1st June 2017

Northern Ireland

Building Regulations for Northern Ireland, through Technical Booklet F (‘Conservation of Fuel and Power”), stipulate the air tightness testing of buildings. Currently, this requirement exists in both Technical Booklet F1 and F2:

Testing Requirements – Dwellings

Section 2.62 reads:

“On each development, an air pressure test should be carried out on three units of each dwelling type or 50 per cent of all instances of that dwelling type, whichever is the less; and at least one of each type should be tested. The dwellings to be tested should be taken from the first completed batch of units of each dwelling type to confirm the robustness of the designs and the construction procedures”

Section 2.63 reads:

“Each block of flats should be treated as a separate development irrespective of the number of blocks of flats on the site.”

Section 2.64 states:

“The dwellings selected for test should be chosen by the district council in consultation with the pressure tester. They should be selected so that about half of the tests on each dwelling type are carried out during the construction of the first 25% of the dwellings of that type. All tests on dwellings in the sample should be reported to the district council including any test failures.”

Section 2.65 reads:

“In addition to the remedial work on the dwelling that failed to achieve its design air permeability –
(a) one additional dwelling of the same type should be tested to increase the overall sample size; and
(b) other dwellings of the same dwelling type that have not been tested should be examined and, where appropriate, similar remedial measures should be applied.”

Dwelling Types

Technical Booklet F1 is very specific about what a ‘dwelling type’ is.

Section 1.2 states:

To be classed as of the same type, dwellings should: 

  1. 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 (including top-floor maisonette);
  2. include the same number of storeys;
  3. have the same design air permeability
  4. have similar adjacency to unheated spaces such as stairwells, integral garages etc.
  5. have the same principal construction details;
  6. have a similar (i.e. plus or minus 1) number of penetrations, i.e. for windows, doors, flues/chimneys, supply/exhaust terminals, waste water pipes;
  7. have envelope areas that do not differ by more than 10 per cent.”