The Kingspan TEK Building System has provided an offsite building solution for one of the country’s largest Passivhaus developments in Bowthorpe, Norwich.
Rayne Park is the first development by Norwich Regeneration Company, wholly owned by Norwich City Council, and is said to include a mixture of private and affordable housing. RG Carter constructed 112 of the 172 properties on the development to the Passivhaus Standard.
Kingspan TEK structural insulated panels (SIPs) are said to feature a high-performance insulation core sandwiched between two layers of OSB/3. The panels were fabricated to the site’s requirements by Kingspan TEK Delivery Partner, Kingspan Timber Solutions. This offsite fabrication process allowed the panels to be factory cut to the specific design requirements, minimising waste and allowing an accurate, fast-track erection process on site.
Kingspan TEK Building System panels can reportedly achieve U-values of 0.20 – 0.17 W/m2.K, or better ‘out of the box’. With the addition of an additional layer of insulation, the site team were able to further improve the thermal performance of the external walls – achieving a final external wall U-value as low as 0.09 W/m2.K.
Once the outer shell was erected, RG Carter installed an additional internal membrane and applied airtight tape to all joints, resulting in a final air leakage rate of from 0.37 to 0.56 air changes per hour @ 50 Pa. This highly airtight design necessitates the use of a mechanical ventilation heat recovery system (MVHR) to maintain a constant supply of fresh air within the properties. MVHR units use the heat from outgoing stale air to warm incoming fresh air, further reducing the property’s heating demand and creating a fresh and comfortable indoor environment.