Air Tightness Testing

What is it?

Testing the amount of air that leaks through a building is known as “Air Tightness Testing” and is measured by a term called “Air Permeability Rate”. This is the amount of excess (unwanted) ventilation due to draughts, cracks and poor construction methods. Anywhere draughts are found is considered to be losing heat and recent studies have shown energy savings of up to 30% through draft proofing buildings. In simple terms, this shows how “Leaky” your house is.

The process begins by sealing all vents in the building, which is considered to be controlled ventilation. A large fan unit is placed in the doorway of the building and a pressure is applied to the building. Areas where air is leaking through the building can then be identified using a Thermal Imaging camera. Data will be recorded from the test and the Air Permeability Rate can then be calculated.

If a good Air Permeability Rate is found at the time of first or second test the result can be used in the BER calculations which will improve your Building Energy Rating, should you need one.

For new buildings there are many new products and construction methods to help air tightness results which IBER can help you with at the design stage of your build covered in a BER Plan.

Required by Law!

Air Tightness Testing has now become a legal requirement for all new dwellings as it has been implemented into Building Regulations TGD L in Ireland. As from 1’st July 2008 all single dwellings applying for planning after this date will have to get an Air Tightness Test.

Multiple development requirements

On each development an air pressure test should be carried out on at least one unit of each dwelling type. One dwelling from the first four units of each dwelling type should be tested.
The basic number of tests for each dwelling type is presented in the following table.

The total number tested is related to the number of units of that type in the development and to the results achieved in any earlier tests carried out. Where a number of apartment blocks are constructed on the same site each block should be treated as a separate development irrespective of the number of blocks on the site.

Number of pressure tests per dwelling type:

Number of pressure tests required per dwelling type
Number of units	Number of tests required
1-4	One test
5-40	Two tests
41-100	5% of dwelling type
>100 (if target is reached)	2%
>100 (if target is not reached)	5%

A minimum air permeability rate has to be meet (10m 3 /m 2 h) and buildings that do not meet the minimum must have remedial work carried out and retested until it passes.

The results from the Air Tightness Test can then be used in the calculation of the BER certificate which will help your energy rating following a good air-tight result.