Dwelling type

According to Approved Document L1A of the Building Regulations, the term 'dwelling type' refers to:

...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.

NB The 2015 edition of Approved document M, Volume 1: Dwellings, introduced three different types of dwelling for the purposes of setting out requirements for access to and use of buildings:

• 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.

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[edit] 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.