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. Air tightness testing became an integral part of building regulations for new buildings, commercial developments and revamped buildings in 2006 after Document L was reviewed.
Revisions were made to building regulations to address air leakages – a process where air escapes through any opening in the building, affecting its energy efficiency. We register our air tightness certificates with the Air Tightness Testing and Measurement Association (ATTMA), an organisation that encourages proper air leakage applications and promotes quality air tightness screening. We are dedicated and accredited air leakage testing service providers in Streatham 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. We provide air leakage testing in a professional manner by explaining the testing procedures and highlighting leakage areas in the building fabric. We also suggest long-term remedies based on the results of the tests. Our goal is always value for money and customer satisfaction. We are professionals and our services are of the highest 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. While the normal restrained movement of air all through a building is called ventilation, the unchecked movement of air through cracks and gaps in a building is air leakage; also known as draught or infiltration. Air leakage is uncontrolled ventilation. Air tightness testing is the approved method for gauging the entire air that has leaked through a building fabric. Once too much air escapes, heat reduction occurs, causing the temperature of the building to drop to a level that isn’t comfortable for those residing in it. Because the government is striving to scale back carbon dioxide discharge from new buildings, building rules now focuses on reducing air loss from the building envelope. This helps reduce 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. With the introduction of tougher regulations, building designs will often consider air tightness at the early stages of the construction process, ensuring attention to detail during construction to create an air-tight envelope. 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. It is also referred to as infiltration and is the opposite of ventilation which involves well managed circulation of air in a building. Because of the nature of air leakage, excessive air infiltration might occur in a building when the weather is windy and chilly. This results in loss of warmth and an unpleasant cold draughts. 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. 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. Once the atmosphere is cold and windy, unwanted chilly air infiltrates the building through gaps, leading to heat reduction. It doesn’t stop there. Warm, damp air within the building escapes the gaps in its envelope. The water vapour in the moist air condenses on the inner wall surface holes. After a while, it is absorbed into building materials and diffuses, causing potential structural problems. Wet wooden overlay or framing can decay, decreasing its durability.
Over time, any of these conditions can cause structural damage.
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.
These effects can be mitigated by controlling the circulation of air into and out of the building. An adequately installed air barrier reduces air leakage and condensation of water vapour on inner wall layers. Passive or active ventilation is required to reduce water vapour, moisture odour and pollutants.
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. Reducing air leakage reduces heat loss, which in turn reduces the amount of energy a heating system uses. 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. High levels of air leakage can lead to moisture ingress into the building fabric, resulting in expensive repair costs and potential health problems due to mould.
A building should ideally be air tightness tested early in the construction process and again at the end of the building project, although sometimes only the final check is carried out. The test results are used in SAP and SBEM calculations, this impacts the energy rating of new building. Individual property is not tested in a large residential development. The test is done on different types of houses within the area. This type of testing attracts a penalty of +2m3/h/m2, consequently, if the target result is 5m3/h/m2, a lower score of 3 would have to be attained.
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. Because selective testing does not conduct tests for all buildings, a tested building might have a much higher air tight rate than an untested building; making it unreliable. The 2m3/h/m2 penalty added to untested buildings makes the air permeability rate hard to achieve.
At AF Acoustics, our air tightness testing expertise has helped many home and business owners in Streatham. Our clients highly recommend us for the following reasons.
In Streatham, we have served many clients. The experience garnered from our years of service will help us meet your specific needs no matter the size or type of property. 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. Do you need trustworthy professionals who will provide great results in Streatham? Contact AF Acoustics today.
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.
We want to provide detailed air permeability testing in Streatham for you whenever you need it. Simply fix a convenient time for your building’s air permeability test. We offer responsive scheduling. We guarantee no delays or complications regarding scheduling.
AF Acoustics offers a professional and reliable service; we understand that our clients are keen to get their test results as quickly as possible, to facilitate this process we strive to deliver next-day turnaround on test certificates.
AF Acoustics offers competitive fees in Streatham. Since we’re a small business, we offer less expensive air permeability testing and render high quality services.
Regardless of the size, type, or complexity of your domestic or commercial building in Streatham, we can provide you with air tightness testing, carried out by an experienced and professional air tightness tester and issue you a certified ATTMA certificate. You can find out how much uncontrolled ventilation your building has by testing it for air leakages. 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.
Approved Document L1A and L2A requires that buildings know their air permeability rates by taking the air leakage test. 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. 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. To limit exfiltration and infiltration, the law requires that domestic buildings take air leakage tests. The buildings must be energy efficient and signed off by building control in Streatham. For commercial constructions, air pressure tests result in a better environment for workers and customers. In addition, you get lower heating and cooling costs. A comfortable environment results in a higher productivity rate.
Since Approved Document L was reviewed in 2006, building regulations have demanded that new and rehabilitated constructions conduct air tightness test. Air tightness is also called air leakage rate or ‘air permeability’ 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. Part L of the Building Regulations requires that all commercial buildings greater than 500m2 undergo air tightness testing and a selection of residential buildings in a development be tested. To adhere to Part L, make sure your building’s air permeability rate is not greater than 10m3/h/m2. Air leakage affects the building’s energy performance and is required to meet Building Regulations Part L and measure up to the standard for low carbon buildings.
We can complete all your Part F and Part L testing requirements. We deliver quality air permeability and extract fan flow rate testing, and also recommend skilled experts who will handle your water calculations, SAP calculations and Energy Performance Certificates.
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. Examining, documenting and submitting reports of extract fans’ test can be done using three methods. We use a vane anemometer, which is the third method called the minimum benchmark method, to conduct extract fan flow rate tests.
Air Tightness Testing has different tiers, depending on how complex a building is and its size. Find them below: A single blower door fan is used for air tightness testing for single buildings and smaller non-dwellings not more than 4000m3. Air tightness testing for dwellings more than 4000m3, except big phased handover/zonal and high rise (LCHR) constructions is done. Third Level – Testing is done for large high rise and phased handover buildings.
The measurement of air emitted by a building is tested to determine air permeability rating. The test results are inscribed as m3/h/m2 – (m3 per hour) per square metre. Document L1A of Building Regulations declares air leakage testing to be mandatory. The carbon discharge requirement for all buildings reduces the air permeability rate target. The required rate can be found in a building’s design-stage SAP assessment SBEM. An excessive amount of air leakage results in greater energy expenses, heat reduction and carbon dioxide emissions.
Air leakage testing is the measurement of uncontrolled ventilation from a building’s fabric. The test results are inscribed using m3 per hour per square metre. Air tightness testing is required by Building Regulations. The test results have a limit; they shouldn’t be higher than 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. Air leakage causes heat loss, increased energy bills, greater CO2 emissions, and an uncomfortable atmosphere for inhabitants due to draughts.
We provide smoke shaft tests to make sure it is air tight enough to let the automatic opening ventilation work optimally when it’s installed and commissioned. 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. 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. We’re committed to automatic opening vents builders’ target for air permeability. This enables the vents to work efficiently. Fans are placed in the smoke shaft to conduct an air tightness test. Then the openings are sealed off in all its parts so that the shaft can be thoroughly examined. Smoke shaft tests occur before installing and commissioning automatic opening ventilation.
The mandate to construct well insulated and air tight buildings, has made it crucial for satisfactory, enhanced and balanced ventilation systems to be installed. 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. 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.
An air tightness test measures the extent of air leakage 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. The only satisfactory way to show that a building fabric is airtight is to detect and measure leakage paths within the building fabric.
At least 20% of different kinds of dwellings in a development have to be tested, according to new regulations; but the reliability of the sample from this type of testing is determined by the types of buildings in the development. 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 require the drawings (plans and elevations) and target air permeability requirements of your building before taking the test. The test engineers would like to have the information needed for the test before coming to your development. Our air leakage test is done between 30 and 60 minutes, and the wind speed is a maximum of 6m/s. An air tight environment should be created in your building before the test to ensure optimal results. Do the following:
We take the building envelope calculations before the test. The building envelope is the surface area of the thermal boundary of the building. The measurement is obtained from the construction drawings, and put in our calculations to conduct the test.
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 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 its insulation in the ceiling and there’s a huge space between the insulation and rafters.
A warm roof has the insulation running along the pitched roof rafters with an air barrier normally running parallel along the inside face of the insulation. The envelope area is the boundary between the internal environment and external environment (adjacent buildings), and can be found on the insulation’s warm part.
Measure the weather conditions. Check the temperature, barometric pressure and wind speed. Connect a fan to an aperture within the construction envelope. For example, the door. Fix the instrument for testing. Calculate the air flow volume through the fan which equates to the air leakage. Slowly raise the fan speed from 20-25Pa to 55-60Pa. Record pressure differences across the building at each fan speed.
We can determine where air leakage is occurring through our test procedure. Once the test has been completed, we crosscheck the data and send a report to you. If the test fails, we will advise you about corrective measures. 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: The occupants will pay less for heat because less heat is lost and they won’t need equipment with high heating capacities. Your ventilation system will operate in a better way Lower probability of mould because moist air won’t condense in the openings in the building envelope. Fewer draughts, causing more comfort Our air leakage tests are conducted according to building regulations and targets, whether we’re testing a small dwelling or big commercial development. We provide air tightness testing, consultancy, design reviews and support services on all buildings, both dwellings and non-dwellings in Streatham. 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 any new building must undergo an air pressure test, according to present 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 are constructing a dwelling the Approved Document L1A states that you must perform an air pressure test. 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 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. 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. Non-Dwellings and residential buildings are required to test for air leakage. 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.
ATTMA has a scheme for air leakage test organisations, which commenced in January 2015. The scheme was approved by the government and is stated in Technical Standard L1 and L2. Minimum Technical Competence (MTC) and National Occupation Standard (NOS) documents are the basis for the scheme.
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. This is done according to the testing organisation’s procedures and Building Regulation standards.
AF Acoustics will make sure the result is written in line with test requirements, detect any part of the test that is not in line with the standards required and check actual air tightness against required rate. Clients’ test reports contain their names, construction, address; the tester’s name is also included. 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.
Please send your design air pressure figure to us and go through the list below before we arrive at your site.
Air Leakage Pathway Listing – You must ensure the following are properly sealed and don’t have any openings.
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.
