The Plimsoll House takes its name from the imaginary line marking the level at which a boat floats in the water. The design responds to the needs of climate change, and specifically the challenge of building in high-risk flood-prone areas by having a special foundation system. The foundation system is actually a buoyancy device that allows the house to rise and fall with changes in water level.

The house itself has a cellular reinforced pulped cardboard frame, which creates a series of zones into which accommodation is slotted. The box structure is capped with a sweeping 15-degree sedum roof with integrated photovoltaic cells and Velux roof lights. The fall of the roof envelops the internal spaces, creating a top lit series of rooms and circulation zones.

The four-bed house is constructed over three levels, including roof space. The house is orientated with its longest façade facing south to maximise solar gain. Services areas of the house (bathrooms and kitchen) are sited on the rear or north façade, and in the same plan vertically for maximum build efficiency.

At ground floor level, the house has a generous kitchen and dining area within a double-height balconied living space. Large areas are set aside for storage. Internal space is made flexible using a series of demountable partitions in conjunction with a structural grid. Future expansion can also be accommodated.

The designer has set a target of ten days to erect the foundations and sub-frame of the house. This is achieved through the use of a collapsible core frame, delivered to site on a flat-bed truck and anchored by four securing posts, which allows the structure to respond to varying water levels once the house is constructed.

Offsite manufactured components are used, ranging from pod bathrooms to fully-serviced internal walls. The house is built using such sustainable materials as: timber frame, sub-steel frame, FSC-approved timber cladding; pad foundations with floating ground floor replacing concrete slab, FSC-approved timber flooring, and rubber flooring.

In summary, the house seeks to address the challenges of climate change and summer overheating by:

• doubling the thermal efficiency of the roof and north elevation
• having heavyweight thermal ceilings/floors in a lightweight structural system
• its floating structure
• having minimal carbon footprint, in manufacture and use
• having low embodied energy in its materials
• being built using an efficient component system, which allows the external envelope to be replaced and recycled
• using voids, which integrate with ‘air scopes’ in the roof that allow natural cross-ventilation to all rooms by extracting rising heat from the ground floor.

© British Homes Awards |  Site design: LW design