Part L

What are the Building Regulations?
The Building Regulations apply to most new buildings in England and Wales, and also to extensions, alterations and to change of use of existing buildings. They provide essential legislation and guidance for the building and construction industry.

What is Document L?
Document L sets the standards for energy efficiency (conservation of fuel and power) in buildings.

Why amend Document L?
As agreed in the Kyoto Agreement, the UK Government is committed to reduce the level of greenhouse gases. The Department of Environment, Transport and the Regions (DETR) issued proposals for energy efficiency standards in June 2000.

When will the amendment be implemented?
From the 1st April 2002 more energy efficient materials must be used in accordance with Document L, including replacement and new windows.

What will change?
The U-Value relates to the energy efficiency of combined frame and double glazed unit and is a measure of the rate of heat loss. U-Values are measured in Watts per square metre per degree of temperature difference (W/m².K). The lower the U-Value the lower the level of heat loss.

Previously the average U-Value of windows and doors should not have exceeded 3.3 W/m².K.
As from April 2002 the U-Value for windows and doors should not exceed 2.0 W/m².K.

What do you need to do?
After 1st April 2002, all installed windows whether replacement or new must meet the requirement of Document L and be subject to an inspection by a building control officer or installers must be registered to self assess installations.

To be able to self assess you must be registered with a WISA (Window Industry Self Assessment), government backed company.

This means that EVERY window installation company must be registered with a WISA company and all their window installation recorded.

Are there any exceptions?
Any window, rooflight or door having more than 50% glazing needs to comply to the new Document L. Therefore doors with less than 50% glazing do not have to comply. Listed properties and buildings in conservation areas may be exempt, as are display windows and shop entrance doors for the time being. If a conservatory is unheated and is not open to the house it will not have to comply with Document L.

What windows and double glazed units can be used?
Low Emissivity (Low-E) glazing. The U-Value of a window or door which uses low emissivity glazing is influenced by the emissivity. Usually double glazed units using Low-E glass (as long as the air space is 12mm or more) and glazed into timber or PVCu frames (as long as the frames pass regulations) should pass Document L requirements.

What are RedKite (Manufacturing) doing?
As from April 2002 RedKite are government approved and registered to carry out window and door installations and self assess work done to Document L requirements.
Our double glazed units incorporate high performance Low-E glass and our PVCu window and door profile tested to comply with Document L.

Where can I find out more about the Building Regulations Document L?
This page is designed to answer some of the key questions, however we recommend that you visit the DETR website for more information: www.safety.odpm.gov.uk/bregs/brpub/ad/ad-l1/index01.htm

:** IMPORTANT** YOU WILL NEED 'ACROBAT READER' ( ) TO VIEW THESE FILES. IF YOU HAVEN'T GOT IT, CLICK HERE TO INSTALL

To view the Building Regulations Document L Amendments (2002 Amendment)	partl2002main.pdf Click here
To view the full Part L Document 1995 (before the amendments)	partl1995full.pdf Click here
To view the Building Regulations Explanitory Booklet in English	buildingregs_explain_english.pdf Click here
To view the Building Regulations Explanitory Booklet in Welsh	buildingregs_explain_welsh.pdf Click here
To install Acrobat Reader (version 5.5) to view the files	AcrobatReader5_0_5setup.exe Click here