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Last edited 29 Jan 2018
...the particular group allocated to each dwelling on a development to provide the basis for assessing the pressure testing regime. The allocation of each dwelling to a dwelling type should be the responsibility of the person carrying out the pressure testing. To be classed as of the same type, dwellings should:
- Be of the same generic form (i.e. detached, semi-detached, end terrace, mid-terrace, ground floor flat (including ground-floor maisonette), mid-floor flat, top-floor flat (including top-floor maisonette).
- Include the same number of storeys.
- Have the same design air permeability.
- Have similar adjacency to unheated spaces such as stairwells, integral garages etc.
- Have the same principal construction details.
- Have a similar (i.e. +1) number of significant penetrations, i.e. for windows, doors, flues/chimneys, Supply/exhaust terminals, waste water pipes.
- Have envelope areas that do not differ by more than 10 per cent.
- Category 1 – Visitable dwellings.
- Category 2 – Accessible and adaptable dwellings.
- Category 3 – Wheelchair user dwellings.
See: Types of dwelling in approved document m for more information.
 Find out more
 Related articles on Designing Buildings Wiki
- Air permeability.
- Air permeability testing.
- Air tightness in buildings.
- Approved documents.
- Building emission rate.
- Dwelling emission rate.
- Energy performance certificates.
- Standard assessment procedure.
- Target emission rate.
- The history of non-domestic air tightness testing.
- Types of dwelling in approved document m.
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