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Welsh social housing blazing a trail

NEW Welsh social housing pattern book targets AECB & Passivhaus standards

Tai ar y Cyd logo

The UK Passivhaus Trust welcomes the launch of the Welsh Government’s new Tai ar y Cyd Net Zero Pattern Book today (Wednesday 15 January 2025). The Pattern Book has been developed with support from the Welsh Government and 23 social housing providers.  Standardising sustainable, timber-based affordable homes for Wales, it sets out 15 house typologies across two building performance standards, AECB Carbonlite and Passivhaus Classic.

  • The baseline standard: Targets the AECB Carbonlite new building standard that draws on the Passivhaus methodology, with a target space heating demand of 40 kWh/m2/year.

  • The enhanced standard: Targets Passivhaus Classic, with a space heating target of 15 kWh/m2/year (or peak heating load of 10 W/m2/year).

The pattern book will help 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 kgCO2e/m2.

Tai ar y Cyd: Baseline and Enhanced Standards

 

We settled on two performance standards that would 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.

Steve Cranston, Project lead Tai ar y Cyd 

The Tai ar y Cyd project aims to address issues including:

  • Ensuring the delivery of better-quality new homes through common performance standards, with economies of scale and repetition providing opportunities for the supply chain to get better and better at delivering quality homes.
  • Helping with cost certainty as contractors will be pricing against standardised house designs and performance specifications, stripping  out risk and cost associated with pilot/bespoke projects.
  • Improve programme speed, with off-site manufactured processes helping build out schemes faster.
  • Increasing the use of natural low carbon materials such as timber and especially  more Welsh timber.
  • Reducing early design fees and so allowing more time/resources for design teams to be spent improving the quality of schemes and planning applications.

Tai ar y Cyd resources include:

  • Pattern Book: House layouts for 15 house types and 18 variants ranging from 1 bed flats to 4 bed houses. Plus 3 additional fully wheelchair accessible bungalows and flats. All homes are designed to meet WDQR and WHQS.
  • Design Guide: Comprehensive guidance on how to use the pattern book. The documents set out the design requirements and modelling assumptions which form the basis of the house designs.
  • Performance Specification: This sets out 2 performance standards and the common fabric design and key metrics. This will be used by the landlords to prepare specifications for use with main contractors and sub-contractors.
  • Pattern Book Details: Technical manual with detailed house type designs for use by timber frame manufacturers to build the homes in Welsh off site factories.

Tai ar y Cyd: Documents

 

The resources were shared at the Swansea launch event attended by over 300 in-person and online delegates. The resources are currently available to Welsh social housing providers. They will be used by the Tai ar y Cyd members' development teams and shared with partner architects, designers, consultants, timber frame manufacturers, main contractors, subcontractors and developers  Members are identifying sites across Wales to join a prototyping phase, which will be connected through a new Tai ar y Cyd Prototype Community of Practice, where project managers will be able to share, learn and build confidence in how to use these new resources.  The Tai ar y Cyd team aims to extend out to the Welsh social landlords who are not currently members, as well as nurturing a strong supply chain.

 

The Tai ar y Cyd project is an inspiring and pioneering collaboration between the Welsh Government and social housing providers to streamline delivery of low carbon homes in Wales. It is brilliant that the pattern book considers both operational and embodied carbon and we are delighted that Passivhaus standard homes have been modelled for the house types in the pattern book, as the ‘enhanced’ option for social housing providers. The Passivhaus Trust is keen to support the rollout of the Tai ar y Cyd project in any way we can, including supporting the deliverability of simple and cost-effective approaches.”

Jon Bootland, CEO, Passivhaus Trust

The Passivhaus Trust is developing regional skills training options for architects and contractors, to ensure Wales has the skilled supply chain it needs to deliver these high performance projects. It is also actively campaigning for the Passivhaus standard to be considered ‘deemed to satisfy’ building regulations in Wales and across the UK.

 

More information

Tai ar yd Cyd

Welsh Development Quality Requirements (WDQR) 2021

WDQR FAQ addendum 2023

Passivhaus social housing

Previous PHT story: ‘Fabric first’ alternative option for Welsh social housing - 15 January 2025

Previous PHT story: Exemplar local policies - 6 May 2022


15th January 2025


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