Approved Document L1B - Conservation of fuel and power in existing dwellings

This document covers the use of fuel and power within existing dwellings, which also includes extensions and renovations. U-value standards for walls, floors, roofs, windows, doors and rooflights are shown. The document also covers fittings and services, such as windows, doors, heating and hot water systems, and lighting.

Download current Approved Document L1BApproved Document L1B

PDF file: 6.84MB, 32 pages

2013 edition incorporating 2010, 2011, 2013, 2016 and 2018 amendments: Valid from 5 April 2018

Quick links

The requirements in this edition of Approved Document L1B are as follows:

L1 - Conservation of fuel and power
Reasonable provision shall be made for the conservation of fuel and power in buildings by:
(a) limiting heat gains and losses:
(i) through thermal elements and other parts of the building fabric; and
(ii) from pipes, ducts and vessels used for space heating, space cooling and hot water services;
(b) providing fixed building services which:
(i) are energy efficient;
(ii) have effective controls; and
(iii) are commissioned by testing and adjusting as necessary to ensure they use no more fuel and power than is reasonable in the circumstances; and
Regulation 40 providing to the owner sufficient information about the building, the fixed building services and their maintenance requirements so that the building can be operated in such a manner as to use no more fuel and power than is reasonable in the circumstances.

Limits on application
None

Archived copies of Approved Document L1B

Download current Approved Document L1BApproved Document L1B - 2013 edition incorporating 2010, 2011, 2013 and 2016 amendments

PDF file: 260KB, 31 pages

Valid from 6 April 2016 until 5 April 2018

The requirement in this edition was:
L1B - Conservation of fuel and power in existing buildings


Download current Approved Document L1AApproved Document L1B - 2010 edition incorporating 2010, 2011 and 2013 amendments

PDF file: 306KB, 33 pages

Valid from 6 April 2014 until 6 April 2016

The requirement in this edition was:
L1B - Conservation of fuel and power in existing buildings


Download Approved Document L1B 2010 edition incorporating further 2010 and 2011 amendmentsApproved Document L1B - 2010 edition incorporating further 2010 and 2011 amendments

PDF file: 318KB, 31 pages

Valid from 1 October 2010 until 6 April 2014

The requirement in this edition was:
L1B - Conservation of fuel and power in existing buildings


Download Approved Document L1B 2010 editionApproved Document L1B - 2010 edition

PDF file: 493KB, 34 pages

Valid from 1 October 2010

The requirement in this edition was:
L1B - Conservation of fuel and power in existing buildings


Download Approved Document L - List of revisions and correctionsApproved Document L - List of revisions and corrections

PDF file: 318KB, 25 pages

Valid from March 2010 until 1 October 2010


Download Approved Document L1B 2006 editionApproved Document L1B - 2006 edition

PDF file: 318KB, 39 pages

Valid from 6 April 2006 until 1 October 2010

The requirement in this edition was:
L1B - Conservation of fuel and power in existing buildings


Download Approved Document L1 - 2002 editionApproved Document L1 - 2002 edition

PDF file: 393KB, 59 pages

Valid from 1 April 2002 until 6 April 2006

The requirements in this edition were:
L1 - Conservation of fuel and power


Approved Document L 1995 editionApproved Document L - 1995 edition

No download currently available

Valid from 1 July 1995 until 1 April 2002

The requirement in this edition was:
L1 - Conservation of fuel and power


Approved Document L 1990 edition with 1992 amendmentsApproved Document L - 1990 edition with 1992 amendments

PDF file: 4.64MB, 25 pages

Valid from 1992 until 1 July 1995

The requirement in this edition was:
L1 - Conservation of fuel and power


Approved Document L 1990 editionApproved Document L - 1990 edition

No download currently available

Valid from 1 April 1990 until 30 June 1995

The requirement in this edition was:
L1 - Conservation of fuel and power


Approved Document L 1985 editionApproved Document L - 1985 edition

No download currently available

Valid from 11 November 1985 until 1 April 1990

The requirement in this edition was:
L2 & 3 - Resistance to the passage of heat
L4 - Heating system controls
L5 - Insulation of heating services


Quick links to other Approved Documents

The regulations cover all aspects of construction and are constantly reviewed. The guidance documents referred to as 'Approved Documents' contain practical ways and explanations of how to comply with the functional requirements of the Building Regulations.

These 'Approved Documents' are separated into 20 parts:

  • Part A - Structure
  • Part B (Volume 1) - Fire safety (Dwellings)
  • Part B (Volume 2) - Fire safety (Buildings other than dwellings)
  • Part C - Site preparation and resistance to contaminants and moisture
  • Part D - Toxic substances
  • Part E - Resistance to the passage of sound
  • Part F - Ventilation
  • Part G - Hygiene
  • Part H - Drainage and waste disposal
  • Part J - Combustion appliances and fuel storage systems
  • Part K - Protection from falling, collision and impact
  • Part L1A - Conservation of fuel and power in new dwellings
  • Part L1B - Conservation of fuel and power in existing dwellings
  • Part L2A - Conservation of fuel and power in new buildings other than dwellings
  • Part L2B - Conservation of fuel and power in existing buildings other than dwellings
  • Part M (Volume 1) - Access to and use of buildings (Dwellings)
  • Part M (Volume 2) - Access to and use of buildings (Buildings other than dwellings)
  • Part P - Electrical safety - Dwellings
  • Part Q - Security - Dwellings
  • Part R - Physical infrastructure for high-speed electronic communications networks
  • Regulation 7 - Materials and workmanship