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08 Aug 2023

Masonry industry publishes Recognised Construction Details

The energy/thermal efficiency of new homes has never been under so much scrutiny, with energy, climate, and cost of living crises’ never out of the headlines and prominent changes to building regulations just around the corner. However, masonry construction, built correctly, can be exceptionally thermally efficient.

One common place heat can escape from a dwelling is at the junctions between building elements. Known as thermal bridges, the heat loss at these junctions is calculated independently of the U-values for the building elements themselves. A growing emphasis is being placed on optimisation around thermal bridging, not only because research shows that it can account for up to 30% of all heat loss from buildings, but because changes in incoming legislation are advocating a ‘fabric first’ approach to efficient homes. 

The uplift in Part L of the Building Regulations which came into force in June 2023, and the Future Homes Standard requirements which will operate from 2025 are targeting 75-80% reductions in carbon emissions from new homes. Putting fabric first means that the new thermal efficiency requirements and reductions in whole life carbon are to be delivered, as far as possible, by material and design choices rather than looking to active MEP (mechanical, electrical and plumbing engineering) measures.

As the construction sector gears up to build homes to the Future Homes Standard and the update to Part L there is a need to equip architects, designers, builders and energy assessors with the necessary tools to deliver efficient junction details. Part L defines two methods to assess Ψ values for thermal bridges; individually modelled values or using a database of independently assessed details.

The Masonry industry has come together to produce a free and easy to use resource housing such a database known as Recognised Construction Details ™ (RCD). The independently assessed thermal junction details contained within the database have been certified for use in demonstrating compliance with Part L of the Building Regulations.

Recognised Construction Details is a project commissioned by members of MPA Masonry and delivered by the Building Alliance and architects Studio Partington.

To access this resource visit:

In addition to providing an assessment of Ψ values Recognised Construction Details also provides a guide to constructing homes that meet the requirements of Approved Document B1: Fire Safety.

Concrete is an inherently non-combustible material with the highest fire safety rating of class A1, utilised correctly it can reduce risk and provide more reliable construction and greater confidence to customers.