Communities and Local Government

• Planning, building and the environment
• Condensing Boiler Installation Assessment procedure

Planning, building and the environment

Condensing Boiler Installation Assessment procedure

Building Regulations Part L1 Condensing Boiler Installation Assessment Procedure

Use of this installation assessment procedure and form

From 01 April 2005, Part L1 of the Building Regulations requires gas and oil boilers installed in new and existing dwellings to be condensing types, with a SEDBUK efficiency in band A or B, unless there are exceptional circumstances that make this impractical or too costly.

For new or replacement boilers in existing dwellings, carry out the assessment and complete the form to see if your case is a permitted exception, and hence whether a non-condensing boiler may be installed instead of a condensing boiler. A correctly completed form may be used as evidence that it is permissible to install a non-condensing boiler. A form is not required when a condensing boiler is fitted.

Completed forms must be made available to:

• the householder, AND
• EITHER the building control body, if you have elected to notify the work to them,

OR retained by the Approved Competent Person and you certify work done yourself.

Refer to the Building Regulations Part L as amended ddmm 2005 for the legal requirements, and to the current edition of Approved Document L1 for guidance on compliance. Refer to the same documents for advice on how to deal with historic buildings.

The assessment procedure

The assessment is an examination of the building to find the position at which a condensing boiler can be installed at lowest cost, ignoring obstacles such as furniture or fitments and disregarding whether or not the position is acceptable to the owner. The lowest cost option is recorded on the form.

• The assessment must be carried out following the detailed guidance given in the Boiler Installation Assessment Procedure for Dwellings - GUIDE ("the Guide").
• The form must be valid for the date of assessment (see validity period at top) and signed by a registered competent person.
• The assessment must consider ALL feasible condensing boiler installation options (in all locations that meet regulations) for whichever fuel has been chosen by the customer (natural gas, LPG, or oil).
• The form must be completed for the installation option that gives the LOWEST points score.
• When the assessment score exceeds 1000 points, this is evidence of exceptional circumstances under which it is permissible to install a non-condensing boiler instead of a condensing boiler. The validity of the assessment is restricted to the chosen fuel for the new boiler.

After the assessment:

• if the completed form shows that an exception is allowed, a non-condensing boiler for the chosen fuel (shown in section 4 of the form) can be fitted to any design that meets customer preference. Nevertheless a condensing boiler is preferable, and the customer should be invited to consider that alternative.
• if the completed form shows that an exception is not allowed, a condensing boiler MUST be fitted but can be to any design that meets customer preference.
• whether a condensing or non-condensing boiler is fitted, it need not be in the position shown on the assessment form.