Changes to Building Regulations Document L and how it impacts glazed doors specification

From the glazing industry’s perspective, the changes to Building Regulations in June 2022 have been the most significant in a generation, with the expectation that thermal efficiency standards will tighten even further in years to come to adhere to the much anticipated Future Homes Standard.

Two part standard for glazed doors

From a glazed door perspective, there has been a significant tightening of the U-values required for doors, for Part L1B this sees the figures required improve from 1.8 W/m²K to 1.4 W/m²K on extension and renovation projects. For new-build homes, Part L1A offers slightly more flexibility as the doors are included as part of an overall building calculation, so whilst a nominal figure of 1.2 W/m²K is included within Approved Document L, doors can achieve 1.4 W/m²K if additional thermal efficiency measures are taken elsewhere on the project. Learn more

No more hidden frames

One key element to glazed door design that has changed in recent years is how the overall U-value of a system is calculated. Previously only the visible elements of the frame were included within the calculation so if you recessed the outer frames into the walls you were able to claim an improved thermal performance. That is now no longer acceptable; the entire frame of the system has to be included which has caused some products on the market significant issues because, typically, the outer frame of the system has been the least thermally efficient element of the whole door system. Learn more

How do IDSystems doors perform?

From an IDSystems perspective the enhancements to Building Regulations Document L hasn’t impacted the design of our doors significantly, we have always calculated the true U-value of the system so the figures you see for our aluminium sliding doorsbifold doors and slide & turn doors already include the outer frames in those performance standards.

Our aluminium bifold doors were already the most thermally efficient aluminium folding door solution on the market, whilst our triple-glazed vistaline system and theEDGE2.0 ultra-slim sliding doors also comply with the performance requirements. Learn more