Shining a light on new regulations
A recent report from Checkatrade revealed that new windows were one of the top 10 home improvements last year. As consumers continue to invest in extensions and big-ticket purchases, specifiers need to be fully informed of the latest changes to Building Regulations. Here, David Loughran, Technical Team Leader at Keylite Roof Windows provides advice and recommendations.
There were several changes made to Building Regulations last year, including additions to Approved Document L, Conservation of fuel and power and Approved Document F, Ventilation. There was also the creation of approved Document O, Overheating.
The purpose of Part L is to ensure energy efficiency in buildings, with new and existing homes in England now being subject to higher building performance targets in an interim step towards the Future Homes Standard and Future Buildings Standard that will arrive in 2025.
When it comes to heat loss, one of the biggest issues for specifiers is thermal bridging. A thermal bridge, also called a cold bridge, is an area of a building construction which has a significantly higher heat transfer (loss) than the surrounding materials. One example of where this would occur is with junctions around windows, including roof windows.
If this area is not insulated it can lead to cold bridging on roof windows; this is where the gap between the roof and window creates a cold section all around the frame due to the temperature differentiation between the outside and inside, which contributes toward heat loss and can eventually lead to condensation and mould.
To make houses more comfortable and energy-efficient, the onus should be taken away from specifiers and products should be designed with optimum thermal efficiency in mind. Manufacturers should ‘design in’ features that eliminate thermal bridging, which reduces the risk of non-compliance and delivers a build that is closer to the expected energy performance.
Keylite has taken the lead in ensuring it removes the possibility of this occurring, ensuring its products are designed in such a way that specifiers don’t have to consider the ‘gap’.
Keylite’s patented integrated expanding thermal collar ensures the thermal integrity of the window and roof is as designed, thus removing the reliance on an additional thermal collar, and helping achieve Approved Document L recommendations concerning thermal performance. It also improves airtightness and Psi Values for SAP, supporting architects, specifiers and housebuilders to meet new regulations.
What’s more, Part F requirements for background ventilation are supported through Keylite’s cleverly designed top handle, allowing for controlled trickled ventilation when the window is fully closed and securely locked. National House-Building Council (NHBC) will not accept other window types that provide background ventilation by being latched in the partially opened position.