The consultation paper for the 2010 revisions for Building Regulations is now out for scrutiny and comment.
A summary of the key factors affecting Air Testing are detailed below.
- L1A air permeability target reduced to 7m3/h/m2
- Increased sample of dwellings to be tested in L1A
- Revised definition of a dwelling type for L1A
- New measures for a dwelling type not tested in L1A
- Non Residential air permeability target reduced to 5m3/h/2
Perhaps one of the most significant factors is the tightening of the definition of a dwelling type
From:
- A dwelling type is defined as a group of dwellings on a site having the same generic form (detached, semi-detached including end terrace, mid terrace mid-floor flat, ground-floor flat, top-floor flat) and where the same construction methods are used for each of the main elements (walls, floors, roofs etc). Small variations in the floor area do not constitute a different dwelling type.
To:
- Dwelling type is a means of allocating each dwelling on a development to a particular group to provide the basis for assessing the pressure testing regime. To be classed as of the same type dwellings have to:
- i)be of the same generic form (i.e. detached, semi-detached, end terrace, mid terrace, ground floor flat (inc. ground floor maisonette), mid floor flat, top floor flat (inc. top floor maisonette);
- ii)be of the same number of storeys;
- iii)be of the same design air permeability;
- iv)have similar adjacency to unheated spaces such as stairwells, integral
garages etc;
- iii)have the same principal construction details (as identified by the ACD or bespoke detail reference codes);
- iv)have a similar (i.e. ±1) number of significant penetrations, i.e. for windows, doors, flues/chimneys, supply/exhaust terminals, waste water pipes);
- vii)have envelope areas that do not differ by more than 10% (see air permeability for a definition of envelope area).
The relevant documents can be viewed at http://www.communities.gov.uk/publications/planningandbuilding/partlf2010consultation
Click here for the pdf consultation vol 1
Click here for the pdf consultation vol 1
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