What was tested
G4 commissioned the University of Salford’s Energy House Labs to independently assess the Partner House prototype in its real-world setting. The house was tested as a whole, using full co-heating analysis, in-situ U-value measurements, thermography, air leak smoke detection and airtightness testing.
The Partner House was a live, evolving prototype. Over several years the Green 4 architectural and engineering teams introduced, assessed and refined different products, systems and technologies on it, so it was never built as a dedicated test house. That made it a demanding subject, and an honest one.
What the tests found
The prototype achieved highly energy-efficient absolute performance and the second-lowest normalised heat transfer coefficient among the on-site constructed dwellings in the Energy House Labs comparison sample. Testing also identified a performance gap against the prototype’s original, highly ambitious SAP prediction, with the roof and selected junctions making the largest contribution to the gap.
What changed as a result
G4 used the evidence to revise the roof, structural interfaces, openings, airtightness details and design assumptions for the production system. The redesigned specification is calculated at 106 W/K heat transfer coefficient and 0.83 W/m²K heat loss parameter, compared with 118.6 W/K and 0.93 W/m²K for the equivalent Future Homes Standard notional dwelling.
In other words, the system the group is now building is better than the one that was measured, and its design now rests on measured evidence rather than prediction alone.
Why it matters
Most new homes are never tested, so performance gaps can go unnoticed. Testing provides the evidence needed to improve design, validate outcomes and deliver better homes. G4’s intent is to support affordable housing providers and public-sector clients with an advanced housing system that can contribute to the UK’s ambition of 300,000 homes a year, while helping to reduce fuel poverty, through homes that demonstrably deliver high performance and long-term value.
See the evidence on the duoKore® page
