When considering building your dream home, energy efficiency is a crucial factor that affects not only your monthly bills but also your overall living comfort. One key aspect of energy efficiency is airtightness. But what does it mean, and why should you care?

Understanding Airtightness

Airtightness refers to how well a building prevents air from leaking through its envelope—the walls, roof, windows, and doors. The tighter the building, the less air escapes, keeping the indoor temperature stable and reducing the need for heating or cooling.

The Evolution of Airtightness Standards

Ten years ago, the standards for airtightness were much less stringent than they are today. In the early 2010s, the maximum allowable air permeability for new buildings in England and Wales was set at 10 m³/h.m² at a pressure of 50 Pascals. This means air could be replaced up to 10 times per hour, resulting in significant energy loss and higher utility bills.

Today, the standards have become much stricter. Modern homes are now built to much lower air permeability levels, often below 5 m³/h.m², with many high-performance homes targeting even lower values. Some builders, including us, aim for sub-4 m³/h.m² and strive to push the boundaries of energy efficiency even further with each project.

Current Regulations and Testing

Current regulations, as outlined in Part L (Conservation of Fuel and Power) of the Building Regulations, require new buildings to meet specific airtightness standards. For instance, new dwellings must not exceed an air permeability of 10 m³/h.m², though high-end builds often aim for much better performance.

Airtightness is measured using a blower door test. This test involves placing a large fan in an exterior door to pressurise or depressurise the building and measuring how much air escapes. Qualified testers conduct these tests to ensure accuracy and compliance with the regulations.

The Importance of Airtightness

So why is airtightness so crucial? It's simple: the more airtight your home, the less energy you need to keep it warm in the winter and cool in the summer. This not only lowers your energy bills but also reduces your carbon footprint, contributing to a more sustainable future.

Moreover, a well-sealed home enhances comfort by eliminating drafts and maintaining a consistent indoor temperature. It also helps prevent moisture ingress, which can lead to mold and other issues that affect your home's longevity and your family's health.

Achieving Superior Airtightness

Achieving superior airtightness requires meticulous attention to detail during the design and construction phases, which is why we like to be included all the way. This includes:

• Design: Incorporating airtight design features such as continuous air barriers, high-quality windows and doors, and proper sealing of joints and penetrations.

• Construction: Ensuring builders and contractors follow best practices, such as using appropriate sealants, tapes, and membranes and conducting regular inspections throughout the build process.

Beyond Regulations

While the UK government updates building regulations to improve energy efficiency, some regions have adopted even more rigorous standards. For example, Scotland has adopted Passivhaus Standards for new housing, emphasising extremely low energy consumption and high comfort levels. The regulations are constantly changing, and we are striving to stay ahead of them.

Conclusion

Airtightness plays a significant role in the energy efficiency and comfort of your home. By understanding and prioritising airtightness, you can enjoy lower energy bills and a more comfortable living environment and contribute to a more sustainable future. When building your dream home, consider partnering with experts who understand the intricacies of airtight construction and are committed to achieving the highest standards. Your investment in airtightness will pay off in the short and long term.