trapezium-shaped cross-sectional shape is arranged along the upstream face 610 of the baluster arrangement 600. However, the present disclosure is not limited to this example, and alternative examples are envisioned in which the trapezium-shaped baluster elements are oriented in a different manner. Referring to Fig. 9(a)-9(b), the cross-sectional shape of the baluster elements 730 is ‘S-shaped’. The baluster elements 730 of the baluster arrangement are oriented so that a top curved portion of the S-shape 734 and a bottom curved portion of the S-shape 736 are arranged along the upstream face 710 of the balustrade arrangement 700 and downstream face 720 of the balustrade arrangement 700 respectively. However, the present disclosure is not limited to this example, and alternative examples are envisioned in which the S-shaped baluster elements are oriented in a different manner. The baluster arrangements 300-700 each cause vortexing and redirection of the air flow in a downstream space, as shown in Figs. 5-9(c). This vortexing absorbs energy from the air flow, advantageously reducing the air flow speed on the downstream side. Additionally, in several of these balustrade arrangements, particularly the balustrade arrangements 300-400, the balustrade elements create a pressure build up on an upstream side of the balustrade. This pressure build up provides a cushioning effect that further advantageously reduces the air flow speed on a downstream side of the balustrade arrangement. Referring to Figs. 10(a)-(c), there is shown a balustrade arrangement 800 according to an eighth embodiment of the present invention. More particularly, Fig. 10(a) shows a perspective view of the balustrade arrangement 800, Fig. 10(b) shows a cross-sectional view of two of the baluster elements 830a 830b of the balustrade arrangement 800, and Fig. 10(c) shows a 2D model of the air flow through the balustrade arrangement 800. The balustrade arrangement 800 of Fig. 10(a)-(c) is similar to the balustrade arrangement 400 of Figs. 6(a)-(c), and like features are given like reference numerals incremented by 400 respectively. In particular, both the balustrade arrangement 800 and the balustrade arrangement 400 include baluster elements having a T-shaped cross-section. However, the balustrade arrangement 800 differs from the balustrade arrangement 400 in two keys ways which are described below. First, the baluster elements 830 are arranged in an alternating pattern, in which adjacent baluster elements 830 point in opposite directions. More particularly, and with reference to Fig. 10(b), two adjacent baluster elements 830 can be split into a first baluster element 830a and a second baluster element 830b. The first baluster element 830a is orientated so that a second straight line segment of the cross-sectional T-shape 834a is pointed toward the upstream face 810 of the balustrade arrangement 800 and the first straight line segment is arranged along the downstream face 820 of the balustrade arrangement 810, and the second baluster element 830b is orientated so that a second straight line segment of the cross-sectional T-shape 834b is pointed toward the downstream face 820 of the balustrade arrangement 810 and the first straight line segment is arranged along the upstream face 810 of the balustrade arrangement 800. Second, whereas the baluster elements 430 are arranged along a lateral axis 802 of the balustrade arrangement 800, the baluster elements 830 are staggered on either side of a lateral axis 802 of the balustrade arrangement 800. Referring to Fig. 11, there is shown a balcony 1000 including a plurality of balustrade arrangements 1100 1200 1300. The balcony is attached to a building 1010, which includes an opening 1020 onto the balcony 1000 from an interior of the building 1010. The plurality of balustrade arrangements 1100 1200 1300 are arranged on different sides of the balcony 1000. More specifically, a first balustrade arrangement 1100 and a second balustrade arrangement 1200 are positioned on the two respective sides of the balcony 1000 that meet the building 1010, and a third balustrade arrangement 1300 is arranged on a front of the balcony opposite the building 1010. In the present example, the balustrade arrangements are all different. Such arrangements may be advantageous where it is desired to tailor the air flow profile across the balcony - the combined effect of the plurality of different balustrade arrangements may allow for a specific air flow profile across the balcony to be achieved. In the figure shown here, only a portion of the balcony is covered by a balustrade arrangement according to the present disclosure (i.e., the balustrade arrangement 1300 provided on the front of the balcony (having T-shaped baluster elements) and the balustrade arrangement 1200 provided on the right hand side of the balcony (having trapezium-shaped baluster elements)). However, the present disclosure is not limited in this way, and instead a single balustrade arrangement may be provided for the entire balcony of the balcony that accords with the balustrade arrangements 100-800 of the present disclosure. The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof. While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention. For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations. Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. Throughout this specification, including the claims which follow, unless the context requires otherwise, the word “comprise” and “include”, and variations such as “comprises”, “comprising”, and “including” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to a numerical value is optional and means for example + / -10%.

Claims

1. A balustrade arrangement comprising:a plurality of vertically-extending baluster elements arranged in series along a lateral direction, with a spacing gap being defined between each pair of adjacent baluster elements in the series for allowing an air flow incident on the balustrade arrangement to pass through the balustrade arrangement from an upstream side to a downstream side,wherein one or more of the baluster elements in the series comprises one or more fins for redirection of the air flow incident on the baluster element.

2. A balustrade arrangement comprising:a plurality of vertically-extending baluster elements arranged in series along a lateral direction, with a spacing gap being defined between each pair of adjacent baluster elements in the series for allowing an air flow incident on the balustrade arrangement to pass through the balustrade arrangement from an upstream side to a downstream side,wherein one or more of the baluster elements in the series have a cross-sectional shape that is selected from: a T-shape, a V-shape, a C-shape, an S-shape, a Z-shape, and a trapezium shape.

3. The balustrade arrangement of claim 1 or claim 2, wherein all of the baluster elements in the series have the same cross-sectional shape.

4. The balustrade arrangement according to any one of claims 1 to 3 wherein the cross-sectional shape of each baluster element is substantially constant along its entire vertical length.

5. The balustrade arrangement according to any one of claims 1 to 4, wherein all the baluster elements in the series are aligned to face in substantially the same direction.

6. The balustrade arrangement of any one of claims 1 to 4, wherein one or more of the baluster elements in the series are aligned so as to face in a different direction to one or more of the other baluster elements in the series.

7. The balustrade arrangement of any one of claims 1 to 4 or claim 6, wherein a first set of baluster elements in the series are aligned in a first direction and a second set of baluster elements in the series are aligned in a second direction.

8. The balustrade arrangement of claim 7, wherein the baluster elements are arranged in an alternating pattern in which the cross-sectional shapes of adjacent balusters face in opposite directions.

9. The balustrade arrangement of claim 7, wherein the baluster elements of the first set of baluster elements are positioned on a first side of the balustrade, and the baluster elements of the second set of baluster elements are positioned on a second side of the balustrade.

10. The balustrade arrangement of any one of claims 1 to 9, wherein each of the plurality of baluster elements have a Z-shaped cross-section, the plurality of baluster elements is split into a first set and a second set, and the cross-sectional Z-shape of each baluster element of the first set of baluster elements is formed so as to be a mirror image of the cross-sectional Z-shape of each of the baluster elements of the second set of baluster elements in a plane that is perpendicular to the lateral direction.

11. The balustrade arrangement of any one of claims 1 to 10, wherein the series of baluster elements has a pitch of 120 mm or less.

12. The balustrade arrangement of any one of claims 1 to 11, wherein a cross-sectional width of each baluster element of the plurality of baluster elements is in a range of from 30 mm to 50 mm.

13. The balustrade arrangement of any one of claims 1 to 12, wherein a cross-sectional depth of each baluster element of the plurality of baluster elements is in a range of from 30mm to 50 mm.

14. The balustrade arrangement of any one of claims 1 to 13 wherein the balustrade arrangement is configured to direct the air flow incident on the balustrade arrangement away from a central region of the balustrade arrangement, on the downstream side of the balustrade arrangement.

15. A balcony incorporating a balustrade arrangement according to any one of claims 1 to 14.

16. The balcony of claim 15, wherein the balustrade is configured to direct airflow away from acentral portion of the balcony.

17. A building comprising a balcony according to claim 15 or claim 16, and an opening onto the balcony from an interior of the building.

18. The building of claim 17, wherein the baluster elements of the balustrade are configured to direct air flow toward the opening.

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