Part L: How it affects windows and door installers

In June Part L of the Building Regulations changed which has thrown up a lot of conversations of how best to achieve compliance. In this blog, we focus on the importance of setting clear specifications early in the process with aluminium fenestration manufactures like Altegra.

What is Part L?

Part L 2021, or Part L Conservation of Fuel and Power of the Building Regulations relates to construction projects for new buildings as well as improvements or changes to existing dwellings and other buildings. It defines the standards relating to energy efficiency, thermal performance and carbon emissions.

Consisting of these 4 documents

Approved Document L1A
Conservation of fuel and power in new dwellings

Approved Document L1B
Conservation of fuel and power in existing dwellings

Approved Document L2A
Conservation of fuel and power in new buildings other than dwellings

Approved Document L2B
Conservation of fuel and power in existing buildings other than dwellings

What are the major changes?

The changes impact the design of future products are designed, manufactured and installed with the aim of creating even more energy-efficient windows and helping to reduce energy consumption in new homes by 31% fewer emissions.

Glazing must now do more as part of an overall structure to bring the desired future requirement of virtually zero energy buildings. The below table shows the changes for new and existing dwellings.

You can view the entire government document here

What does this mean for window and door installers?

Many new installations will require background ventilation, such as Trickle Vents or trickle ventilators. These are a component within a window or a door, situated at the upper part of the frame. Their purpose is to provide permanent ventilation into the room, even with a closed window. These vents always allow a small amount of ventilation through the window. They come either as permanent or a controllable version, opening and closing.

The introduction of lower U-value targets and desire to become New Zero there are many low carbon solutions available. By leaning on your manufacturer who can share their specialist knowledge and provide an innovative solution.

A challenge of the new Part L for many installers is how to address the ‘performance gap’ and the need to ensure that buildings meet the same level of energy efficiency as they have been designed to achieve during the planning stage.

Several factors can affect this from product availability to the way it was installed. As mentioned by working closely with your manufacture you could switch specification from a standard aluminium window system that simply meets current U-value needs, to one that can offer improved thermal-efficiency that exceeds them which in turn will ‘future proof’ the installation. As a result, this can reduce risk and time through expensive redesigns.

Aluminium is great for the recycling message. PVCu has a serious credibility challenge with the worldwide perception of plastic right now. Hybrid comfortably provides the best of aluminium with the sustainability credentials of wood with superb U-Values. Lower U-value aluminium windows offer excellent value for money and can eliminate the need for more expensive elements such as under floor heating and photovoltaic roof panels.

Reducing U-values will prevent cold air leaving the room, which means radiators can be moved to under windows freeing up wall space.

With a further possible change in 2025 getting suppliers such as Altegra during the planning stage can pay dividends in finding the best solution for your project.