Lamella gridshell design based on a sycamore seed
After Suffolk District Council recently granted planning permission for Jerry Tate’s gridshell house in Easton, Footprint brings you more detail on the sustainable design of the scheme.
A driving principle in Jerry Tate Architects’ approach to the project is integration of the 500m2 residence with the surrounding landscape. According to the architect, the building form reflects the natural proportions and geometries of a sycamore seed. The country house typology has historically had an economic and productive relationship with the countryside, though this has generally been approached as a formal or picturesque composition. With the Easton project, Tate adapts that typology to the 21st century, using existing site ecology to create a new paradigm for remote rural residences.
Based on permaculture principles, the house aims to be completely self-sufficient in terms of water, energy and most food requirements. The only infrastructure connection will be to deliver any excess electricity back to the grid once the on-site storage capacity has been filled.
The client, previously a scientist for the Ministry of Defence, has developed an innovative form of heliocentric solar collector which will provide both electricity and hot water through a reflective parabolic dish focusing the sun’s energy on a single point to concentrate the energy harvest.
His calculations show that six of these dishes, installed on this house as a prototype, will provide all electricity, hot water and heating demands for the scheme. Any excess heat will be stored underground through an interseasonal heat transfer system, which uses a ground source heat pump to extract the heat in winter. Excess electricity will be stored in a recycled battery bank, with electricity generated beyond this storage capacity fed back to the grid.
The building fabric consists of a high performance envelope to minimise heat loss, assist with solar gain in the winter months and minimise overheating during summer. The Passivhaus Planning Package was used during envelope design, and all living areas will require below 15 kWh/(m2a) for space heating.
The house will incorporate a number of features which are in keeping with a low carbon lifestyle, including a home office, bicycle storage, a drying space, composting and recycling facilities.
Smart meters will enable occupants to monitor energy use and a ‘smart switch’ will ensure that all non-essential appliances are switched off when the house is not occupied.
Water is integral to the design of the building and landscape, with a new system of ponds and reed-beds integrated into the landscape design. Captured rainwater will be recycled and stored in underground tanks and exposed attenuation ponds. This greywater will then be used within the house for toilet flushing, and as a potable supply after passing through a UV filter and for garden irrigation.
Blackwater waste will be processed in a reed bed to the south of the development which will break down all waste through bio-digestion before releasing some water into the existing stormwater system and a new soakaway.
All heavy masonry materials in the scheme will be locally sourced. Flint cladding and clay will be sourced directly on the site, and bricks will be supplied by a local brickmakers. Concrete, where used, will be mixed with recycled aggregate and 70% cement replacement with ground blast furnace slag.
Walls will be constructed from ‘Hemcrete’ with a U-value of 0.15m2k. All timber will be FSC-certified..
Super-insulated roof panels will be pre-fabricated to minimise on site waste and will achieve a U-values of approximately 0.12m2k. Windows will be triple-glazed, timber-framed with low-E coating and argon-filled cavities with a U-value of 0.7m2k.
Construction is expected to start in spring 2013.
Lead Architect: Jerry Tate Architects
Landscape Architect: Luke Greysmith
Planning Consultants: Land Use Consultants
Ecology Consultants: Applied Ecology
Arboricultural Consultants: Hayden’s