The measurement of air escaping from a building is called air tightness testing. It is also referred to as air permeability testing or air pressure testing. Since Approved Document L was reviewed in 2006, air tightness testing has become an essential part of building regulations for newly completed and rehabilitated buildings.
Because air leakage is the process whereby air escapes through any crack or hole in the building envelope and influences its energy performance, building regulations have been modified to ensure a building has adequate air tightness. Our Air Tightness Testing certificates are registered with Air Tightness Testing and Measurement Association (ATTMA), a professional association dedicated to promoting technical excellence in all air tightness testing and air leakage measurement applications. Located in Cottenham-Park, our company is a committed and accredited air permeability testing service provider; we provide air testing services. You can also contact us for assessments and consultancy services. In addition to air leakage testing, we provide Part F Mechanical extract fan flow rate testing.
We are registered members of the ATTMA. As a result, our air tightness certificates prove that the building requirements for your building have been met. We are professionals who take the time to explain the testing process, we are able to give informed advice on where problem areas may occur during testing, and how improvements can be made based on results of air pressure testing. AF Acoustics provides services that are cost effective and of high standard.
Air tightness testing is carried out to determine the volume of air escaping from holes in a building fabric. Other names for air tightness testing are air leakage testing and air pressure testing. Air leakage, also known as infiltration or draught, allows air to pass through unwanted leaks in a building; unlike ventilation where the air inside and outside of a building and its flow from one end to the other is controlled. Air leakage is uncontrolled ventilation. Air tightness testing is the approved method for gauging the entire air that has leaked through a building fabric. An excessive amount of uncontrolled air loss results in heat reduction, making the residents uncomfortable. As Government strives to reduce CO2 emissions from new buildings, building regulations now place greater emphasis on reducing air leakage from the building envelope. This reduces fuel consumption and CO2 emissions. Air tightness testing is important in establishing air leakage from a building’s fabric, the energy efficiency of a new building and in identifying poor build quality within new developments. Building plans will often consider air tightness at the beginning stages of development so as to measure up to stricter building standards. When the building fabric is properly constructed to reduce air loss, the building is economical, and energy efficient.
This occurs when openings in a building lead to excess air flow into and out of the building. When the circulation of air is properly monitored and bridled, ventilation has occurred. Another name for air leakage is infiltration. It may cause uncontrolled influx of air during frosty and windy weather. This reduces the temperature of the building, making the occupants uncomfortable. Air leakage plays a major part in the energy efficiency of buildings, and testing is necessary as a means of demonstrating that the air tightness targets used in building energy calculations have been achieved. Air tightness testing is compulsory for all new constructions and non dwellings with a floor area over 500m² in England and Wales. This came into effect in 2006.
Heat loss within a building can be caused by air leakage. During windy or cold weather, the infiltration of uncontrolled air through cracks in a building envelope occurs, leading to heat reduction. Movement of moist air into cavities in other parts of the building also occur. This process is called exfiltration. The air hits the cooler surface in the inner parts of the wall. Water vapour condenses and gathers in these gaps. Eventually, it is absorbed and starts a myriad of defects. Wooden sheathing or overlay becomes wet, making it weak.
As the years go by, these conditions can result in structural damage.
Other impacts include:
Successfully managing the movement of air into and outside the building will limit the damaging effects of moisture. Air leakage and vapour diffusion are minimised when barriers are installed. To get rid of pollutants, water vapour and moisture odour, the building must be well ventilated.
Air tightness is an important factor in a building’s energy efficiency and is part of government’s plan to battle environmental change by regulating the energy performance of buildings. Environmental change caused by carbon dioxide emissions and global warming is partly aided by the burning of fossil fuels to generate heat. When air leakage is controlled, heat loss and energy used by the heating system are reduced. Uncontrolled air leakage also results in health problems. Coupled with poor air circulation, it leads to the growth of mould and mildew. To “Construct tight, ventilate right” is the best practice. The result of uncontrollable air moving into the building fabric could be health problems and costly repairs.
It is best practice to conduct at least two air tightness testing procedures, one early in the build and another at the end. The test results are part of SBEM and SAP calculations, therefore they influence the total energy ratings of new buildings. It’s not a necessity to perform tests on each property, rather, different kinds of houses are selected and tested. Once every building in the residential development is not tested, the expected test result would have to be lowered by 2m3/h/m2. If 5m3/h/m2 was your target score, you must achieve 3m3/h/m2.
Where the dwelling has not been pressure tested, the assessed air permeability is the average test result obtained from other dwellings of the same dwelling type on the development, increased by +2.0 m3/h/m2 at 50 Pa. This type of testing does not reveal the exact air tightness of each residence and is therefore not advisable. Moreover, the penalty implemented on untested buildings makes the required air permeability rate difficult to attain.
At AF Acoustics, our air tightness testing expertise has helped many home and business owners in Cottenham-Park. Because of the following guarantees of working with us, we are highly endorsed by our clients.
Our vast experience in serving a variety of clients in Cottenham-Park guarantees we have the expertise to satisfy your needs regardless your unique circumstances, type or size of property. Our accredited air testing experts are polite and competent. They are trained to provide the service you need and fit around your project. If you need knowledgeable and trustworthy air leakage experts who can provide exemplary results, AF Acoustics is the team you need in Cottenham-Park.
AF Acoustics is a member of ATTMA, an association of specialists that concentrates on promoting the best air tightness measurements and air permeability testing techniques. It is the leading air permeability testing body in the UK and has recognised our competence and services.
Our comprehensive air permeability testing in Cottenham-Park is available. We offer responsive scheduling options. You can schedule for air tightness testing at your convenience. We guarantee no delays or complications regarding scheduling.
AF Acoustics has professional speedy services to satisfy clients who want their test results immediately. We have a next day turnaround policy for our test certificates and endeavour to deliver in all situations.
Save money by paying lower rates at AF Acoustics. As a business with low overheads, we’re able to give you one of the best air leakages testing services in Cottenham-Park at reduced costs.
Whatever the type and size of a domestic or commercial building in Cottenham-Park, AF Acoustics’ experts can test it for air permeability and issue an ATTMA certificate afterwards. An air leakage test is used to determine the level of uncontrolled air flow through gaps or cracks in the fabric of a building. The results are registered as The test results are described as m3/h/m2 – (m3 per hour) per square metre of building.
Approved Document L1A and L2A requires that buildings know their air permeability rates by taking the air leakage test. Each building tested must achieve a maximum air permeability rate of 10m3/h/m2. In order to comply with the carbon emission target, it may be necessary to achieve a lower air permeability rate. The required air permeability rate for each building can be found on the design-stage SAP assessment or SBEM for that building. Excess air leakage causes heat loss, greater carbon dioxide discharge and can make occupants uncomfortable due to the influx of cold air. It also causes wind washing and thermal bypassing, resulting in lower energy performance. The warm air within a building rises, leading to the influx of cold air through gap, cracks and other openings in the building envelope. The increasing difference in air pressure results in infiltration and exfiltration of air. Air permeability testing is a legal requirement for constructions in Cottenham-Park. This way, they can have high energy performance, meet building regulations requirements and get signed off by building control. Buildings where businesses are conducted will not cause discomfort to employees and clients because they have the legal air permeability rating. This increases the company’s productivity and lowers heating and cooling expenses.
Air tightness testing has been a compulsory part of the Building Regulations for new dwellings, renovations and commercial projects since the revision of Document L in 2006. Air tightness is referred to as air permeability or leakage rate. Any hole or crack in a building fabric is a spot where air leak can take place. Air leakage points are not often visible. The Building Regulations (Part L) demand that a selected group of different kinds of residential constructions and all non-domestic buildings greater than 500m2 perform air leakage tests. To adhere to Part L, make sure your building’s air permeability rate is not greater than 10m3/h/m2. Air leakage is vital to a building’s energy efficiency and is needed to meet Building Regulations Part L and carbon emission standards.
All your Part L and Part F testing requirements can be met by us. In addition to conducting your air pressure test and extract fan flow rate testing, we can put you in contact with professionals who provide SAP calculations, Energy Performance Certificates, and water calculations.
New buildings should ensure that all mechanical extract fans are tested for flow rate, as stipulated by Part F of the Building Regulations. The Building Control Body (BCB) has to see the results of the test as part of its sign-off procedure. Extractor fans can be tested and recorded, and test reports submitted using 3 methods. Use method 3 – the minimum benchmark method, which tests extractor fans with vane anemometers. This is our testing procedure.
Air Tightness Testing has different tiers, depending on how complex a building is and its size. Find them below: Level 1: Air pressure testing for single dwellings and other smaller non-dwellings up to 4000 m³ gross envelope volume, typically tested with a single blower door fan. The second level examines simple and complex buildings greater than 4000m3, with the exclusion of large zonal buildings and complex high rise (LCHR) buildings. Air tightness testing for phased, zonal handover and LCHR constructions is done.
An air leakage test is a test to determine the level of uncontrolled air flow through gaps or cracks in the fabric of a building. The result is expressed as a quantity in the form of m3 per hour, per square metre of building fabric. Air tightness testing is required for new builds. A lower air permeability rate might be needed due to carbon emission requirements. You can find the required air permeability rate of your building in its design-stage SAP assessment SBEM. Air leakage leads to heat loss, increased energy bills, greater CO2 emissions, and an uncomfortable atmosphere for inhabitants due to draughts.
Air tightness testing determines the extent of air leaking from a building’s envelope. The air leakage test result is written as m3/h/m2 – (m3 per hour) per square metre of building. Air tightness testing is required by Building Regulations. Each building tested must achieve a maximum air permeability rate of 10m3/h/m2. The SAP or SBEM assessment for all buildings reduces the air permeability rate target. The air permeability target can be found in a building’s design-stage SAP or SBEM assessment. Uncontrolled air leakage can cause several problems. They are: infiltration of cold air, discomfort, reduction in heat, and higher CO2 emission rate.
To ensure that the auto opening vent will perform optimally when fitted and commissioned, we test the smoke shaft to verify its air tightness. Smoke needs to be cleared out in the event of a fire. The automatic opening ventilation is a vital aspect of the fire strategy for high rise buildings. An air tight shaft creates sufficient pressure difference and ensures that the fans and vents perform properly to draw out smoke from a dwelling and save its occupants. We work towards air permeability targets set by the automatic-opening ventilation manufacturers that allow their equipment to operate effectively. The shaft undergoes air leakage testing when fans are placed inside it. The intended openings of the shaft (i.e. extract point and openings for ventilation grilles on each floor) are sealed off for the test so that the integrity of the shaft itself can be determined. This test is conducted before the automatic opening ventilation is fixed and commissioned.
The mandate to construct well insulated and air tight buildings, has made it crucial for satisfactory, enhanced and balanced ventilation systems to be installed. Extract fans are tested by us. This is done to meet the Building Regulations standard. Make sure the ventilation system is efficient, expels pollutants and odours, and reduces humidity, especially in kitchens and bathrooms. The air flow rates of all intermittent extractor fans, which are to be installed during the building process, are to be tested and the results submitted to the Building Control Body before work is completed.
Air tightness test determines the level of air permeability in a building. When air leakage is reduced in a building, the occupants will not experience discomfort and the energy performance will increase.
It is difficult to notice unwanted openings in a building envelope. They might be blocked by the internal finishes. The most acceptable approach to show that a building fabric is impermeable is to identify leakage paths within it.
Under the new regulations developers must test 20% of the dwellings on a site but this also depends on the amount of differing house types to ensure that a consistent sample is taken throughout the construction of the development. We recommend that all buildings be tested as those that aren’t are penalised.
The client needs to send our test engineers the drawings of the development (plans and elevations) and target air permeability requirements. The duration of air pressure testing is 30 to 60 minutes in most cases and the wind speed should not be more than 6m/s. Test engineers need the drawings and air permeability details from clients so that they can know the size of the building envelope and other information before arriving at the building. To get the site ready, make the place air tight by closing and securing all external doors, windows, ventilation and smoke vents. Remember to turn off range cookers or stoves a day before testing as well as mechanical ventilation systems, and fill all drainage traps.
We take the building envelope calculations before the test. The building envelope is the surface area of the structural barrier of a building. It separates the interior from the exterior part of the dwelling The calculations, which are extracted from the drawings, are fed into our estimations when testing your building for air leaks.
Air permeability, according to Approved Document L1A (2010), has to do with “air leakage rate per hour per square metre of envelope area at the test reference pressure differential of 50 pascals (50n/m2)”. The building’s envelope area has to do with the total area of all the floors, walls, and ceilings bordering the internal environment, including those below external ground level. These include shared walls, floors and ceilings in storey buildings. Internal dimensions are used to measure the envelope area.
Air change rates are often used as rules of thumb in ventilation design but they are seldom used as the actual basis of design or a calculation. Residential ventilation rates are measured based on the number of inhabitants and area of residence.
Measuring if the roof area and ground floor area of a building are the same is vital. A cold roof is a roof that has the thermal insulation put in the ceiling with wide space between the insulation and pitched roof rafters.
A warm roof is a roof system where the insulation is fixed along the rafters with an air barrier inside the insulation. The envelope area is the barrier between the conditioned space in the insulation and the unconditioned space outside.
Evaluate the weather (barometric pressure, wind speed and temperature) Place the fan on an aperture within the building envelope. Fix the instrument for testing. Calculate the air flow volume through the fan which equates to the air leakage. Gradually increase the speed of the fan to a maximum of 55-60Pa. At each fan speed, note the differences in air pressure in all the parts of the building.
We analyse the recorded air tightness test data and present the results to the client in a technical report. In the event of test failure, we advise the client on appropriate mitigation measures. Our expert knowledge will help in highlighting the areas of air leakage. Air Tightness Testing and Compliance
The positive effects of an air tight building with efficient ventilation (natural, mechanical or a combination) cannot be underestimated. Here they are: Lower heating bills due to less heat loss, with potentially smaller requirements for heating and cooling equipment capacities A functional ventilation system Your building will have less mould since moisture cannot escape into holes and cavities. Fewer draughts and enhanced comfort Be assured that you’ll get a test that meets all the regulations and standards no matter how big or small your building is. We provide air tightness testing, consultancy, design reviews and support services on all buildings, both dwellings and non-dwellings in Cottenham-Park. We also provide cost-effective, local service that complies with all relevant Building Standards.
The Building Regulations approved document Part L1A 2010 specifies that any new dwellings must be airtight. The regulation is focused on the conservation of fuel and power usage. Part L1A states that new dwellings should be tested for air tightness in accordance with existing regulations.
ATTMA has specified technical standards that must be adhered to while testing buildings in the UK, according to building regulations and other documents. BS EN 13829:2001 and ISO 9972:2015 are clarified by the technical standards. The technical standards provide rules that ensure testing organisations get the same results from the same kind of tests and are based on BS EN 13829 “Thermal Performance of Buildings. Determination of air permeability of buildings. Fan pressurisation method” and ISO 9972:2015, “Thermal performance of buildings – Determination of permeability of buildings – Fan pressurization method”.
If you’re constructing a new dwelling, you have to comply with Approved Document L1A’s stipulation to test it. For development with two or more buildings, three units of each dwelling type or 50% of the dwelling type should be tested. If the development has one or two dwellings only, an air tightness test might not be taken if the DET/TER calculations assume a value of 15m3/h/m2. To find if your building falls into this category, contact your SAP assessor. A testing procedure required by Building Regulations is expressed in ATTMA TSL1 for dwellings and ATTMA TSL2 for non-dwellings. Air leakage testing is required on all residential developments (this may be a sample of units) and certain Non-Dwellings. Buildings with a floor area of less than 500 m2 might not have to take the test. Where air tightness testing is not done, an assumed air permeability rate of 15 m3/h/m2 is used.
In January 2015, the ATTMA Scheme for Competent Air Tightness Testing Firms and Their Testers (The ATTMA Scheme) was launched. It is an industry competence scheme authorised by the government and specified in Technical Standard L1 & L2. Minimum Technical Competence (MTC) and National Occupation Standard (NOS) documents are the basis for the scheme.
Test reports are issued by registered and licensed air tightness companies who test buildings of different sizes and complexities. Temporary sealing of extraction units will be done by the tester; all test results will be noted, and a shortened form report will be written which will include the findings of the test. The organisation makes sure the report meets the company and government’s requirements.
AF Acoustics will ensure the test result is written in accordance with the test standard requirements, identify any deviations from the relevant standards within the report and check air tightness against target value. We will ensure the report correctly identifies the tester, customer, building and its address. Where applicable, we will identify pass or failure of your building and provide recommendations for any remedial action or improvement to the building if any further testing is required.
Before we arrive on site, ensure you have sent us the air permeability target and been through the checklist below and the ones we have sent you. This will greatly facilitate the process.
Air Leakage Pathway Checklist – Check will be done for visible leaks in the following places:
Air leakage is the uncontrolled flow of air through gaps and cracks in the fabric of a building (sometimes called infiltration or draughts).
This is not to be confused with ventilation. Which is the controlled flow of air into and out of the building through purpose-built ventilators that are required for the comfort and safety of occupants.
Too much air leakage leads to unnecessary heat loss and discomfort to the occupants from cold draughts.
At AF Acoustics, we will endeavour to help you identify air leakage/infiltration paths.
There are a number of methods we employ to do this, including:
In the vast majority of cases the first two methods are sufficient to identify the most significant air leakage paths along with our expertise we will be able to point our the problem areas should they arise. The air leakage areas will have to permanently sealed and the test repeated to reduce the air permeability of the building. Where problems are larger and sealing cannot be addressed on the day, the building may need to be re-tested at a later date.
A test certificate from The Air Tightness Testing and Measurement Association (ATTMA)
A testing procedure is to be carried out to comply with TSL1 for domestic or TSL2 for commercial. The test certificate will include sufficient information to describe the building tested e.g. location, type and size (the envelope area is an important component in calculating the air permeability and must be accurate) plus the design air permeability as well as the actual result. A testing procedure should be representative of the actual building performance.
An indicative result is available at the time of testing. Certificates can be issued within a day of testing.
If required, you can request all calculations including pre, and post environmental measurements, individual static pressures, envelope area breakdown, flow readings and calibration certificates at no extra charge.
Air permeability is essentially a function of the pressure difference between the inside and outside of the building and the air flow rate through the fan(s), necessary to produce a pressure difference. This is averaged out over the envelope area. The result takes account of environmental conditions.
The final air permeability at 50 Pa is based on a logarithmic graph of pressure difference and flow rate, the graph should:
These are aspects that the building control should check carefully if choosing to accept air permeability results from non-accredited testing bodies.
Most air tightness tests for domestic units and simple commercial units are carried out in 45 – 60 minutes. This time may be extended if the test fails and leakage paths are investigated. We will normally charge for a retest depending on how much work is to be carried out.
On larger commercial units, which require 1 large air test fan, air tests take 1 hour if all temporary sealing has been completed prior to starting the air test.
If complicated or very large buildings are being air tested with multiple fan units, allow up to 4 hours for the test and longer if investigations are required.
The envelope area is calculated from the drawings and verified on site. The envelope of the building is all the surfaces that separate the heated interior from the unheated exterior of the dwelling. This includes walls, floors and the roof.
Generally, this involves mounting a door profile and incorporating one or more electrical fans into an external door opening(s). Depending on their orientation, the fans can be used to pressurise or depressurise the building. The resulting difference between the external and internal pressure can be used to calculate the permeability of the building envelope (given that the envelope area is known).
This permeability is an indicator of how air tight the building is, and whether there are openings in the envelope. Generally, 10 differential pressure points are taken at different fan flows to establish an accurate result for the building. Our certified specialised software is used to establish an accurate Air Tightness Test result.
Our experts at AF Acoustics will provide a simple checklist for building preparation, which includes the following:
All building preparations should be made before our test engineers arrive on the site this will ensure a smooth testing process and increase your dwelling’s chances of passing the test the first time. We will seal all the vents ourselves.
For multiple dwellings it may also be necessary to agree on the test programme with the building inspector before arriving on site.
Where possible, it is helpful to accurately calculate the envelope area and confirm the fan installation arrangements based on architectural drawings before coming to the site.
For dwellings, sufficient information is required to identify the different dwelling types and the number of each such as General Arrangement/Site Plan and Schedule (including other important details such as variation in storey height or construction method).
For buildings other than dwellings, the approximate envelope area is the key factor for quoting. It is required to establish the necessary fan arrangement. This affects the time on site and potentially the number of people, and this can be calculated from drawings – floor plans and elevations.
The testing body may also need to identify the potential aperture(s) into which test equipment is to be installed. In some circumstances this may require additional time on site, extra people or customised templates.
Approved Document L states that Building Control can accept evidence from BINDT or ATTMA Registered testers. However, the BINDT scheme was closed down at the end of 2014, subsequent to the last revision of Approved Document L. Additionally, The Independent Air Tightness Testing Scheme (iATS) is an authorised Competent Persons Scheme created for companies (including sole traders and partnerships) that carry out Air Tightness Testing.
The common leakage sites are:
All pipe works within the kitchen and bathrooms
Our team of experts can support you through the following
Additional AF Acoustics services – including noise survey, sound insulation testing services noise impact assessments
Employing the services of a reputable and accredited air tightness testing consultant, such as AF Acoustics, can help identify and remedy potential problem details in a building design prior to and during construction.
The Air Tightness Testing and Measurement Association (ATTMA) is approved by Department for Communities and Local Governments (DCLG) and is listed in the Building Regulations as an authorised Competent Persons Scheme for air tightness testing.
As an ATTMA registered company, AF Acoustics is independently certified by ATTMA with a scope covering air tightness testing to the ATTMA Technical Standards (TSL1 & TSL2) and BS EN: 13829 (2001), demonstrating knowledge and understanding, which enables us to test both commercial and domestic developments in accordance with relevant building regulations.
Part L sets the energy efficiency standards required by the Building Regulations. It controls:
It also sets out the requirements for SAP (Standard Assessment Procedure) Calculations and Carbon Emission Targets for dwellings. In addition to insulation requirements and limitations of openings of the building fabric.
Part L also considers:
Building Regulations are administered separately in England, Scotland and Wales.
The objective is to measure the volume of conditioned air escaping through the building envelope via uncontrolled ventilation at an induced pressure difference of 50 Pa. A simplified process is shown below:
No. However due to the penalties occurred to the air permeability value of non-tested properties, every property is usually tested. We can test all dwellings, including domestic buildings, industrial units, warehouses, schools, hospitals, residential care homes, hotels, offices, and retail units.
All new buildings and dwellings should be tested, but there are some exceptions and they are explained below:
No. Air tightness testing applies to:
Air tightness is an important factor in assessing the overall carbon emission of a building via the appropriate calculation methodology:
When a building is air tight, the amount of fuel needed to heat it is reduced. This conserves fuel and reduces the carbon dioxide produced, thereby lowering carbon emission and energy bills.
If you are building a new domestic property or commercial property of a certain size, it will need to undergo air tightness testing. This assesses the building for ‘air permeability’, checking for air leakage through gaps, holes and other areas. The Government has SAP (Standard Assessment Procedures) in place for air tightness testing, setting standards buildings must comply with to be energy efficient.
All residential properties and non-dwellings properties over a certain size (with a floor area greater than 500 m2) must undergo air tightness testing. With larger developments, a sample number of the buildings must be tested, depending on the size and construction of the properties. However, in practice all dwellings are likely to be tested, as non-testing attracts a severe penalty.
In a property where air tightness is below the recommended standard, the following problems can occur:
AF Acoustics lead air tightness testing Specialist, Gerard is your first port of call for all air tightness questions enquiries and surveys.
