Title: Re: Failed rendering - recommended approach
Post by londonman on Mar 8th, 2010, 10:00pm
Yup...I was as surprised as you are but it is there in black and white.
Building Control Guidance Note
Subject
CONSERVATION OF FUEL AND POWER 2006.
Guide 5 – APPROVED DOCUMENT L1B Conservation of fuel and power – Work in existing dwellings.
24
Issued 07/04/06
Rev
Page
1 of 11
From 6th April 2006 there are significant changes to the Building Regulations that cover the Conservation of Fuel and Power in buildings. Energy performance relating to works and extensions in existing buildings is based on a revised elemental approach in which insulation and efficiency thresholds are set for individual parts of the building envelope and services.
There are requirements for standards to be achieved for ‘Thermal Elements’ (walls, floors and roofs), ‘Controlled Fittings’ (windows, doors and similar fittings) and ‘Controlled Services’ (heating, hot water, ventilation systems and lighting). Regulations apply whether as part of an extension, dividing a house into flats, replacing windows, extending a heating system or applying render to a gable wall, or changing a buildings energy status.
Extract of L1. GUIDANCE ON THERMAL ELEMENTS.
Thermal Elements - (Refer to Guide 24 – (2) for further guidance) refers to a wall, floor or roof that separates the heated or cooled space from the outside. Works relating to thermal elements can arise in building an extension, a material change of use, a material alteration, changing a buildings energy status or when carrying out other renovation works. Refer to guide 24 (2).
The requirements for ‘Thermal Elements’ represent a significant change in regulation since it requires efficiency improvements whenever a roof, wall or floor is replaced or renovated. Thus the replacement of render or tile hanging to a wall will require insulation works to be undertaken at the same time. The AD gives guidance on the U values that should be achieved depending on whether an element is newly constructed, rebuilt, retained, replaced or renovated. NOTE: consider carefully the potential for condensation problems and the controls necessary to prevent it when upgrading existing construction).
Renovation of ‘Thermal Elements’: is defined as the provision or replacement of a construction layer, such as external render, tile hanging or internal plaster. It would not include decorations or re-pointing brickwork. Where 25% or more of an elements surface area is to be renovated the whole element should be thermally improved (see AD L1B Table 4 (b) extract below).
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