A storage cabinet (16) is provided for an ultra-low temperature freezer (10). The cabinet (16) includes a base platform (62a), a plurality of side structural insulated panels (45, 50, 55) each defining a side wall of the storage cabinet (16), and a plurality of generally vertically oriented posts (40) extending from the base platform (62a). Each of the plurality of vertically oriented posts (40) has a slot (40a) for receiving an edge portion (45a, 50a, 55a) of one of the insulated panels (45, 50, 55) therealong. The slot (40a) may have a generally U-shaped profile that surrounds the edge portion (45a, 50a, 55a) of one of the insulated panels (45, 50, 55). At least one of the generally vertically oriented posts (40) has a channel (40c) that extends along a longitudinal dimension thereof, the channel (40c) being configured to receive one of insulation, tubing, or wiring of the freezer therethrough.