Changes to Part L Building Regulations this year marked a key milestone towards delivery of the UK’s net zero journey. The next regulatory challenge for housebuilders is just two years away, with the introduction of the Future Homes Standard set to lay out a clear pathway for building the next generation of energy-efficient and climate-resilient homes. Here, Kealan Hunt, Commercial Director of Tarmac’s Blocks business, looks at what the changes mean for housebuilders and the steps they can take to build for the future.
If we are to achieve our net zero ambitions, it’s critical that we build healthy and sustainable homes.
Energy use in homes makes up 23% of the UK’s greenhouse gas emissions – more than double the amount from agriculture and nearly as much as all transport emissions. The UK can also lay claim to the oldest homes in Europe, with a typical home here in the UK cooling three times faster than Norway or Germany.
The introduction of the Future Homes Standard in 2025 is intended to go some way to meeting these challenges, ensuring that new homes are “future-proofed with low-carbon heating and world-leading levels of energy efficiency.” The roll out of the updated Part L Building Regulations in June 2023 marked the first transitional step towards this.
These new regulations will require new homes to deliver CO₂ savings of 31% compared to previous standards. Central to this is a ‘fabric first’ approach – changing mindsets around material specification and opting for high-performance, efficient products that minimise energy use. Homes built under the new standard must be ‘net zero ready’ and require no retrofitting.
Thermal bridges
Crucial to the new guidance is the assessment of thermal bridges. These occur when an area of a building has significantly higher heat transfer than the surrounding parts. Breaks in insulation, reduced insulation or more thermally conductive building materials can contribute to this.
The new regulations advise that “opportunities should be considered to use products that help to reduce thermal bridges. Options include…masonry construction: lightweight blockwork in the inner leaf of a cavity wall or both leaves of a party wall can help to reduce thermal transmittance, particularly at junctions, such as the ground floor to wall junction.”
Aerated blocks are an alternative to traditional dense and medium dense concrete blocks. Tarmac has recently refreshed its range of foundation blocks to support builders in complying with the new regulations. Our Durox and Toplite aerated blocks make compliance with Part L more achievable.
With compliance starting at the design stage, we’ve recently developed a U-value calculator to help establish the thermal performance of varying combinations of insulation and blocks. Tools such as these offer a more detailed assessment of the thermal performance of the wall proposed and are designed to support busy project teams.
Future ready
Embracing this fabric first approach and having an ambition to go beyond simply meeting Building Regulations will help housebuilders prepare for the challenge of further regulatory change from 2025. The building envelope will very clearly lie at the heart of a new sustainable way of thinking.
For more information on Tarmac’s range and its U-value calculator, visit www.tarmac.com/products/blocks