Building Regulations 2000 introduced new regulations specifically to the conservation of fuel and power in buildings that came into effect in April 2002.  Approved document L1 sets out the requirements for new and existing homes.  To download your copy click here.

The Building Regulations apply to the replacement and installation of windows, roof lights, roof windows, doors (with more than 50% of the internal facing is glazed), space heating or hot-water boilers, or a hot-water vessel.

For windows, doors and roof lights on any house type, energy-efficient improvements are required where the elements are to be fully replaced.  However, the requirement does not apply to repair work on parts of doors, windows or roof lights, such as replacing broken glass or sealed double-glazed units, or replacing rotten framing members.  Building Regulations provide a range of opportunities for energy improvements. 

For more information on Building Regulations visit the Government website

To find out what you can do for energy efficient refurbishment  visit the Energy section.

Material alterations

When carrying out material alterations to the building in the following ways, energy improvements need to be made.

Roof insulation needs to be replaced to a standard matching new homes when substantially replacing any of the major elements of a roof structure in a material alteration, or when substantially replacing any of the major elements of a roof structure.  This should include improvements to airtightness.

Floor insulation needs to be installed to the standard for new homes where the structure of a ground floor or exposed floor is to be substantially replaced or re-boarded.  This should include improvements to airtightness.

A reasonable thickness of wall insulation, along with improvements to air tightness, should be installed when substantially replacing complete exposed walls or external renderings or cladding, or internal surface finishes. 

When upgrading insulation in accessible lofts where the existing insulation provides a U value less than 0.35W/m2K, you should install additional insulation to achieve a U value of 0.25W/m2K.

If buildings are subject to a material change of use, energy improvements are required in accordance with new-build standards.  Lighting needs to be provided in accordance with new-build standards.

Heating and Hot Water

Heating boilers

Changes to the building Regulations in 2005 could see the mandatory minimum rating for replacement boilers being set at B or even A. Visit http://www.boilers.org.uk/ for details. Currently if heating boilers are to be replaced in homes with floor areas greater than 50m², the boiler needs to be provided as if for a new home. 

Ordinary oil or gas boilers should be replaced with a boiler with an effective SEDBUK rating of at least 78 for gas and 85 for oil.  They need to include appropriate zone controls, timing controls and boiler-control interlocks.

Back boilers should have a separate rating of at least 3 percentage points lower than that shown above.

Solid-fuel boilers ? efficiencies must equal the recommendation for their type as set out in the HETAS certification scheme.

Hot-water vessels

When replacing hot-water vessels, equipment must meet the standard set out for a new building.   In normal cases this will have 35mm factory-applied insulation.  Good-practice standards suggest 80mm factory-applied insulation that does not contain HCFCs (this will become standard practice in 2004).

Boiler and hot-water storage controls ? these must achieve a reasonable seasonal efficiency and the work may need to include replacement of the time switch and programmer, room thermostat and hot-water vessel thermostat and provision of a boiler interlock and fully pumped circulation.

Alternatively, if work is carried out to the above elements in accordance with guidance in good-practice guide 155 (2001), this will be acceptable as long as the overall carbon index is achieved.  GPG 155 was updated in 2003 to exceed Building Regulations.  Green Street refers to the updated standards. 

Advice and information

In addition, information must now be provided for the operation and maintenance of heating and hot-water systems.  This could take the form of easy-to-understand guidance on the specific boiler and heating system installed.  It should also identify the level of routine maintenance needed for efficient operation.  Heating and hot-water systems should also be inspected after installation to ensure effective operation.  Responsibility for this lies with the contractor installing the systems.

A range of agencies, such as National Energy Action, can provide training and assistance to housing associations and their tenants on the correct use of heating controls.   (For more information, please see lifestyle section).