Air Pressure testing on New Houses by CPS Leakage
Details of dwelling type definition criteria, air test regimes and common leakage paths are listed below
CPS Leakage carries out air leakage and air pressure testing on new houses in Suffolk, Essex, Norfolk and Cambridgeshire. Based in Ipswich, we cover the Cambridge, Norwich and Chelmsford areas for residential air testing.
Details of dwelling type definition criteria, air test regimes and common leakage paths are listed below.
Air Leakage Testing Residential dwellings. L1A. Residential Air Testing for houses, bungalows and flats.Part L1A 2010: Relevant to Air Testing new residential dwellings for Building Regulation compliance.
- Dwelling Type definition by L1A 2010:
- A dwelling type is defined as a group of dwellings on a site having the same generic form.
- A detached, semi-detached, end terrace or mid terrace house.
- A ground-floor (inc. ground floor maisonette), mid-floor or top-floor flat (inc. top floor maisonette).
- Where the same construction methods are used for each of the main elements (walls, floors, roofs etc).
- Be of the same number of storeys.
- Be of the same design air permeability from the SAP calculation.
- Have similar adjacency to unheated spaces such as stairwells, integral garages etc.
- 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%.
Air Test Regime from 2010 Regulations
- On each development air testing 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.
- A block of flats for air leakage testing, should be treated as a separate development from another block of flats on the same site.
- The dwellings to be air tested should be taken from the first completed batch of units of each dwelling type.
- Those dwellings selected for air tightness testing should be selected so that about half of the scheduled tests, for each dwelling type, are carried out during construction of the first 25 per cent of each dwelling type.
- All air tightness tests on dwellings in the sample should be reported including any test failure.
- In the event of an air permeability test fail that dwelling must undergo remedial works so that it passes and another of the same dwelling type air tested.
- Where a dwelling of a type has not been air tested, the assessed air permeability is the average air test result obtained from other dwellings of the same dwelling type on the development increased by a margin of +2.0m3/h/m2 at 50pa.
- In the event that the average of those air tested does not permit those not air leakage tested to pass, then more must be air permeability tested in an attempt to reduce the average.
- For developments of two or less dwellings then a figure of 15 m3/hr/m2 can be used for the SAP Calculation and no air test is required if the SAP calculation passes. Alternatively if the same contractor has built the same design in the previous 12 months and can prove a compliant result then no air testing is required.
- Should a residential air test fail, CPS's experienced staff will work with site to locate the air leakage paths and advise on sealing. Once the leakage paths are sealed by site we will carry out further air tests on the same day to try to obtain compliance. CPS Ltd has carried out air leakage and air pressure testing in thousands of new houses and residential buildings in Suffolk, Essex, Norfolk and Cambridgeshire.
A few common air leakage paths (other than unfinished items) are as follows:
- Under skirting and so up behind dot & dab.
- Through penetrations / holes in plasterboard hidden behind kitchen units.
- Around boiler flue penetrations to the external walls.
- Through soil stack boxing not sealed allowing leakage to the roof void.
- Around toilet pipe work penetrations to the external walls.
- Around radiator pipework penetrating the floor or the plasterboard.
- Through service penetrations into the plasterboard and floor underneath a bath.
Air testing a new build in Suffolk or Top Tips for Passing an Air Tightness Test