Air tightness testing, also known as air leakage testing or air permeability testing, establishes the rate at which air flows out of gaps in a building 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.
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. We are dedicated and accredited air leakage testing service providers in Wadhurst and we are available to provide you with testing services whenever required. We also provide Part F mechanical extract fan flow rate testing, assessments and consultancy services.
Because we are ATTMA members, any air tightness certificate we issue shows that the construction has met building regulation standards. Not only do we test the air permeability of your building, we describe the procedure in a professional manner and advise you on problem areas discovered during the evaluation. AF Acoustics provides services that are cost effective and of high standard.
Air tightness testing is a technique whereby a newly constructed building is evaluated and the quantity of air leaking through is measured. 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 tightness testing is the recognised method used to measure total air lost through leaks in a building fabric. This is often referred to as uncontrolled ventilation (draughts). Too much air leakage leads to unnecessary heat loss and discomfort for the occupants. The government aims to lessen the quantity of air flowing from newly built buildings. Therefore, regulations have been put in place to reduce uncontrolled ventilation from the building envelope, sustaining the right temperature conditions without using so much fuel. 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. The introduction of tougher regulations has led to the construction of high-quality buildings. Building designs employ air tightness procedures from the early part of construction, creating a building that has adequate air tightness built into its design. 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. 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 testing plays a significant role in the energy-saving efficacy of properties. With air tightness testing, you can be sure that the building has met the stipulated targets used for energy calculation and air tightness. All commercial buildings over 500m² and new buildings in England and Wales are mandated to test for air tightness and permeability, according to the 2006 Building Regulations.
Air leakage leads to heat reduction. During windy or cold weather, the infiltration of uncontrolled air through cracks in a building envelope occurs, leading to heat reduction. As cold seeps inside, warm moist air escapes through the cracks and gaps in the building. Some of it settles within the building’s fabric. 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. Wet wooden framing or sheathing can rot and break down, diminishing its strength.
Over the years, these problems can damage the building’s structure.
Other damages that can occur are cold homes which make occupants uncomforta-ble, increase in heating bills to make the internal temperature warmer, and more carbon dioxide discharge since additional heat is required.
The most effective method of lessening the damage caused by moisture is to control the flow of air into and out of the building. Air leakage and vapour diffusion are minimised when barriers are installed. Proper ventilation, whether active or passive, is critical in expelling undesirable damp scents, water vapour and polluting substances.
Climate change caused by carbon dioxide emission is an environmental hazard that government is trying to curb. Energy performance and air tightness is a key part of this plan. Environmental change caused by carbon dioxide emissions and global warming is partly aided by the burning of fossil fuels to generate heat. The best way to reduce the quantity of fossil fuel burnt is by stopping air leakage which reduces heat loss. 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. The best advice is to “Construct tightly, ventilate properly”. Excess air leakage leads to moisture in the building envelope, causing large repair expenses and medical issues because of mould.
Best practice dictates that you complete an air tightness test early in the build process, and then again after the construction process is completed; although not all builds have the first test phase. Newly completed constructions’ energy ratings can be influenced by the test results, as they are used in SAP and SBEM calculations. For big residential developments, the test is not required for each house. A group of diverse buildings are picked for the test. 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.
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. It’s better to test each property because selective testing does not give a realistic picture of individual buildings. Besides, air permeability rates are difficult to achieve for untested buildings in such areas due to the +2m3/h/m2 penalty.
At AF Acoustics, our air tightness testing expertise has helped many home and business owners in Wadhurst. 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 Wadhurst guarantees we have the expertise to satisfy your needs regardless your unique circumstances, type or size of property. Our qualified air tightness testing professionals will work around your schedule, so they fit into your project seamlessly, providing a quality service as conveniently as possible. 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 with ATTMA, a professional body that focuses on high quality air tightness testing and air permeability applications. This means our services are endorsed by the leading air leakage testing body in the UK.
We want to provide detailed air permeability testing in Wadhurst for you whenever you need it. Pick a time that is convenient for you in our responsive scheduling options. We guarantee that there will be no delays or difficulties.
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.
AF Acoustics offers competitive fees in Wadhurst. Since we’re a small business, we offer less expensive air permeability testing and render high quality services.
We conduct air permeability tests on residential and commercial buildings of all sizes and types. After the test, an ATTMA certificate is given to you. The best way to determine how much air seeps through a building’s fabric is through air permeability testing. 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 demands that buildings take tests for air leaks. Although your building is required to have a rating result of 10m3/h/m2, the actual result might have to be lower than that due to carbon emission requirements. You can find the required air permeability rate of your building in its design-stage SAP assessment or SBEM. 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. Exfiltration/infiltration of air is caused by the difference in air pressure inside and outside the building. Lower pressure occurs as warm air rises and brings air inside through any available opening. Air permeability testing is a legal requirement for constructions in Wadhurst. This way, they can have high energy performance, meet building regulations requirements and get signed off by building control. For commercial constructions, air pressure tests result in a better environment for workers and customers. Heating and cooling expenses are also reduced and the environment is more productive.
Air tightness testing has been a mandatory part of the Building Regulations for new build and refurbishment projects since Approved Document L was revised 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. You can exceed the CO2 discharge and Building Regulations target and raise your building’s energy performance by testing for air leakage.
We will help you with all your Parts L and F requirements. 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.
Get the mechanical extract fans tested for flow rate. This is what Building Regulations Approved Document F requires. Your building won’t be signed off until Building Control Body (BCB) has been presented the results of the test. You can test, document and report the test of your building’s extractor fans in three ways. Use method 3 – the minimum benchmark method, which tests extractor fans with vane anemometers. This is our testing procedure.
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 Three: At this level, tests for the air pressure of high rise (LCHR) buildings and phased handover/zonal buildings.
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. Part L1A of Building Regulations stipulates that such tests be conducted. Your building may need a lower rate to meet the CO2 discharge target. The design-stage SAP assessment SBEM of a construction records its required air permeability rate. Uncontrolled ventilation can cause several problems. They are: infiltration of cold air, reduction in heat, more CO2 emission and higher energy costs.
Air pressure testing involves the calculation of air escaping through the openings in a building. The result is expressed as a quantity in the form of air pressure (m3 per hour) per square metre of building fabric. Air tightness testing is required by Building Regulations. The test results have a limit; they shouldn’t be higher than 10m3/h/m2. In order to comply with the SAP assessment, it may be necessary to achieve a lower air permeability rate. You can find the required air permeability rate of your building in its 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.
We undertake smoke shaft integrity testing to confirm that the shaft is sufficiently air tight in order to allow the automatic opening ventilation to perform as required when it is fitted and commissioned. Automatic opening vents help storey buildings dispel smoke when there is a fire. For the vents and fans to operate at the expected level, the smoke shaft must be air tight to create a difference in air pressure and give emergency services when needed. To ensure that automatic opening ventilations work properly, their manufacturers have placed an air permeability target for them which we work towards. An air pressure test is conducted using a fan installed in the shaft. The openings for ventilation grilles and extract points on each floor are closed so that the state of the shaft itself is known. Smoke shaft tests occur before installing and commissioning automatic opening ventilation.
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 are able 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. Part F Building Regulations also require standard intermittent extractor fans in new buildings (such as bathroom and kitchen extractors) to have their air flow rates measured on site and the results submitted to the building control body before completion.
Air tightness test determines the level of air permeability in a building. Improving the air tightness of a building not only enhances the comfort of the occupants, but can also increases the building’s energy efficiency.
It is difficult to notice unwanted openings in a building envelope. They might be blocked by the internal finishes. To ensure that the air tightness of a building is optimal, gaps and spaces in the building have to be found and measured.
With residential buildings in an area, new building regulations demand that a minimum of 20% be measured for air leakage. Consistent samples are determined by the quantity of the different types of houses present during the construction of the project. Buildings that don’t undergo the test are penalised. All dwellings in a development should be tested to ensure optimum air tightness.
Our test engineers would like to see the drawings (plans and elevations) and design air permeability requirements of your building before taking the test. We would like to know the requirements and the building envelope’s size prior to testing. The tests take 30 – 60 minutes, and wind speed does not surpass 6m/s. In preparing the site to create an air-tight environment:
We conduct building envelope calculations prior to the test. The building envelope is the surface area of the thermal boundary of the building. The calculations, which are extracted from the drawings, are fed into our estimations when testing your building for air leaks.
Air permeability is calculated at air leakage rate per square metre of envelope area. In relation to air permeability, the air envelope area is the total area of the measured part of the building without subtracting from the area of the junction of internal walls, or floors and ceilings. The envelope area of a terraced house includes the party walls while that of a flat in a multi-storey building includes shared ceilings, walls and floors.
Air exchange rate is vital to ventilation design but it isn’t used as the determinant of the actual design or calculation. The calculation of residential ventilation rates is dependent on the area of the homes and number of occupants.
It is important to make sure the roof area and ground floor area of a building are equal. 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.
In a warm roof, an air barrier is inside the insulation which runs on the pitched roof rafters. The envelope area is the barrier between the conditioned space in the insulation and the unconditioned space outside.
To get the building ready, close and secure all internal doors, windows, Temporarily seal vents and smoke vents. Also fill drainage traps.
Evaluate the weather (barometric pressure, wind speed and temperature) Fix a fan to an aperture, usually the door, in the building. Fix the instrument for testing. Note the air flow volume from the fan. This is the same as the air leakage from the building envelope. Slowly raise the fan speed from 20-25Pa to 55-60Pa. Record how the air pressure differs at each fan speed.
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 Pressure Testing & Compliance
Making sure your building is air tight and has adequate ventilation, be it natural, mechanical, or a combination of the two, will aid your comfort. Find below the benefits: Your heating expenses are less because heat doesn’t escape through a permeable building, and you won’t require appliances with more heating capability. The ventilation system will operate optimally Lower probability of mould because moist air won’t condense in the openings in the building envelope. Infiltration of air is reduced and the inhabitants are more comfortable. From the smallest to biggest building or development, we adhere to Building Regulations Part L and Building Standards. We provide air tightness testing, consultancy, design reviews and support services on all buildings, both dwellings and non-dwellings in Wadhurst. We also provide cost-effective, local service that complies with all relevant Building Standards.
When constructing a new building, it should be built air tight, as stated by Building Regulations – Approved Document L1A. Reduced power usage and fuel conservation are important; that’s why the rule was put in place. Part L1A has demanded that all new dwellings be tested for air leaks in line with other regulations.
During air leakage tests, there are technical standards that must be used. This was mandated by ATTMA – Air Tightness Testing and Measurement Association–to align with building regulations and other rules. This Technical Standard provides detailed guidance and clarification of BS EN 13829:2001: “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”, in order to ensure consistency by testing companies.
If you are constructing a dwelling the Approved Document L1A states that you must perform an air pressure test. For developments of two or more dwellings, an air leakage test should be carried out on the three units of each dwelling type; or 50% of all instances of that dwelling type. For developments where no more than two dwellings are constructed, it may be possible to avoid the need for any pressure testing by using an assumed value of 15m3/h/m2 within the DER/TER calculations. An SAP assessor can decide which buildings can use the assumed value successfully. The required process for testing buildings for air tightness has been declared in ATTMA TSL1 for occupied buildings and ATTMA TSL2 for unoccupied ones. Air leakage testing is compulsory for residential areas 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.
Most competent air pressure testing companies go through the ATTMA scheme, which began in January 2015, etence. The scheme is endorsed by the government and recognised by approved documents L1 and L2 of building regulations. Its basis is the National Occupation Standard (NOS) and Minimum Technical Competence (MTC) documents standard for testing and essentials for testing knowledge.
Air tightness reports are issued by accredited firms that carry out air permeability tests on buildings of different sizes or complexities. The testing companies seal extraction fans. After the test has been completed, they record test findings and results in a report. The report is in line with the company’s testing process set by government regulations and all relevant governing bodies.
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 it’s needed, we will identify if your building passed or failed the test and suggest ways to repair the building envelope before a retest is done.
Please send your design air pressure figure to us and go through the list below before we arrive at your site.
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.
