Air Testing has numerous names which are used interchangeably within construction. The most common names in circulation include: air testing, air loss testing, air leakage testing, air pressure test, blower door, air permeability testing and fan testing. In principle all these names mean the same thing: Air Testing and correspond to particular procedures of testing and standards detailed in multiple areas of legislation. Air pressure testing calculates the air tightness of a building, known as its ‘air permeability’ or ‘leakage’ rate. For most (even professionals), this can be very confusing especially when asked by a Building Control Officer to provide certification that the construction meets the required standards.

Part L1A and L2A (England & Wales), Section 6 (Scotland) or Part F1 (Northern Ireland) of The Building Regulations require Air Pressure Testing. Air Pressure Testing has been mandatory for all new build residential and commercial properties in England, Wales and Northern Ireland since 2006, and in Scotland since 2010.

Air Testing

Air Permeability Testing is the process of measuring the amount of conditioned (heated or cooled) air leaking from a building through uncontrolled ventilation. A fan is installed into the external envelope of the dwelling (supplying air into or extracting air out of the property) creating a pressure difference. The tester will temporarily seal openings to the property before switching the fan on. The Air Tester uses calibrated equipment and calculates an air flow into, or out of the property. The air pressure is gradually increased and decreased, recording the pressure differential at each step

Air Permeability Testing ensures the building meets or exceeds the air permeability rating specified in a design stage SAP or SBEM Calculation. Maintaining a high level of air tightness within a building helps with energy efficiency. For example: air entering and escaping a building can lead to lost heat and cold draughts. Any dwellings that are not tested are subject to an increased result of +2 m3/h/m2 based on the average result for those that have been tested for plots of the same layout.

There are many benefits to an airtight property, such as:

• Lower Heating Costs
• Lower Carbon Emissions
• Smaller requirement for Heating and Ventilation systems
• Better comfort for occupants

Air leakage can occur through gaps, holes or cracks in the fabric of the building. Excessive air leakage can affect the building’s energy efficiency, making the building less energy efficient and more expensive to run. Compliance 4 Buildings when instructed provide a guide to preparing a property for Air Permeability Testing.

Building Regulations Approved Documents L1A and L2A

In Approved Document Part L1A of the Building Regulations, air tightness testing is referred to as Pressure Testing. The test methodology for measuring the air tightness of a building is set out in ATTMA Technical Standard 1. Technical Standard 1 is based on BS EN Standard 13829:2001, Thermal Performance of Buildings – Determination of Air Permeability of Buildings – Fan Pressurisation Method and ISO 9972:2015.

Under Approved Document L1A: Conservation of fuel and power in new dwellings, if you have built a new build dwelling or development of 2 or more dwellings / flats, then you will need to carry out air permeability tests for the development. The number of tests that will be required will depend on the size and configuration of the dwellings involved. It is a requirement of Part L1A that any dwelling tested must achieve an air pressure test result (or air permeability) of less than or equal to 10m3/h/m2 at a pressure differential of 50 pascals.

Under Approved Document L2A: Conservation of fuel and power in new buildings other than dwellings, if you have built a new build premise other than a dwelling, then you will need to carry out air permeability tests for the development. The numbers of tests that will be required will depend on the size and configuration of the development involved.

Equipment

Unsurprisingly the equipment utilised for Air Permeability Testing is highly specialised and requires regular and consistent testing to maintain accuracy. All Compliance 4 Buildings Ltd equipment is calibrated by a UKAS approved laboratory to maintain accuracy during a field test.

Compliance 4 Buildings is registered with ATTMA which regularly audits results to maintain standards and accuracy. If you are unsure if your development requires an Air Permeability Test, Compliance 4 Buildings are able to help. We also provide free, no obligation quotes at very competitive rates for all sizes of project.