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England and Wales

The newly revised building regulations came into effect from 1st October and introduced a tougher set of energy performance standards for windows and doors installed into existing domestic dwellings and new extensions. A downloadable copy of these regulations and those affecting new build domestic dwellings can be found in our downloads section.

The major changes for replacement windows and doors in domestic properties and new extensions are required to meet the requirements of Approved Document L1B as detailed below.


Windows, Roof Window or Roof Light

BFRC Energy Rated C or better
U value 1.6 W/m2k



U value 1.8 W/m2k

PVCu and timber windows and doors fitted with low e argon filled double glazed sealed units incorporating a warm-edge spacer bar will achieve a combined 1.6 U-value and will be deemed to be compliant by building control following detailed simulations carried out by the BFRC.


Product Compliance

All our glazed products meet and exceed the requirements of the revised building regulations document L as shown below.

Timberlook Swish A rated PVCU windows 1.3 U value

Timberlook PVCu bifold doors and entrance doors

FD2U timber bifold doors achieved a 1.4 U value under BFRC simulated testing.

Visofold aluminium bifolding doors and Alitherm windows and doors are compliant with document L and have been subject to thermal simulation to BS EN ISO 10077-2 and BS EN 1435-1. Calculations are in accordance with BR 443.



Scottish building regulations were also revised on 1st October 2010 and you can download a copy from:

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