Upton Square Northamptonshire are the first homes to be completed and certified to level 6 of the code for sustainable homes. Their energy consumption is balanced out by microgeneration which is integrated into the buildings. They were constructed using Bill Dunster' s RuralZED system which uses a low embodied energy glulam frame, developed by MLDE to support thermally massive walls and floors. The buildings utilise a single glazed sunspace as a thermal buffer zone.

RuralZED is available with a pallet of external finishes, ranging from green roofs clad in sedum mat, for good attenuation of rainfall run off - and maximising wildlife habitat or metal roofing for collecting rainfall; local timber weather-boarding and high performance timber windows or natural lime render.

Different designs are available, for east / west facing sites, or for southerly aspects. The house types can be either grouped or detached to create small urban blocks to complement existing street patterns or as urban extensions to country towns.

RuralZED Key Features:

- use of MMC: quick erection process, lower cost / cleaner construction / economy of materials
- secured supply chain certification (eg use of FSC certified materials)
- off site machined for a high level of accuracy in construction.
- The building is wrapped in 300 mm of rockwool insulation to achieve U values of circa 0.1 W/m20C, by providing a superinsulated, highly airtight envelope the ZED home minimises heat loss.
- Prefabricated high density panels are mounted between the timber superstructure, providing thermal mass on the inside of the insulated envelope.
- ZED standards achieve 2 air changes /hr @ 50 pa air pressure.
- With a southerly aspect and the incorporation of sunspaces, it is possible to build solar homes that maximise the use of passive solar design to such an extent that no extra heating system is required.