Fabric first alternative option for Welsh social housing

Welsh social housing funding criteria includes a ‘fabric first’ alternative to EPC A requirements, that draws on the Passivhaus methodology, and has implications for the rest of the UK.

In a ground-breaking move, the Welsh Development Quality Requirements (WDQR) 2021, supplemented by an FAQ addendum, has set out a ‘fabric first’ alternative option to EPC A that social housing providers can opt for.

The alternative option draws heavily on the Passivhaus methodology and the AECB newbuild standard, with a space heating target of 40 kWh/m²/year.

Key benefits:

• More accurate methodology: The EPC methodology has been widely criticised for failing to deliver genuine energy savings. Having an alternative that uses the more accurate PHPP (Passivhaus Planning Package) methodology is to be welcomed.
• Energy saving: The Alternative option target has been shown to offer a 50% reduction in heating demand and bills compared to an EPC A project without PV or batteries.
• Potentially cheaper: The fabric first alternative option requires either MVHR or continuous MEV for ventilation, but does not require solar PV or batteries, making it cost neutral or potentially cheaper than an EPC A project.
• Offers an alternative to solar PV: Solar PV panels are not suitable for every kind of housing typology (eg some flats and apartments) and so the ‘fabric first’ option offers an alternative route for social housing providers.
• Provides a pathway for the Passivhaus standard: By setting a space heating target of 40 kWh/m²/year the alternative option is helping the construction industry to move towards the Passivhaus space heating target of 15 kWh/m²/year.

The approach taken in Wales could offer a useful template for other parts of the UK. Setting the standard initially with space heating requirements matched to the AECB standard has been seen as an acceptable starting point for upskilling the supply chain within Wales. It also offers a clearly defined and deliverable path for the construction industry towards the Passivhaus standard.

A Net Zero Pattern Book has just been launched, with support from the Welsh Government and 23 social housing providers.

The Tai ar y Cyd pattern book sets out 15 house typologies across the two fabric first standards of AECB standard (baseline) and Passivhaus Classic (enhanced). The pattern book will help make it easier for Welsh social housing providers to adopt the ‘alternative proposals’ route to get project funding.

At the same time, the Passivhaus Trust is developing regional skills training options for architects and contractors, so that Wales has the supply chain to deliver these projects.

The Passivhaus Trust is also actively campaigning for the Passivhaus standard to be considered ‘deemed to satisfy’ building regulations in Wales and across the UK.