Air tightness testing, otherwise called air pressure testing or air leakage testing, is the measurement of the outflow of air from a building’s fabric. 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.
The energy performance of a building can be affected by air leakage. To address this problem, alterations to building regulations have been made. 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. AF Acoustics, a licensed air tightness testing company, is available to provide testing services at your request. Our address is Crooked-Billet. You can also call or email us for any of these services:
As registered members of the ATTMA, our air tightness certificates are accepted as proof of building regulations sign-off. 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. Our customers get greater value for money spent, and our testing services are of superior quality.
Air tightness testing is carried out to determine the volume of air escaping from holes in a building fabric. Air leakage and air pressure are also used in place of air tightness. Air leakage should not be confused with ventilation. Also called draughts or infiltration, air leakage is unrestrained movement of air through holes in a building fabric, while ventilation is the restrained and planned movement of air. Air tightness testing evaluates the complete air leakage a building has in every gap available. The air leakage is known as uncontrolled ventilation. When too much air leaks through a building’s fabric, heat loss occurs, making the occupants uncomfortable. Air leakage from buildings causes heat loss, more energy is then used to keep the building warm, this is a cause of excess CO2 emissions. This has resulted in regulations which are centred on decreasing air leaks from the building fabric, therefore lowering CO2 emissions. Air tightness testing is a crucial activity that
The building regulations have made air tightness part of the building’s design from the beginning of the construction. This ensures that the fabric of a building is air tight. Incorporating this at the beginning of the construction process makes the development more cost effective and energy efficient.
Air leakage is where air enters and leaves a building uncontrollably through cracks and holes in the building fabric. Also known as infiltration, it is different from ventilation, which is air that enters a building in a controlled manner. 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 and a dwelling’s energy efficiency are intertwined. Testing is needed to verify that air tightness levels used in the building’s energy calculations align with the targets required by the law. In 2006, air tightness of newly constructed buildings and non-dwellings with a floor area over 500m² became compulsory in England and Wales.
Air leakage causes heat loss. During windy weather, cold air infiltrates a building through the openings in its fabric. This results in heat loss. It doesn’t stop there. Warm, damp air within the building escapes the gaps in its envelope. The warm air is filled with moisture, which hits the inner wall surface and condenses. Moisture is sucked into the building material, and this can lead to serious structural issues. Wooden sheathing or overlay becomes wet, making it weak.
The building becomes structurally damaged as time goes on.
Other impacts include:
These effects can be mitigated by controlling the circulation of air into and out of the building. Adequately installed air barriers minimise air leaks and the probability of vapour condensing and diffusing into the building’s structure. Passive or active ventilation is required to reduce water vapour, moisture odour and pollutants.
The energy performance of a building is determined by how air tight it is. Energy performance affects CO2 released from buildings. As a result, air tightness testing is a method government has devised to regulate climate change. Fossil fuel is burnt to heat up a building. This leads to a discharge of carbon dioxide which increases global warming. When air leakage is controlled, heat loss and energy used by the heating system are reduced. Individuals living in buildings with high levels of air leakage may have medical problems. Houses. Low ventilation and uncontrolled air leaks result in mould growth and moisture which can cause potential health issues. To “Construct tight, ventilate right” is the best practice. Excess air leakage leads to moisture in the building envelope, causing large repair expenses and medical issues because of mould.
It is best practice to complete an air tightness test early on and then again at the final stage. 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. Selective testing has a penalty of +2m3/h/m2. If target score is 5m3/h/m2, air tightness test score will have to be 3m3/h/m2.
The assessed air permeability of an untested residence is a calculation of the average test score of the same kind of dwelling in the development, increased by 2m3/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.
Numerous businesses and home owners have been aided by AF Acoustics air tightness testing proficient skills in Crooked-Billet. Our clients highly recommend us for the following reasons.
Our experience in serving diverse customers in Crooked-Billet is proof of our ability to satisfy your requirements no matter the size and type of building, or your circumstance. We’ll work with you to carry out our tests and consultations at times that are convenient to you, delivering an exceptional quality, convenient service. Our knowledgeable and dependable air testing experts will provide lasting solutions to your problem. Call AF Acoustics for your air tightness testing.
We are registered members of the Air Tightness and Measurement Association (ATTMA). ATTMA encourages proper air leakage applications and promotes quality air tightness screening, and has recognised our impeccable professional services.
Our comprehensive air permeability testing in Crooked-Billet is available. Pick a time that is convenient for you in our responsive scheduling options. We won’t make you wait or make the process complicated.
AF Acoustics offers trustworthy and expert services. We know that clients want to receive their test results quickly. As a result, we endeavour to deliver test certificates by the next day.
AF Acoustics offers competitive fees in Crooked-Billet. Since we’re a small business, we offer less expensive air permeability testing and render high quality services.
Whatever the type and size of a domestic or commercial building in Crooked-Billet, 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 result of the air leakage test is expressed as a quantity in the form of The test results are described as m3/h/m2 – (m3 per hour) per square metre. of a building envelope.
Air leakage testing is a requirement of Approved Document L1A and L2A. The maximum air permeability rate is 10m3/h/m2. The carbon discharge requirement for all buildings reduces the air permeability rate target. This target can be found in a building’s design-stage SAP assessment or SBEM. With air leakage comes heat loss, greater CO2 discharge, draughts, thermal bypassing and wind washing and poor energy performance. Warm air within a heated building rises and lowers the pressure at the building’s base to draw in air through the openings in the building fabric, leading to exfiltration or infiltration. In Crooked-Billet, the law demands that all new buildings be tested for air pressure before they can be approved and signed off by building control. This enables dwellings achieve energy efficiency standards. For your commercial building, air tightness testing will ensure your staff and clients are in a comfortable environment. This increases the company’s productivity and lowers heating and cooling expenses.
Air tightness testing is a Building Regulations obligation for new buildings, commercial developments and revamped buildings. This was put into effect in 2006 after Document L was reappraised. Air tightness is referred to as air permeability or leakage rate. Although not always seen, air leakage can occur through any gap, space or crack in a building’s fabric. It is compulsory for all commercial buildings with a gross area greater than 500m2 and a representative selection of domestic buildings to undergo air pressure test, as stipulated by Part L of the Building Regulations. Part L has also set a maximum air permeability target rate of 10m3/h/m2, but a building usually needs lower levels. You can exceed the CO2 discharge and Building Regulations target and raise your building’s energy performance by testing for air leakage.
We will ensure that you exceed all the Parts L and F standards. First, we provide extract fan flow rate and air leakage testing. Then we put you in contact with competent professional to work on your Energy Performance Certificates, SAP and water calculations.
Approved Document F of the Building Regulations requires that all mechanical extract fans in new dwellings be subjected to a flow rate test. Evidence of this test must be passed to the Building Control Body (BCB) as part of their sign-off procedure. There are 3 available methods for examining, recording and reporting the testing of extract fans. We use a vane anemometer, which is the third method called the minimum benchmark method, to conduct extract fan flow rate tests.
Here are the descriptions of the ways air permeability can be tested: 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. Level 3: Air Pressure Testing for LCHR buildings, phased and zonal handover buildings is carried out.
Air pressure testing, involves the calculation of air escaping through openings in a building. The result is expressed as a quantity in the form of m3 per hour, per square metre of building fabric. Air pressure testing is compulsory, according to Approved Document L1A. A lower air permeability rate might be needed due to carbon emission requirements. The required rate can be found in a building’s design-stage SAP assessment SBEM. Uncontrolled ventilation can cause several problems. They are: infiltration of cold air, reduction in heat, more CO2 emission and higher energy costs.
Air leakage testing is the measurement of uncontrolled ventilation from a building’s fabric. The result is written as m3/h/m2 – (m3 per hour) per square metre of building envelope. Part L2A of Building Regulations has demanded that such tests be conducted. Each building tested must achieve a maximum air permeability rate of 10m3/h/m2. In order to comply with the SAP assessment, it may be necessary to achieve a lower air permeability rate. The design-stage SAP or SBEM assessment of a construction records its required air permeability rate. Too much air leakage leads to heat loss (and consequently, higher CO2 emissions) and draught.
To ensure that the auto opening vent will perform optimally when fitted and commissioned, we test the smoke shaft to verify its air tightness. When there is a fire, the auto opening vents play an important part in expelling smoke in multi-storey 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’re committed to automatic opening vents builders’ target for air permeability. This enables the vents to work efficiently. The shaft is tested for air permeability by using a fan that is fixed inside it. The usual openings are closed off too so that the shaft’s integrity can be determined. Once the test is completed and successful, the automatic opening vents are installed.
The requirement for air tight buildings that are properly insulated has brought about the need for ventilation systems that are adequately installed and function at an optimal level. We have the capacity to test extraction rates. This test is required by law and it enables a building have a high-quality ventilation system that is efficient and removes pollutants and odours while limiting humidity in rooms, especially in kitchens and bathrooms. Another of such targets, as stated by Part F, is to have the standard intermittent extractor fans, like kitchen and bathroom extractors, in new constructions measured for air flow and results given to Building Control before the construction work is completed.
When a building is checked for the quantity of air flowing through the gaps in the fabric, it has undergone an air tightness test. If the rate of air pressure is good, the energy performance of a building will be high and the inhabitants will be comfortable.
Causes of excess air leakage are often hard to detect. These openings might not be seen because of the internal finishes that have been fixed. To ensure that the air tightness of a building is optimal, gaps and spaces in the building have to be found and measured.
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.
Send the drawings of your dwelling (plans and elevations) and its target air permeability requirements to our test engineers. An Air tightness test can be done in 30 – 60mins. Wind speed should not exceed 6m/s. Test engineers need to know the size of a building envelope and requirements before coming to the site. Making your building ready by ensuring it has an air tight environment will involve:
We undertake building envelope measurements before getting to the dwelling for the test. The building envelope, is the physical barrier between the exterior and interior of a construction. The building envelope calculations are taken from the drawings and used for our air tightness testing.
Approved Document L1A Conservation of Fuel and Power in New Dwellings (2010) defines air permeability as “air leakage rate per hour per square metre of envelope area at the test reference pressure differential of 50 pascals (50n/m2)” and envelope area as “the total area of all floors, walls and ceilings bordering the internal volume that is the subject of the pressure test. This includes walls and floors below external ground level. Overall internal dimensions are used to calculate this envelope area and no subtractions are made for the area of the junctions of internal walls, floors and ceilings with exterior walls, floors and ceilings.”
The air change rate is important in designing a ventilation system, however, it is hardly a part of the actual design. Residential ventilation rates are measured based on the number of inhabitants and area of residence.
The area of the roof and ground floor should be the same. A cold roof has its insulation at the ceiling level, with space between the insulation and rafters.
In a warm roof, the main insulation is placed below the roof covering. The envelope area is the barrier between the conditioned space in the insulation and the unconditioned space outside.
Measure the weather conditions. Check the temperature, barometric pressure and wind speed. Place the fan on an aperture within the building envelope. Ensure all the testing equipment is ready. Using the fan, measure the air flow volume, from the building fabric. Raise the fan speed from 20-25Pa to the highest speed of 55-60Pa. Record how the air pressure differs at each fan speed.
Our air leakage measurement involves picking out the gaps where air leakage takes place, recording the test information, sending results to customers in a technical report and advise clients on repair methods in the case of a test failure. Testing for Air Tightness & Meeting Part L Standards
A low leakage building that is properly ventilated, whether natural, hybrid or mechanical, is very beneficial. The benefits are: Lower heating bills due to less heat loss, with potentially smaller requirements for heating and cooling equipment capacities Better ventilation system Lower levels of mould due to less moisture collecting in gaps and cavities. Fewer draughts, causing more 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. Not only do we provide services that meet building regulation targets, when you employ our services, you’ll save money and spend less in the long run. We test for air permeability, provide consultancy services and support services and review the designs of all buildings, whether domestic or commercial, large or small.
All new buildings, residential or commercial, must be air tight, according to Approved Document Part L1A of Building Regulations (2010). Less fuel and power are consumed by buildings. The dwelling should be tested for air permeability in line with existing building standards, as stipulated by Approved Document Part L1A.
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. 50% or 3 units of each dwelling type should undergo an air leakage test in the case of an area with two or more dwellings. If there are no more than two new dwellings, using an assumed value of 15m3/h/m2 in the DET/TER calculations might exempt them from air tightness testing. Your SAP assessor will be able to confirm if this is the case for your dwelling. A testing procedure required by Building Regulations is expressed in ATTMA TSL1 for dwellings and ATTMA TSL2 for non-dwellings. Air tightness tests are to be carried out on all residential developments (all the buildings or a selected group) and all certain Non-Dwellings. Non-dwellings with a typical floor area less than 500m2 may be exempt. Where testing is not carried out, an assessed air permeability of 15 m3/h/m2 must be used in calculations.
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. It mirrors the operation standards and skill requirements set by the National Occupation Standard (NOS) and the Minimum Technical Competence (MTC) document.
Air leakage test reports are given by authorised organisations that test different buildings. Extraction fans will be sealed temporarily; the results of the test are recorded in a short report. 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. Our reports correctly note the client, air tightness tester, building and 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 our test engineers arrive at the site, please adhere to what is written below and send the required air tightness target of your dwelling that is in the design to us.
Air Leakage Pathway List –Ensure you thoroughly check the following equipment. Fill up drainage traps. Here are the pieces of equipment to cover, fill or seal:
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.
