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Applies to the following conditions
• Consequential Improvements
• A Material alteration
• An Extension
• The provision of a controlled service
• The provision or renovation of a thermal element

Special consideration for historical buildings (i.e. listed buildings; buildings of local architectural and historical interest; buildings in conservation areas as identified by local planning authority):
• Improve energy efficiency where possible
• Follow English Heritage guidance on Building Regulations
• Agree strategy with Building Control Officer

Consequential Improvements
Requires whole building to comply with Part L if the useful area is greater than 1000m2 where the proposed work includes:
1. Extension; or
2. Initial installation of building systems: or
3. An increase to the installed capacity of any fixed building services

Requires whole building to comply with Part L if:
• Extension area is greater than 100m2 and is greater than 25% of the total floor area of theexisting building, limited by the 10% rule.
• Where there is an increase in the installed heating or cooling plant any thermal element (including windows) with a
• U value below the elemental standards ( defined in the Approved Document) must be upgraded in accordance set out in the document.

Upgrading thermal elements due to:
• Material change of use (e.g. refurbishment to create residential spaces)
• Material change (e.g. refurbishment of roof or walls)

Any thermal element that is being retained should be upgrade as follows:
• Cavity walls Improved U value 0.55 W/m2K
• Cladded walls Improved U value 0.26 W/m2K
• Pitched Roofs Improved U value 0.18 W/m2K
Limited by 15 year payback rule (i.e. the measure provides a 15 year economic payback)

For more information please email: or call 0161 438 72 51