Wales unveils net zero pattern book

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Unveiled at the University of Wales Trinity Saint David in Swansea on 15 January, the pattern book has been developed with support from the Welsh Government and twenty-three social housing providers who came together under the name Tai ar y Cyd. The book sets out fifteen house typologies across two building performance standards, AECB CarbonLite and passive house classic.

The AECB CarbonLite new building standard is the baseline standard and draws on the passive house methodology, with a target space heating demand of 40 kWh/m2/year. The enhanced standard targets the passive house classic standard, with a space heating target of 15 kWh/m2/year (or peak heating load of 10 W/m2/year).

Steve Cranston, project lead on the Tai ar y Cyd project said the two performance targets were chosen to be “ambitious yet achievable”.

“They meet the needs of member landlords who wanted an ambitious ‘entry level’ place to start as well as an advanced position for landlords ready to push their ambition further. This approach has been found to suit the Welsh timber frame manufacturers and supply chain. Welsh government colleagues in the standards/technical scrutiny team were closely involved in this decision,” he said.

The pattern book is intended to make it easier for Welsh social housing providers to meet Welsh Development Quality Requirements (WDQR) 2021, criteria for a ‘fabric first’ alternative option to EPC A with a space heating target of 40 kWh/m2/year. Both the baseline and enhanced standards will be accepted for Social Housing Grant technical scrutiny and grant application. The project is also aligned to the RIBA 2025 embodied carbon limit of <800 kgCo2e/m2 as a minimum and aiming for RIBA 2030 minimum carbon limit of <625 kCo2e/m2.

Speaking ahead of the launch at a visit to Celtic Offsite in Caerphilly, a social enterprise within the United Welsh Group that manufactures timber homes from their factory, Welsh cabinet secretary for housing and local government, Jayne Bryant, said the Tai ar y Cyd patten book represented a “significant step forward” in the government’s commitment to building sustainable and affordable homes in Wales.

“We know that there is a real need for good quality and energy efficient homes across our communities, and this innovative pattern book give developers the tools they need to build homes more quickly and deliver against our target of building 20,000 affordable low carbon homes by the end of this Senedd term,” she said. The pattern book also received a welcome from the Association for Environment Conscious Building (AECB), with a spokesperson saying it was an "exemplar" and that the industry body was “delighted to have our new build standard adopted in Wales and to be included in the pattern book. We wholly endorse the project and are poised to support further development in any way we can.”