Pressure Testing / Air Permeability Testing

The SPHC offers pressure testing for domestic properties in Scotland, England and Wales. Please contact us for a quotation: 0845 3883 716

How does the test work?

Before the test is carried out temporary openings have to be sealed. In order to ensure minimal disturbance on site, we work closely with the construction team to assess suitable times for testing.

Our technician will seal the entrance door and apply the test equipment to carry out the test, whereby the house is set under pressure of 1.6 bar / 50 Pa.

For the testing of Passive Houses the test needs to be done with pressurising and depressurising of the building in order to show if there are any loosely connected air tightness membranes.

The air leakage is measured in two values:

- q50: m³/h/m², measuring the amount of air leaking out of the building at 50Pa within one hour in relation to the external surface of the building.  This value is needed for SAP.

- n50: 1/h, measuring the air exchange rate at 50Pa. This value is needed for the Passive House calculations.

What does it show?

The pressure test shows the general air tightness integrity of the building; i.e. the amount of drafts and heat losses that can be expected in the operation of the building.

Often definite leakage paths can be detected, especially if the test is done in conjunction with a smoke test or thermal imaging. This shows if the windows and doors have been fitted correctly, if there are any leaks through the joints of the building fabric or leakage paths through electrical sockets, pipework, etc.

Remedial measures are more easily done when the test is performed at the stage of wind and water tightness, before the plaster boards have been fitted.

How long does it take?

A typical test on a 1500sq ft dwelling normally takes around 2 - 3 hours. On a larger development site, or an apartment complex, we are able to liaise with the site agents to coordinate our testing with the various trades during a typical day to ensure minimum disturbance. Others may be present on the dwelling during the test.

Test results can be sent to you normally within 3-5 working days.

What do you need to prepare?

For a speedy test result, plans of the building area envelope and all on site measures should be sent to us as soon as possible.