Modular building unit

Abstract

There is disclosed a modular building unit (10), a modular building assembly (12) comprising the modular building unit, a building (28) comprising the modular building unit / assembly, and a method of c

Description

The present invention relates to a modular building unit, a modular building assembly comprising a modular building unit, a building comprising the modular building unit / assembly, and a method of constructing a building (particularly a hybrid building) comprising a modular building unit. In particular, but not exclusively, the present invention relates to a modular building unit comprising a structural frame having a floor frame portion, a ceiling frame portion, and a support structure extending between and connecting the floor frame portion to the ceiling frame portion. Prefabricated buildings (also known as ‘modular’ buildings) are well known in the construction industry, particularly modular residential buildings such as houses, flats or apartments, and hotels. Modular buildings typically comprise a series of building units which are constructed in a factory, transported to a final location (or site) for the building, and then arranged in a predetermined configuration and coupled together to form the finished building. The modular building units are typically constructed to a substantially assembled form in the factory, in which they can be transported to the final location. Construction of the building can involve stacking one or more upper modular building unit on a lower such unit, so that the upper unit is supported by the lower unit. Hybrid buildings have been developed by the applicant which comprise a first building section that is constructed at a final location for the building, and a second building section comprising one or more modular building unit constructed in a dedicated facility, away from the final location. A hybrid building of this type can provide advantages including that: construction of the first building section is simplified, with more complex parts of the building provided in the section formed by the modular building unit(s); and the first building section can provide the primary living space in the building, without being constrained by construction and transport limitations imposed on the modular building unit(s). The hybrid buildings and associated construction techniques are disclosed in International patent publication nos. WO2022 / 243696, WO2022 / 243695, WO2022 / 243694 and WO2022 / 243693, as well as International patent application no. PCT / EP2023 / 063435. Most modular building units comprise a structural frame including a floor portion, a ceiling portion, and a support structure which serves to connect the ceiling portion to the floor portion, and to transmit structural loading from the ceiling portion to the floor portion. The modular building units are typically generally quadrilateral-shape in plan view (e.g. rectangular). The support structure includes support posts or columns which extend between the floor and ceiling portions. Support posts are typically provided at comers of the unit, with additional posts positioned around its perimeter. The support structure can also include transverse bracing stmts extending between at least some of the support posts. Walls are formed by connecting wall panels or sheets to the support posts. Options for the support structure include a metallic frame, which can be cold-formed (e.g. of light gauge steel), hot formed (e.g. of hot rolled steel), or combinations of the two. A hot-formed metallic frame may provide a sufficiently rigid structure so that additional perimeter support posts and bracing struts can be dispensed with (or the number of posts / struts reduced). Other options include timber-based frames. The floor portions of conventional modular building units are relatively deep (considered in a vertical sense), and often have depths which are greater than their ceiling portions. The floor portions usually comprise a frame formed from a number of beams and / or joists, which can have a depth of perhaps 30cm (almost 12”) or more. It has conventionally been necessary to provide such a deep floor frame because modular building units forming a lowermost storey or floor of a building are often positioned on a concrete foundation. A thick layer of insulation material must be therefore accommodated within the floor portion itself, in order to reduce thermal energy transfer between the foundation and the modular building unit. It has also been considered necessary to provide a deep floor frame, to provide rigidity to the structure, including for transport. Modular building units having deep floor frames can cause problems in hybrid buildings of the type described above, including that matching a floor level of the building section formed from the modular building unit(s) with that formed by the section constructed at the final building location can be challenging. In addition, the ceiling frames of known modular building units can also be relatively deep. Where modular building units are stacked to form a multi-storey building, this can result in a very deep structure at the intersection between the ceiling of a lower unit, and the floor of an upper unit. This complicates the transition for a staircase between the units, and also impacts on material usage, weight and costs. It will be understood that these can also be issues in fully modular buildings, including that steps must be taken to accommodate the deep floor during the construction process. According to a first aspect of the present invention, there is provided a modular building unit comprising a structural frame, the structural frame comprising: a floor frame portion having a first depth, the floor frame portion configured to support a planar floor structure; a ceiling frame portion having a second depth; and a support structure extending between and connecting the floor frame portion to the ceiling frame portion; in which a ratio of the first depth of the floor frame portion relative to the second depth of the ceiling frame portion is at least about 1:3; and in which the modular building unit defines a circulation space configured to provide at least one access function for a building comprising the modular building unit. The depth of the floor and ceiling frame portions may be considered or measured in a generally vertical direction. Reference may alternatively be made to vertical heights of the floor and ceiling frame portions. The provision of a modular building unit having the stated depth relationship may provide particular benefits in the context of a hybrid building of the type described above. This includes facilitating matching a floor level of a building section comprising the modular building unit with a floor level of a section of the building constructed at its final location. For example, both the section formed by the modular building unit, and the section constructed at the final location, may rest on a common foundation. It may be desirable to maintain common (or uniform) floor levels within the constructed building, to avoid a change in floor height between the building sections. Providing floor and ceiling frame portions with such a depth relationship may have the result that the floor frame portion depth can be relatively shallow, so that only a small height difference need be accommodated. This may provide additional benefits in terms of material and cost savings. In addition, arranging the floor and ceiling frame portions so that they have depths in the stated ratio may have the result that the ceiling frame portion can be made to be relatively deep, without adversely impacting the depth of the floor frame portion. This may enable the ceiling frame portion to provide a majority of the structural strength for the modular building unit, and space to accommodate e.g. utilities such as: wastewater conduits for wet facilities provided in an upper modular building unit stacked on a lower such unit; water supply conduits; ventilation conduits; electrical power and communication cables. The shallow floor frame portion may also help to reduce a depth of structure at the intersection between the ceiling of a lower unit and the floor of an upper such unit. The ratio of the first depth relative to the second depth may be up to about 1:6. The ratio of the first depth relative to the second depth may be in a range of between about 1:3 to about 1:6. A ratio falling within this range may provide a good balance of a relatively thin floor portion, and a ceiling portion that can provide a majority of the structural strength for the modular building unit and / or space to accommodate required utilities. The first depth of the floor frame portion may be up to about 70mm (—2.756”). A floor frame portion having such a depth may be relatively shallow, and may be significantly shallower than floor frame portions of conventional modular building units. In a hybrid building comprising a first section constructed at a final location, and a second section comprising the modular building unit, a level of a floor of the first section may be brought up to that of the second section by applying e.g. a cementitious screed to a floor support structure of the first section. It may be preferred to restrict the first depth to no more than around 70mm, which may be a maximum optimal height for such a screed. The first depth may be up to around 50mm (~1.968”). The first depth may be in a range of about 50mm to about 70mm. A depth in the region of around 50mm may be preferred. The second depth of the ceiling frame portion may be at least about 150mm (—5.906”). The second depth may be up to about 300mm (~11.811”). The second depth may be in a range of about 150mm to about 300mm. A depth in the region of about 250mm may be preferred. A modular building unit having such floor and ceiling frame portion first and second depths may provide a good balance of benefits, e.g. in terms of minimising disruption to accommodate the floor frame and / or minimising a depth of structure at a transition between lower and upper modular building units, whilst providing a sufficiently strong ceiling frame portion and / or depth in the ceiling frame to accommodate utilities. The modular building unit may be generally quadrilateral-shape in plan view, and may be generally rectangular. The floor frame portion may comprise a floor frame. The first depth of the floor frame portion may be defined or described by the floor frame. The floor frame may have an upper surface. The floor frame may have a lower surface. The first depth may be defined between the upper and lower surfaces. The floor frame may comprise, and / or may be formed from or defined by, a plurality of elongate frame members. The elongate frame members may define the upper and / or the lower surfaces. The floor frame may comprise a perimeter frame structure, which may comprise elongate beams. The perimeter frame structure may comprise first and second side beams, which may be disposed substantially parallel to one another. The perimeter frame structure may comprise first and second end beams, which may be disposed substantially parallel to one another. The first and second side beams, and the first and second end beams, may together form or define a majority or all of the perimeter frame structure. The floor frame may comprise at least one support beam which may extend in a direction between the first and second end beams, and disposed between the side beams. The floor frame may comprise a plurality of elongate joists. At least one joist may extend in a direction between the first and second side beams. At least one joist may be arranged to have a depth which is different to (e.g. less than) the depth of beams forming the perimeter frame structure (said beams being of the first depth). The floor frame may be configured to support the planar floor structure. The planar floor structure may define a floor of the modular building unit. The planar floor structure may comprise, or may be defined by, one or more planar floor panel. The first depth of the floor frame portion may not include said planar floor structure, other structural or insulative material positioned on said floor structure, and / or any decorative floor finish or covering (e.g. carpet or tiles) positioned on said floor structure. The ceiling frame portion may comprise a ceiling frame. The second depth of the ceiling frame portion may be defined or described by the ceiling frame. The ceiling frame may have an upper surface. The ceiling frame may have a lower surface. The second depth may be defined between the upper and lower surfaces. The ceiling frame may comprise, and / or may be formed from or defined by, a plurality of elongate frame members. The elongate frame members may define the upper and / or the lower surfaces. The ceiling frame may comprise a perimeter frame structure, which may comprise elongate beams. The perimeter frame structure may comprise first and second side beams, which may be disposed substantially parallel to one another. The perimeter frame structure may comprise first and second end beams, which may be disposed substantially parallel to one another. The first and second side beams, and the first and second end beams, may together form or define a majority or all of the perimeter frame structure. The ceiling frame may comprise at least one support beam which may extend in a direction between the first and second end beams, and disposed between the side beams. The ceiling frame may comprise a plurality of elongate joists. At least one joist may extend in a direction between the first and second side beams. At least one joist may be arranged to have a depth which is different to (e.g. less than) a depth of beams forming the perimeter frame structure. The ceiling frame portion may comprise at least one mounting member, and may comprise a plurality of mounting members. The mounting member may serve for mounting a further (e.g. upper) modular building unit on the modular building unit. The at least one mounting member may protrude or extend from an upper surface or extent of a frame member or members forming part of the ceiling frame. The at least one mounting member may extend upwardly and / or in a generally vertical direction, optionally away from the upper surface / extent of the ceiling frame member(s). The at least one mounting member may take the form of a block, post, stub, pin or peg- The at least one mounting member, in particular an upper surface of said mounting member, may be configured to contact a lower surface of a further (e.g. upper) modular building unit stacked or seated on the modular building unit, in particular a lower surface of a floor frame of said further unit. This may provide the advantage that a void, space or gap can be formed between the two modular building units using the at least one mounting member, which may accommodate e.g. utilities such as sewerage conduits as discussed above. Said void can be created with minimal additional structure, and so cost and weight savings. The second depth may be defined between the upper surface of the mounting member(s) and a lower surface of the ceiling portion (which may be defined by the ceiling frame, in particular by lower surfaces of its elongate frame members). The at least one mounting member may be coupled to, or provided by (e.g. integral to), the ceiling frame. There may be a plurality of mounting members, which may be spaced apart around the perimeter of the modular building unit defined by the ceiling frame. A mounting member may be provided at each comer of the modular building unit, which comers may be defined by the ceiling frame. The ceiling frame portion, in particular its ceiling frame, may be configured to support a planar ceiling structure. Said planar ceiling structure may define a ceiling of the modular building unit. Said planar ceiling structure may comprise, or may be defined by, one or more planar ceiling panel. The second depth of the ceiling frame portion may not include said planar ceiling structure, other structural or insulative material connected to said planar ceiling structure, and / or any decorative finish or covering (such as a cementitious coating) applied to said planar ceiling structure. Reference is made in this document to a ceiling frame portion of the modular building unit, and to a ceiling of the unit. Reference to a ceiling frame portion (and a ceiling) should be taken to mean an upper structure which covers or encloses an internal volume of the modular building unit. It will be understood that the ceiling frame portion of the modular building unit will not typically provide a weather-resistant roof structure intended to prevent e.g. water ingress into the modular building unit. For example, a roof structure may be formed separately and positioned above the modular building unit in order to weatherproof it. However, the modular building unit could optionally provide such a roof, for example by arranging the ceiling frame portion to additionally provide or define an external or outer roof for the unit. This may be an option particularly e.g. for single storey buildings comprising the modular building unit, or where the unit forms an uppermost storey of a building. Suitable options can include a flat roof structure. The support structure may comprise at least one support post or column, and suitably comprises a plurality of support posts or columns. Support posts / columns may be provided at one or more comer of the modular building unit, in particular at one or more comer of the floor frame portion. At least one support post / column may be provided at a location on a perimeter of the floor frame portion which is spaced from one or more of the comers. The support structure may comprise bracing or support members which may extend transversely between a pair of adjacent support posts / columns. Other options for the support structure exist, including structural insulated panels (SIPs), and other panels e.g. of a cement-based material. The access function provided by the circulation space (which may also be referred to as a circulation zone or transition space / zone) may be selected from the group comprising: access between upper and lower living spaces of the building (e.g. provided by upper and lower storeys of the building), optionally via a staircase or a lift shaft and lift, provided at least partly in the modular building unit; access between a first living space and at least one further living space of the building, said living spaces optionally being isolated from one another within another part of the building and optionally on a same level / storey (e.g. via a hallway / landing and one or more doorway or walkway provided at least partly in the modular building unit); and access into the building from an exterior of the building (e.g. via one or more doorway or walkway, and optionally also a hallway, provided by the modular building unit). The circulation space may be defined wholly by the (or a) modular building unit. For example, where the circulation space provides access from the outside of the building, the space may be defined wholly by a single such unit. The circulation space may be defined in combination by a plurality of modular building units. For example, where the circulation space provides access between upper and lower living spaces, two or more units may cooperate to define the access, e.g. each may form part of a staircase or lift shaft. The at least one modular building unit may define (and suitably may completely or entirely define) at least one room, and may define a plurality of rooms. The at least one modular building unit may comprise an internal volume, and the room(s) may be defined within, and may accommodate part of, said volume. The at least one modular building unit may be arranged so that it comprises one or more wall, which may define a boundary or boundaries (optionally all boundaries) of said room. At least one room may contain a wet facility, which may be selected from the group comprising a bathroom, a shower room, an ensuite, a W / C or washroom, and a utility room. One or more further room of the plurality of rooms may be arranged to contain a wet facility. The at least one modular building unit may be arranged to define at least part of a perimeter of the building, which may be an external perimeter. The modular building unit may comprise one or more wall, and a wall or walls of the modular building unit may be arranged to define said part of the perimeter. The wall or walls may be arranged so that an external surface of the wall or walls defines an external surface of the building, or may be clad or surfaced with an exterior surface finish / coating (e.g. panels, bricks slips, cementitious render). According to a second aspect of the present invention, there is provided a modular building assembly comprising: a first modular building unit; and a second modular building unit positioned on the first modular building unit so that the second modular building unit is supported by the first modular building unit; in which the first modular building unit comprises a structural frame, the structural frame comprising: a floor frame portion having a first depth, the floor frame portion configured to support a planar floor structure; a ceiling frame portion having a second depth; and a support structure extending between and connecting the floor frame portion to the ceiling frame portion; in which a ratio of the first depth of the floor frame portion relative to the second depth of the ceiling frame portion is at least about 1:3; and in which the modular building unit defines a circulation space configured to provide at least one access function for a building comprising the modular building unit. The first modular building unit may have any of the further features set out above in relation to the first aspect. The second modular building unit may be a modular building unit according to the first aspect, and so may have any of the further features set out above. According to a third aspect of the present invention, there is provided a building comprising the modular building unit of the first aspect, or the modular building assembly of the second aspect. The building may be a hybrid building, in particular a hybrid residential building, comprising a first building section and a second building section. The first building section may be an on-site construction at a final location for the building. The second building section may be defined by and / or may comprise the modular building unit of the first aspect, or the modular building assembly of the second aspect. The first and second building sections may be configured to be connected at the final location to form the building. The building may be a modular building comprising a plurality of modular building units (at least one of which is the modular building unit according to the first aspect), or at least one (and optionally a plurality) of modular building assemblies according to the second aspect. An internal volume of the building, optionally excepting an upper or outer roof of the building, may be formed entirely by said units / assembly or assemblies. The building may comprise a foundation comprising a load bearing structure and thermal insulation. The modular building unit / assembly may be located on the foundation so that the load bearing structure provides structural support for the modular building unit / assembly, and so that the thermal insulation thermally insulates the modular building unit / assembly relative to the ground. The circulation space (which may also be referred to as a circulation zone or transition space / zone) may be arranged to provide one or more access function selected from the group comprising: access between upper and lower living spaces of the first building section (e.g. between upper and lower storeys of the section, via a staircase, or a lift shaft and lift); access between a first living space and at least one further living space of the first building section, said living spaces optionally being isolated from one another within the first building section and optionally on a same level / storey of the section (e.g. via a hallway / landing and one or more doorway or walkway); and access into the first building section from the outside of the building, and so access into the building from its exterior (e.g. via one or more doorway or walkway, and optionally also a hallway). The modular building unit may have any of the further features set out above in relation to the first aspect. According to a fourth aspect of the present invention, there is provided a method of constructing a hybrid building comprising the steps of: constructing a first building section at a final location for the building; at a location away from the final location, constructing a modular building unit according to the first aspect of the invention to a substantially assembled form; transporting the modular building unit to the final location in the substantially assembled form, and arranging the modular building unit to form at least part of a second building section of the building; and connecting the first and second building sections to form the building. The building may be a hybrid residential building. The method may comprise constructing a foundation for the building, which may comprise providing the foundation with a load bearing structure and thermal insulation. The method may comprise locating the at least one modular building unit on the foundation so that the load bearing structure of the foundation provides structural support for the modular building unit, and so that the thermal insulation of the foundation thermally insulates the modular building unit relative to the ground. The method may comprise arranging the first building section so that it is supported by the foundation. The method may comprise arranging the modular building unit so that it forms a planar floor structure of the second building section, and may comprise providing the planar floor structure with an upper support surface. The method may comprise forming the planar floor structure by positioning a planar floor panel or panels on the floor frame portion of the modular building unit, and arranging said panel so that it forms the upper support surface. The method may comprise providing the first building section with a floor, and may comprise providing the floor with an upper support surface. The method may comprise arranging the floor of the first building section so that its upper support surface is at a common or uniform height with the upper support surface of the modular building unit. The method may comprise providing the floor of the first building section with a depth equivalent to the first depth of the modular building unit plus a depth of the planar floor structure of the modular building unit. Further features of the method may be derived from the text set out elsewhere in this document, particularly in or with reference to any one or more of the first to third aspects. Reference is also made to the hybrid building and associated construction methods disclosed in International patent publication nos. WO2022 / 243696, WO2022 / 243695, WO2022 / 243694 and WO2022 / 243693, as well as International patent application no. PCT / EP2023 / 063435, the disclosures of which are incorporated herein by this reference. Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is an isometric view of a modular building unit, and a modular building assembly comprising the modular building unit, according to an embodiment of the invention; Figs. 2 and 3 are side and end views of the modular building unit, and the modular building assembly comprising the unit, shown in Fig. 1, drawn to a different scale and taken in the directions of the arrows A and B respectively; Figs. 4 and 5 are enlarged perspective views of parts of portions of a structural frame of the modular building unit; Fig. 6 is a perspective view of a hybrid building according to an embodiment of the invention, comprising the modular building unit (and the modular building assembly) of Figs. 1 and 2, shown with an external layer of the building removed; Fig. 7 is a perspective view of the hybrid building shown in Fig. 6, shown including its external layer; Figs. 8 and 9 are plan views of lower and upper storeys respectively of the hybrid building shown in Figs. 6 and 7, drawn to a different scale; Fig. 10 is a simplified wire-frame isometric view of the modular building assembly of Fig. 1, shown relative to a foundation of the building of Figs. 6 and 7; Fig. 11 is an enlarged vertical cross-sectional view of part of the foundation, and of the modular building unit, shown in Fig. 10; Figs. 12 and 13 are plan views of floor and ceiling frame portions, respectively, of the structural frame shown in Figs. 4 and 5; and Fig. 14 is a wire-frame isometric view of a plurality of modular building assemblies, configured to form part of a building according to an alternative embodiment of the invention. Turning firstly to Fig. 1, there is shown an isometric view of a modular building unit according to an embodiment of the invention, the unit illustrated generally by reference numeral 10. The modular building unit 10 is shown in the drawings with certain features removed, so that a structure of the unit can be seen. The drawing also shows a modular building assembly, indicated generally by reference numeral 12, comprising the modular building unit 10 and a further modular building unit which is indicated by numeral 14. Reference is also made to Figs. 2 and 3, which are side and end views respectively of the modular building unit 10, and the modular building assembly 12, drawn to a different scale. These drawings show structural features of the wall or face of the unit 10 / assembly 12 which can be seen in the viewing direction. The modular building unit 10 comprises a structural frame, indicated generally by numeral 16. The structural frame 16 comprises a floor frame portion 18 configured to support a planar floor structure (which will be described below), a ceiling frame portion 20, and a support structure 22 extending between and connecting the floor frame portion to the ceiling frame portion. As best shown in the enlarged perspective views of Figs. 4 and 5 (showing lower 24 and upper 26 corner regions of the structural frame 16), the floor frame portion 18 has a first depth Di, whilst the ceiling frame portion 20 has a second depth D2. A ratio of the first depth Di of the floor frame portion 18 relative to the second depth D2 of the ceiling frame portion 20 is at least about 1:3. It will be understood that the depths Di and D2 of the floor and ceiling frame portions 18 and 20 are considered or measured in a generally vertical direction. Reference may however be made to vertical heights of the floor and ceiling frame portions 18,20. Numerous options for forming the structural frame 16 exist. Preferred options include a metallic frame, which can be of a cold-formed metal or metal alloy (e.g. light gauge steel), a hot formed metal or metal alloy (e.g. hot rolled steel), or combinations of the two. A hot-formed metallic frame may provide a sufficiently rigid structure so that additional perimeter support posts and bracing struts can be dispensed with (or the number of posts / struts reduced). Other options include timber-based frames. In the illustrated embodiment however, the structural frame 16 is formed from cold-formed steel, comprising elongate members which may be of a generally hollow box shape in cross-section, or channels having a C, L or U-shape. Connection methods for structural components of the frame can include welding (metallic frames), bonding and mechanical fixations such as nut and bolt assemblies and rivets. Fig. 6 will now be referred to, which is a perspective view of a hybrid building 28 according to an embodiment of the invention, comprising the modular building unit 10 (and the modular building assembly 12) of Figs. 1 and 2. The hybrid building 10 is shown in Fig. 6 with an external layer removed so that a structure of the building can be seen. Fig. 7 is a view similar to Fig. 6, but showing the external layer 30, which in this embodiment is formed from bricks or blocks. In the illustrated embodiment, the hybrid building 28 is a house, and in particular a detached house. The principles of the invention can however apply to other types of house, including semi-detached and terraced, as well as single storey houses (bungalows). In addition, the principles of the invention can apply to other residential buildings such as flats / apartments and hotels, and indeed to non-residential buildings, e.g. industrial or commercial buildings. The hybrid building 28 comprises a first building section 36 and a second building section 38. The first building section 36 is an on-site construction at a final location 40 for the building, and is generally L-shaped in plan view (although not restricted to that shape). Part of the first building section 36 has been removed in the drawing, to show inside the section. The second building section 38 comprises the modular building unit 10, which is generally rectangular shape in plan view. The unit 10 is constructed to a substantially assembled form away from the final location 40, for example in a dedicated factory or facility. The unit 10 is transported to the final location 40 in its substantially assembled form, and arranged to form at least part of the second building section 38. In the illustrated embodiment, the second building section 38 is effectively formed by the modular building assembly 12, and so comprises both the modular building unit 10, and the further modular building unit 14. The further unit 14 is preferably a unit according to the invention, and so has similar features to the unit 10, which share the same reference numerals with the addition of the suffix '. As explained in detail in International patent publication nos. WO2022 / 243696, WO2022 / 243695, WO2022 / 243694 and WO2022 / 243693, as well as International patent application no. PCT / EP2023 / 063435, the hybrid building 28 is formed by connecting the first and second building sections 36 and 38 together at the final location 40. As can be seen from Fig. 6, the second building section 38 fits with the generally L-shaped first building section 36 in order to form a building having a generally rectangular shape in plan view. Other shapes are of course possible. The modular building unit 10 can have any suitable dimensions, with the proviso that it will generally be required to be transported e.g. by road or rail from the factory to the final location 40. The illustrated unit 10 is around 5300 to 5400mm in length, and around 2500 to 2600mm in width, which is particularly suited to such transportation. The unit 10 is smaller than many conventional modular building units, which can facilitate transportation and handling. This can also facilitate provision of the relatively thin floor described herein, and provides material, weight and cost savings. Although the illustrated unit 10 extends only part way between the front and back of the building 28, other units according to the invention may extend the full length of the building, and so may e.g. have a greater length dimension. The modular building unit 10 defines a circulation space configured to provide one or more access function for the hybrid building 28. This is best shown in Figs. 8 and 9, which are plan views of lower 32 and upper 34 storeys respectively of the hybrid building 28, drawn to a different scale. The circulation space is indicated by numeral 42, and shown in broken outline and cross-hatched in the drawings. In the illustrated embodiment, the circulation space 42 provides three access functions. One such function is access between lower 44 and upper 46 living spaces of the building 28, provided respectively by the lower and upper storeys 32, 34. This is achieved by means of a staircase 48 in the modular building unit 10 (but could be achieved e.g. via a lift shaft and lift). The living space 44 forms a lounge or sitting room, whilst the living space 46 forms a bedroom, and the circulation space 42 therefore provides access between these different living spaces. Another such function is access between a first living space and at least one further living space of the building, the living spaces being isolated from one another within another part of the building. As can be seen in Fig. 8, the first building section 36 comprises the living space 44 (lounge or sitting room), and a further living space 50, which forms an open plan kitchen-dining room. The circulation space 42 provides access between these living spaces 44 and 50, by means of walkway openings 52, 54 and a hallway 55. It will be noted here that the precise configuration of walkway openings shown in Figs. 8 and 9 are slightly different to those shown in the drawing Figs. 1 to 3 of the unit 10. This illustrates alternative possible positions for the openings. The circulation space 42 additionally provides access between the lower living space 44 (and also the space 50) and the upper living space 46, which are effectively isolated from one another within the first building section 36. Also, further living spaces 56 and 58 (also bedrooms) are provided in the upper storey 34 of the first building section 36, and the circulation space 42 provides access both between these further living spaces 56 and 58, and between the lower living spaces 44 / 50 and these further living spaces. Another such function is access into the building 28 from an exterior 60 of the building, via a doorway or walkway 62 of the unit 10, which in this case forms a front doorway for the building. The doorway 62 opens on to the hallway 55 to provide access to the staircase 48 (for access to upper living spaces 46, 56 and 58), and the internal walkways 52 and 54 (for access to the lower living spaces 44 and 50). Whilst the illustrated modular building unit 10 comprises a circulation space 42 which provides all three access functions described above, it will be understood that variations may provide only one or only some of the stated functions. The provision of a modular building unit 10 having the depth relationship between its structural frame floor and ceiling portions 18 and 20 (which effectively requires that D2> 3Di) may provide particular benefits in the context of the hybrid building 28 described above. This includes facilitating matching a floor level of the second building section 38 with a floor level of the first section 36 constructed at the final location 40. In particular, the first and second building sections 36 and 38 may rest on a common foundation. This is shown in Fig. 10, which is a simplified wire-frame isometric view of the modular building assembly 12 of Fig. 1, shown relative to a foundation 64 of the building 28. The foundation 64 supports both the second building section 38 (defined by the modular building assembly 12), and the first building section 36, which has been omitted from the drawing. It can be desirable to maintain common (or uniform) floor levels within the constructed building 28, to avoid a change in floor height between the building sections 36 and 38. Providing the modular building unit structural frame 16 with floor 18 and ceiling 20 frame portions having the stated depth relationship may have the result that the floor frame portion depth Di can be relatively shallow, so that only a small height difference need be accommodated by the first building section 36. This may provide benefits in terms of material and cost savings. In addition, arranging the floor 18 and ceiling 20 frame portions so that they have depths Di and D2 in the stated ratio may have the result that the ceiling frame portion can be relatively deep, without adversely impacting the depth of the floor frame portion. This may enable the ceiling frame portion 20 to provide a majority of the structural strength for the modular building unit 10, and space to accommodate utilities e.g. servicing the upper modular building unit 14, which is stacked on the (lower) unit 10. The utilities could include wastewater conduits for wet facilities provided in the upper modular building unit 14, water supply conduits, ventilation conduits, and electrical power and communication cables, amongst other things. The shallow floor frame portion may also help to reduce a depth Da (Fig. 5) of structure at the intersection between the ceiling portion 20 of the (lower) modular building unit 10, and a floor portion 18' of the upper unit 14. The ratio of the first depth Di of the structural frame floor portion 18 relative to the second depth Da of the frame ceiling portion 20 may be up to about 1:6, and may be in a range of between about 1:3 to about 1:6. A ratio falling within this range may provide a good balance of a relatively thin floor portion 18, and a ceiling portion 20 that can provide a majority of the structural strength for the modular building unit 10, and / or space to accommodate required utilities. The first depth Di of the floor frame portion 18 may be up to about 70mm (—2.756”). A floor frame portion 18 having such a depth may be relatively shallow, and may be significantly shallower than floor frame portions of conventional modular building units. Fig. 11 is referred to, which is an enlarged vertical cross-sectional view of part of the foundation, and of the modular building unit 10, shown in Fig. 10. The foundation 64 is an insulated foundation, comprising a load bearing structure 68 and thermal insulation 70. The modular building unit 10 is located on the foundation 64 so that the load bearing structure 68 provides structural support for the unit, and so that the thermal insulation 70 thermally insulates the modular unit relative to the ground 72. As shown in Fig. 11, a level of a floor 74 of the first building section 36 may be brought up to that of the floor frame portion 18 of the modular building unit 10 (forming part of the second building section 38) by applying e.g. a cementitious screed 76 to a floor support structure of the first section, in this case the foundation load bearing structure 68. It may be preferred to restrict the first depth Di of the floor frame portion 18 to no more than around 70mm, which may be a maximum optimal height for the screed 76. However, in a particularly preferred option, the first depth Di may be up to around 50mm (~1.968”), although generally a depth in a range of about 50mm to about 70mm may be suitable. Numerous options for forming the thermal insulation 70 exist, including constructing it from a series of shaped blocks (not shown) of a suitable insulating material which can bear the load of the completed building 10. Examples include Isoquick® insulation blocks commercially available in the UK from Build Homes Better Ltd, which can be arranged to form an insulation raft or pad. The blocks are formed from a water-resistant polymeric foam material, in particular Peripor® available from BASF SE. The blocks forming the thermal insulation 64 are typically arranged in two interlocking layers 70a / b, with interlocking features (not shown) such as protrusions and recesses provided at an interface between the layers. The thermal insulation 70 provides a surface 78 on which the load bearing structure 68 can be positioned, and in the illustrated embodiment, provides a substantially continuous surface. The load bearing structure 68 is located on the surface 78 following positioning of the thermal insulation 70 on the ground 72. The load bearing structure 68 is insulated relative to the ground 72 by the thermal insulation 70, so that thermal energy transfer between the load bearing structure and the ground is resisted. This in turn insulates the modular building unit 10 (located on the foundation 64) relative to the ground 72, reducing / preventing thermal bridging between the unit and the ground. The load bearing structure 68 can take the form of a layer of reinforced concrete, which can be formed at the final location 40 for the building in a conventional fashion. Moisture barrier layers (not shown) can be positioned below the thermal insulation 70, and between the upper surface 78 of the thermal insulation and a lower surface of the load bearing structure 68. The moisture barriers may take any suitable form known in the field of the invention. Particularly suitable options may include: a moisture resistant sheet, which may be a substantially impermeable membrane e.g. of a polymeric material such as polyethylene. In a variation for, the foundation 64 may be formed by positioning the load bearing structure 68 on or in the ground 72, with the thermal insulation 70 positioned on the load bearing structure and supporting the modular building unit 10 (and the first building section 36). It will be understood that the thermal insulation will then be required to have sufficient load bearing capacity to bear structural loads imparted upon it by the modular building unit 10, and indeed by a remainder of the building 28. In a further variation, the load bearing structure may be formed from pre-cast blocks or beams (not shown). The second depth D2 of the ceiling frame portion 20 may be at least about 150mm (—5.906”), and in embodiments, may be up to about 300mm (-11.811”). The second depth D2 may therefore be in a range of about 150mm to about 300mm. A depth in the region of about 250mm may however be preferred. A modular building unit having such floor 18 and ceiling 20 frame portion first and second depths Di and D2 may provide a good balance of benefits, e.g. in terms of minimising disruption (during construction of the first building section 36) to accommodate the floor frame portion 18 and / or minimising a depth of structure at a transition between the lower 10 and upper 14 modular building units, whilst providing a sufficiently strong ceiling frame portion 20 and / or depth in the ceiling frame to accommodate utilities. As mentioned above, the upper modular building unit 14 is a unit according to the invention. The unit 14 thus comprises a structural frame 16' having the floor frame portion 18', a ceiling frame portion 20', and a support structure 22'. The depth D3 of the structure at the intersection between the lower unit ceiling portion 20 and the upper unit floor portion 18' is typically in the range of 200mm to 300mm, bearing in mind the optional depth ranges for Di and D2 discussed above. This can be particularly beneficial in terms of material savings, and reducing complexity of a transition for the staircase 48 as it passes between the two units 10, 14. The upper unit 14 is mounted on the lower unit 10 at the final location 40, following location of the lower unit on the foundation 64. Further details of the structure of the modular building unit 10 will now be described, with reference also to Figs. 12 and 13, which are plan views of just the floor and ceiling frame portions 18 and 20, respectively. The floor frame portion 18 comprises a floor frame 80, which defines the first depth Di. The floor frame 80 has an upper surface 82 and a lower surface 84 (Figs. 2 and 4), and the first depth Di is defined between these upper and lower surfaces. The floor frame 80 is formed from a plurality of elongate frame members which define the upper and lower surfaces 82, 84. In the illustrated embodiment, the floor frame 80 comprises a perimeter frame structure 86, which comprises elongate beams, specifically first and second side beams 88 and 90 disposed substantially parallel to one another, and first and second end beams 92 and 94 disposed substantially parallel to one another. A support beam 96 also extends in a direction between the first and second end beams 92 and 94, and is disposed between the side beams 88 and 90. The support beam 96 provides additional structural rigidity, and can support internal wall structures in the modular building unit 10. The floor frame 80 also comprises a plurality of elongate joists, which extend in a direction between the first and second side beams 88 and 90. First and second sets of joists (indicated respectively by numerals 98 and 100) extend between the side beam 90 and the support beam 96. A third set of joists (indicated by numeral 102) extend between the side beam 88 and the support beam 96. Typically, the joists in the sets 98-102 are of the same depth (Di) as the beams in the perimeter frame 86, but at least some could be arranged to have a depth which is different to (e.g. less than) the depth of beams forming the perimeter frame. The floor frame 80 is configured to support a planar floor structure 104, which is shown in Figs. 4 and 11. The planar floor structure 104 defines a floor of the modular building unit 10, and is defined by one or more planar floor panel (one shown and given the numeral 106). Many options for forming the floor structure 104 exist, but preferred options include timber-based materials for the panel 106, such as chipboard, fibreboard and plywood. The first depth Di of the floor frame portion 18 does not include the planar floor structure 104, or indeed other structural or insulative material positioned on said floor structure, and / or any decorative floor finish or covering (such as carpet or tiles) positioned on said floor structure. As explained above, the screed 76 forming the floor 74 of the first building section 36 typically has the same depth Di as the floor frame portion 18 (and so the frame 80). The floor 74 may be brought up to the level of that provided by the module planar floor structure 104 by positioning a further floor structure 108 on the screed floor 74. This could again be e.g. panel based and of a timber material, to provide uniformity across the building sections 36, 38. It will be understood though that various other options exist, including that the screed 74 could be arranged to have an upper surface which matches that provided by the module planar floor structure 104. The ceiling frame portion 20 comprises a ceiling frame 110, which defines the second depth D2. The ceiling frame 110 has an upper surface 112 and a lower surface 114, and the second depth D2 is defined between these surfaces. The ceiling frame 110 is formed from a plurality of elongate frame members which define the upper and lower surfaces 112, 114. The ceiling frame 110 comprises a perimeter frame structure 116, which comprises first and second side beams 118 and 120 disposed substantially parallel to one another, and first and second end beams 122 and 124 disposed substantially parallel to one another. A support beam 126 also extends in a direction between the first and second end beams 122 and 124, and is disposed between the side beams 118 and 120. As for the floor support beam 96, this support beam 126 provides additional structural rigidity and can support internal wall structures in the modular building unit 10. The ceiling frame 110 also comprises a plurality of elongate joists, which extend in a direction between the first and second side beams 118 and 120. First and second sets of joists (indicated respectively by numerals 128 and 130) extend between the side beam 116 and the support beam 126. Third and fourth sets of joists (indicated respectively by numerals 132 and 134) extend between the side beam 118 and the support beam 126. Typically, the joists in the sets 128-134 have a depth which is less than the depth (D2) of the beams in the perimeter frame 116, but at least some could be of the same depth. The ceiling frame portion 20 also comprises at least one mounting member, which serves for mounting the further (upper) modular building unit 14 on the modular building unit 10. In the illustrated embodiment, the ceiling frame portion 20 comprises a plurality of mounting members 136a-d, each positioned at comers of the ceiling frame 110. Further mounting members 136e-h are positioned along the end beams 122,124 and side beams 118 and 120 spaced from the relevant comer mounting members. The mounting members 136a-h protmde or extend from an upper surface or extent of the beams forming the ceiling frame 110, indicated at 138 in Fig. 5. The mounting members 136a-h extend in a generally vertical direction, away from the upper surface 138, and suitably take the form of a block, post, stub, pin or peg. Upper surfaces of the mounting members 136a-h are configured to contact a lower surface of the further (upper) modular building unit 14, which is stacked or seated on the modular building unit 10 and connected to the mounting members. Referring to Fig. 5 showing the mounting member 136c, the mounting member defines the upper surface 112 discussed above, which abuts a lower surface 140 of a floor frame of said further unit (defined by its side frame member 18'). This may provide the advantage that a void, space or gap 142 is formed between the two modular building units 10 and 14, which can accommodate e.g. utilities, such as sewerage conduits as discussed above. The conduits are shown in broken outline in Fig. 2, and indicated generally by numeral 144. These conduits 144 may connect to wet facilities in the upper modular building unit 14, which will be described below, and may ultimately pass through a service module 146 in the unit 10 to a sewer (not shown). The void 142 can be created with minimal additional structure, and so affords cost and weight savings. The second depth D2 of the ceiling frame portion 20 is defined between the upper surfaces 112 of the mounting members 136a-h and the lower surface 114 of the ceiling portion (defined by the ceiling frame 110, in particular by lower surfaces of its frame members). The mounting members 136a-h are typically coupled to, or provided by (e.g. integral to), the ceiling frame 110. The upper modular building unit 14 is connected to the lower unit 10 to form the assembly 12, in order to resist particularly lateral movement of the units relative to one another. Various options exist for connecting the units 10 and 14, including welding, bonding and mechanical fixings. Suitable mechanical fixings can include nut and bolt assemblies, pins and locating sockets and the like. The ceiling frame portion 20, in particular its ceiling frame 110, is configured to support a planar ceiling or ceiling structure 148, which is shown in Fig 5. The planar ceiling structure 148 defines a ceiling of the modular building unit 10, and is defined by one or more planar ceiling panel (one shown and given the numeral 150). Many options for forming the ceiling structure 148 exist, but preferred options include plasterboard panels or sheets. The second depth D2 of the ceiling frame portion 20 does not include the planar ceiling structure 148, other structural or insulative material connected to said planar ceiling structure, and / or any decorative finish or covering (such as a plaster render). Reference is made in this document to a ceiling frame portion of the modular building unit 10, and to a ceiling of the unit. Reference to a ceiling frame portion 20 (and a ceiling) should be taken to mean an upper structure which covers or encloses an internal volume of the modular building unit 10. It will be understood that the ceiling frame portion 20 of the modular building unit 10 will not typically provide a weather-resistant roof structure intended to prevent e.g. water ingress into the modular building unit. To this end, and referring to Fig. 6, a separate roof structure 150 is shown which is constructed e.g. from a plurality of roof trusses 152. The roof structure 150 bridges across the first and second building sections 36 and 38, and weatherproofs the building 28. However, the modular building unit 10 could optionally provide such a roof, for example by arranging the ceiling frame portion to additionally provide or define an external or outer roof for the unit. This may be an option particularly e.g. for single storey buildings comprising the modular building unit, or where the unit forms an uppermost storey of a building. Suitable options can include a flat roof structure. In the light gauge steel frame (LGSF) structural frame 16 shown in the drawings, the support structure 22 is relatively complex, and will not be described in detail. In brief however, the support structure 22 comprises a plurality of support posts or columns 154a-c (Fig. 1), each provided at a comer of the frame 16, extending between and connected to the floor and ceiling frame portions 18, 20. Further support posts or columns are provided at locations on a perimeter of the floor frame portion 18 which are spaced from one or more of the comers. Numerous such further support posts are referred to, and given the numerals 154d-k. To ease construction, the various support posts 154a-k are each connected at one end to a floor mounting member, and at a second opposite end to a ceiling mounting member, to form wall structures that can be connected to the floor and ceiling portions 18, 20. Fig. 1 shows an internal face or wall 155 of the unit 10 defined by the support structure 22. A floor mounting member 157 is mounted on the floor side beam 88, and a ceiling mounting member 159 is mounted to the ceiling side beam 118. The support posts 154b, 154d and 154g-k shown in the drawing are connected between the floor and ceiling mounting members 157 and 59, so that they extend between (and support) the floor and ceiling portions 18, 20 in the assembled unit 10. It will be noted that the floor mounting members in particular do not extend across parts of the unit 10 perimeter frame structure 116 which provide doorways or walkways for accessing the first building section 36. See for example at the walkway 52 providing access to the open plan room 50. This is to provide the uniform floor level between the first and second building sections 36 and 38 discussed above with reference to Fig. 11. The support structure 22 also comprises transverse bracing or support members. A plurality of bracing members (one indicated with the numeral 156) extend between pairs of adjacent support posts / columns 154, in a direction generally perpendicular to the support posts. Diagonal bracing members (one indicated with numeral 158) extend between some of the support posts 154 and the floor or ceiling frame portions 18, 20. Other options for the support structure 22 exist, including structural insulated panels (SIPs), and other panels e.g. of a cement-based material. As can be seen in Figs. 8 and 9, the modular building unit 10 defines a plurality of rooms within the building 28, at least some of which provide wet facilities in the form of a W / C or washroom 160, and a utility room 162. The unit 10 is arranged so that it comprises internal walls which define a boundary or boundaries of the washroom 160 and utility room 162. Referring for example to the washroom 160, the unit 10 includes internal walls 162 to 166 which define a space that forms the washroom. The washroom 160 is accessed from the hallway 55 of the circulation space 142, whilst the utility room is accessed directly from the open plan room 50. In a similar fashion, the upper modular building unit 14 comprises rooms providing wet facilities in the form of a bathroom 168 which is accessed via a landing 172 of the circulation space 42, and an ensuite 170 which is accessed from the bedroom 58. As explained above, sewerage conduits 144 connecting to washing and toilet facilities in the bathroom 168 and the ensuite 170 can be accommodated at least partly in the void 142 between the units 14 and 10. This can include, for example, sewerage connections for a toilet 174, bath 176 and sink 178 in the bathroom 168. In the illustrated building 28, the modular building units 10 and 14 are enclosed within the external brick layer 30. Walls of the units 10 and 14 are formed by connecting wall panels or sheets to the structural support frames 16 and 16’ (in particular to supports posts and bracing members). For example, and as shown in Fig. 6, panels 180-184 can form an external wall 186 of the modular unit 10. The modular building units 10, 14 can however be arranged to define at least part of a perimeter of the building, in particular an external perimeter. This can be achieved by arranging the panels 180-184 as external cladding panels. In a variation on the illustrated embodiment, the building 28 may be a modular building comprising a plurality of modular building units which form all (or at least a majority) of an internal volume of the building. This is illustrated in Fig. 14, which is a wire-frame isometric view of a plurality of modular building assemblies, configured to form part of a building 28". Like components of the building 28" with the building 28 share the same reference numerals, with the addition of the suffix ". The building 28" comprises a plurality of modular building units, at least one of which is a modular building unit according to the invention. In a particularly preferred option, all of the modular building units are units according to the invention. The modular building units are arranged in assemblies stacked as discussed above in relation to the modular building assembly 12. Thus a modular building assembly 12" comprises a lower modular building unit 10" and an upper modular building unit 14" stacked on the lower unit. A further modular building assembly 12a" similarly comprises a lower modular building unit 10a” and an upper modular building unit 14a" stacked on the lower unit. Between them, the modular building units of the assemblies 12" and 12a" define the entire internal volume of the building 28", with the exception of an upper or outer roof of the building (not shown), which may be formed at a final location for the building (as for the roof structure 150), or formed as a modular (transportable) structure. Various modifications may be made to the foregoing without departing from the spirit or scope of the present invention. Further aspects and / or embodiments of the invention may combine the features of one or more aspect and / or embodiment disclosed in this document. Accordingly, such further aspects and / or embodiments may comprise one or more feature selected from one or more aspect or embodiment of the invention disclosed in this document. Unless explicitly implied by context or stated in the document, the features of any method or process disclosed in this document need not necessarily be performed in the precise order set out in the relevant text and / or drawings. Accordingly, any method or process disclosed in this document may be capable of being performed in an order other than that specifically set out in the relevant text / drawings, if circumstances permit. Features disclosed in this document (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Accordingly, features disclosed in this document may represent only one example of a generic series of equivalent or similar features. 26 08 25

Claims

1. A modular building assembly comprising:5 a first modular building unit; anda second modular building unit positioned on the first modular building unit so that the second modular building unit is supported by the first modular building unit;in which the first modular building unit comprises a structural frame, the structural frame comprising:a floor frame portion having a first depth, the floor frame portion configured to support a10 planar floor structure;a ceiling frame portion having a second depth; anda support structure extending between and connecting the floor frame portion to the ceiling frame portion;in which a ratio of the first depth of the floor frame portion relative to the second depth of the15 ceiling frame portion is at least about 1:3;and in which the modular building unit defines a circulation space configured to provide at least one access function for a building comprising the modular building unit.

2. A modular building assembly as claimed in claim 1, wherein the ratio of the first depth relative to the20 second depth is up to about 1:6.

3. A modular building assembly as claimed in claim lor 2, in which the first depth of the floor frame portion is up to around 70mm (-2.756”).25 4. A modular building assembly as claimed in claim 1 or 2, in which the first depth of the floor frameportion is up to around 50mm (-1.968”).

5. A modular building assembly as claimed in claim 1 or 2, in which the first depth of the floor frame portion is in a range of about 50mm to about 70mm.

306. A modular building assembly as claimed in any preceding claim, in which the second depth of the ceiling frame portion is at least about 150mm (-5.906”).

7. A modular building assembly as claimed in any preceding claim, in which the second depth of the35 ceiling frame portion is up to about 300mm (-11.811”).

8. A modular building assembly as claimed in any preceding claim, in which the floor frame portion comprises a floor frame, and in which the first depth of the floor frame portion is defined by the floor frame.26 08 259. A modular building assembly as claimed in claim 8, in which the floor frame has an upper surface and a lower surface, and in which the first depth is defined between the upper and lower surfaces.

10. A modular building assembly as claimed in claim 9, in which the floor frame is defined by a plurality 5 of elongate frame members which define the upper and lower surfaces.

11. A modular building assembly as claimed in any one of claims 8 to 10, in which the floor frame comprises a perimeter frame structure comprising elongate beams of the first depth.10 12. A modular building assembly as claimed in any preceding claim, further comprising the planar floorstructure, in which the planar floor structure defines a floor of the first modular building unit, and in which the first depth of the floor frame portion does not include the planar floor structure.

13. A modular building assembly as claimed in any preceding claim, in which the ceiling frame portion 15 comprises a ceiling frame, and in which the second depth of the ceiling frame portion is defined by the ceiling frame.

14. A modular building assembly as claimed in claim 13, in which the ceiling frame has an upper surface and a lower surface, and in which the second depth is defined between the upper and lower surfaces.2015. A modular building assembly as claimed in claim 14, in which the ceiling frame is defined by a plurality of elongate frame members of the second depth.

16. A modular building assembly as claimed in any one of claims 13 to 15, in which the ceiling frame 25 comprises a perimeter frame structure comprising elongate beams of the second depth.

17. A modular building assembly as claimed in any one of claims 13 to 16, comprising a plurality of mounting members which serve for mounting a further modular building unit on the modular building unit, the mounting members protruding from an upper surface of a frame member or members forming part of the ceiling 30 frame, and in which upper surfaces of the mounting members are configured to contact a lower surface of the further modular building unit to form a void between the modular building units.

18. A modular building assembly as claimed in claim 17, in which the second depth is defined between the upper surfaces of the mounting members and a lower surface of the ceiling portion.3519. A modular building assembly as claimed in any preceding claim, in which said access function is selected from the group comprising: access between upper and lower living spaces of the building; access between a first living space and at least one further living space of the building, said living spaces being isolated from one another within another part of the building; and access into the building from its exterior.26 08 2520. A modular building assembly as claimed in any preceding claim, in which the first modular building unit defines at least one room, and comprises one or more wall which boundaries of said room.

21. A modular building assembly as claimed in claim 20, in which at least one room contains a wet facility, 5 said room selected from the group comprising a bathroom, a shower room, an ensuite, a W / C or washroom, and a utility room.

22. A modular building assembly as claimed in any preceding claim, in which the first modular building unit is configured to define at least part of an external perimeter of the building.1023. A modular building assembly as claimed in any preceding claim, in which the second modular building unit comprises a structural frame, the structural frame comprising:a floor frame portion having a first depth, the floor frame portion configured to support a planar floor structure;15 a ceiling frame portion having a second depth; anda support structure extending between and connecting the floor frame portion to the ceiling frame portion;in which a ratio of the first depth of the floor frame portion relative to the second depth of the ceiling frame portion is at least about 1:3;20 and in which the modular building unit defines a circulation space configured to provide at least oneaccess function for a building comprising the modular building unit.

24. A building comprising the modular building assembly of any one of claims 1 to 23.25 25. A building as claimed in claim 24, in which the building is a hybrid residential building comprising afirst building section and a second building section, and in which: the first building section is an on-site construction at a final location for the building; the second building section is defined by the modular building assembly; and the first and second building sections are connected at the final location to form the building.30 26. A building comprising the modular building assembly according to any one of claims 1 to 23, in whichan internal volume of the building is formed substantially entirely by the units of the modular building assembly.

27. A building as claimed in any one of claims 24 to 26, comprising a foundation comprising a load35 bearing structure and thermal insulation, in which the modular building unit is located on the foundation so that the load bearing structure provides structural support for the modular building unit, and so that the thermal insulation thermally insulates the modular building unit relative to the ground.

28. A building as claimed in any one of claims 24 to 27, in which the circulation space is arranged to40 provide one or more access function selected from the group comprising: access between upper and lower living26 08 25spaces of the first building section; access between a first living space and at least one further living space of the first building section, said living spaces being isolated from one another within the first building section; and access into the first building section from the outside of the building.5 29. A method of constructing a hybrid building comprising the steps of:constructing a first building section at a final location for the building;at a location away from the final location, constructing a first modular building unit and a second modular building unit of a modular building assembly according to any one of claims 1 to 23 to a substantially assembled form;10 transporting the first modular building unit and the second modular building to the final location in thesubstantially assembled form, and arranging the first modular building unit and the second modular building unit to form at least part of a second building section of the building, the arranging comprising positioning the second modular building unit on the first modular building unit so that the second modular building unit is supported by the first modular building unit; and15 connecting the first and second building sections to form the building.

30. A method as claimed in claim 29, comprising:constructing a foundation for the building, including providing the foundation with a load bearing structure and thermal insulation;20 locating the first modular building unit on the foundation so that the load bearing structure of thefoundation provides structural support for the first modular building unit, and so that the thermal insulation of the foundation thermally insulates the first modular building unit relative to the ground; andarranging the first building section so that it is supported by the foundation.25 31. A method as claimed in either of claims 29 or 30, comprising:arranging the first modular building unit so that it forms a planar floor structure of the second building section, including providing the planar floor structure with an upper support surface;providing the first building section with a floor, including providing the floor with an upper support surface;30 arranging the floor of the first building section so that its upper support surface is at a uniform heightwith the upper support surface of the first modular building unit.

32. A method as claimed in claim 31, comprising providing the floor of the first building section with a depth equivalent to the first depth of the first modular building unit plus a depth of the planar floor structure of35 the first modular building unit.

Images