Air tightness testing determines the quantity of air coming out of cracks in a building. It is also known as air permeability testing or air leakage 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.
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 certificates for air tightness testing are registered with the Air Tightness Testing and Measurement Association (ATTMA), a professional body that focuses on high quality air tightness testing and air permeability applications. We are dedicated and accredited air leakage testing service providers in Lower-Edmonton 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.
As registered members of the Air Tightness Testing and Measurement Association, our air leakage test certificate is accepted as evidence for Building Regulations sign-off. 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. It can also be called air pressure testing or air leakage testing. Air leakage, also known as infiltration or draught, allows air to pass through unwanted leaks in a building; unlike ventilation where the air inside and outside of a building and its flow from one end to the other is controlled. Air leakage is uncontrolled ventilation. Air tightness testing is the approved method for gauging the entire air that has leaked through a building fabric. Unrestrained air movement leads to heat reduction, making the inhabitants of the building 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 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. Understanding this at an early stage can make a build cost-effective, of high quality, and energy efficient by minimising uncontrolled air leakage.
Air leakage is uncontrolled air movement in a building due to cracks. Air leakage is the uncontrolled movement of air into and out of a building through gaps and spaces in the building’s fabric. When the circulation of air is properly monitored and bridled, ventilation has occurred. Another name for air leakage is infiltration. Once the atmosphere is windy, draughts infiltrate the building through holes in the fabric, leading to heat reduction and discomfort. How do you know if a building is energy efficient? By testing its air permeability. This lets the occupants know if the building meets standard air-tightness requirements. In England and Wales, air tightness testing has been obligatory since 2006. All new dwellings and non-dwellings over 500m² are to be tested for air permeability.
Heat loss within a building can be caused by air leakage. When the weather is cold and windy, unwanted air seeps into a building through the holes and cracks in its fabric, causing heat loss and discomfort. Once there’s infiltration, exfiltration will occur in another part of the building. Warm, moist air seeps into cool cavities in the building’s fabric. Once the moist air reaches the colder internal layer of the wall structure, the vapour in it condenses and forms droplets of liquid, which drawn into building materials and can potentially start a multitude of structural problems. There could be a decrease in the toughness and solidity of wet wooden covering due to rot.
Over time, any of these conditions can cause structural damage.
Other effects of air leakage are:
The key to minimising the damage potential of moisture is effectively managing the flow of air into and out of the building. The potential of vulnerable wall structures to absorb condensed moisture is reduced when air barriers are properly installed and uncontrolled air flow is reduced. Correct ventilation is important, whether it is passive or active, to remove water vapour, unwanted moisture odour and pollutants.
Air tightness is an important factor in a building’s energy efficiency and is part of government’s plan to battle environmental change by regulating the energy performance of buildings. Environmental change caused by carbon dioxide emissions and global warming is partly aided by the burning of fossil fuels to generate heat. The best way to reduce the quantity of fossil fuel burnt is by stopping air leakage which reduces heat loss. Properties with uncontrolled air leakage also cause health issues. A building with poor ventilation and high air permeability is conducive for moisture and mould growth which can affect the inhabitant’s health. Best practice advice is to “Build tight, ventilate right”. Air leakage causes infiltration of moisture into the building envelope, leading to health issues and high repair costs.
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. Newly completed constructions’ energy ratings can be influenced by the test results, as they are used in SAP and SBEM calculations. It’s not a necessity to perform tests on each property, rather, different kinds of houses are selected and tested. 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.
If your building has not been pressure tested, its assessed air permeability would be the average score of buildings like yours in the area +2m3/h/m2 at 50 Pa. Selective testing is not recommended because: i.It is quite tough to achieve the lower air permeability rate set for untested dwellings. ii.The proper air tightness rate for each building in the development cannot be attained, as only some underwent air tightness testing; a tested building might be much tighter than an untested one.
With AF Acoustics, homes and businesses in Lower-Edmonton have been getting quality air tightness testing. Because of the following guarantees of working with us, we are highly endorsed by our clients.
In Lower-Edmonton, 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. Our personnel will use their expertise to provide lasting solutions. Contact AF Acoustics in Lower-Edmonton –the right team for your building.
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.
You can access our complete air tightness test in Lower-Edmonton at anytime. We offer responsive scheduling options. You can schedule for air tightness testing at your convenience. We won’t make you wait or make the process complicated.
Our customers are eager to get their test results. AF Acoustics, which provides reliable, competent services, strives to issue test certificates on the next day.
Save money by paying lower rates at AF Acoustics. As a business with low overheads, we’re able to give you one of the best air leakages testing services in Lower-Edmonton at reduced costs.
All domestic and commercial buildings in Lower-Edmonton can be tested by AF Acoustics, no matter how complex they are. The air tightness tests are carried out by competent testers and you will be issued an ATTMA certificate. Air tightness test checks the extent of uncontrolled air moving through openings in the building envelope. The result 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 building fabric.
Air leakage testing is required by 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. Several problems are caused by uncontrolled ventilation. They are:
Infiltration/exfiltration is the effect of air pressure difference. Warm air rises while cold air falls. The warm air within a building rises and air pressure at the base falls; this results in air coming in through doors, windows and leakage points. 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 Lower-Edmonton. For your commercial building, air tightness testing will ensure your staff and clients are in a comfortable environment. It will also help you reduce the cost of maintaining heating or cooling in your commercial building, making it more productive.
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 also called air leakage rate or ‘air permeability’ rate. Although not always seen, air leakage can occur through any gap, space or crack in a building’s fabric. 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. The maximum air permeability rating allowed is 10m3/h/m2, but your building might need a lower rating ts. Air leakage is vital to a building’s energy efficiency and is needed to meet Building Regulations Part L and carbon emission standards.
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. Building Control Body (BCB) has made a presentation of evidence of the test a compulsory aspect of a building’s sign-off process. There are 3 available methods for examining, recording and reporting the testing of extract fans. Using a vane anemometer, our testing procedure follows Method 3 – The minimum benchmark method.
The size, type and multifaceted parts of a building determine the level of air pressure testing it will receive. There are 3 levels and they are listed below. A single blower door fan is used for air tightness testing for single buildings and smaller non-dwellings not more than 4000m3. Level 2: Air pressure testing for simple and complex buildings larger than 4000 m³ gross envelope volume which does not include large and complex, high rise (LCHR) buildings, and phased handover/zonal buildings. The third level tests big and complex zonal and phased buildings and complex high rise buildings.
Air tightness testing determines the extent of air leaking out a building’s envelope. 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 air permeability rate for a dwelling can be found on the design-stage SAP report for that dwelling. Excess air leakage causes heat loss and discomfort due to the influx of cold air, also causing increased energy bill expense.
Air pressure testing involves the calculation of air escaping through the openings in a building. The result is written as m3/h/m2 – (m3 per hour) per square metre of building envelope. Air leakage testing is a requirement of Approved Document L2A. The maximum air permeability rate for a dwelling tested is 10m3/h/m2. The SAP or SBEM assessment for all buildings reduces the air permeability rate target. The design-stage SAP or SBEM assessment of a construction records its required air permeability rate. An excessive amount of air leakage leads to greater energy expenses, heat reduction, carbon dioxide discharge and draughts.
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. 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. With the right air permeability rate, the vents can operate at their best. We aim for the air permeability rate set by the vent manufacturers. Fans are placed in the smoke shaft to conduct an air tightness test. The openings for ventilation grilles and extract points on each floor are closed so that the state of the shaft itself is known. Once the test is completed and successful, the automatic opening vents are installed.
Buildings that are well insulated and air tight are the standard for buildings. As a result, a high-quality ventilation system that is adequate and performs as required is vital. Extract fans are tested by us. A building must have an optimal ventilation system to dispel humidity from bathrooms, kitchens and other rooms and extract odours and pollutants. We can also help you meet the Building Regulations targets. 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. The air tightness of a building improves its energy efficiency and internal environment.
External claddings and the internal building finishes might obscure a gap in the building fabric. This makes it hard to notice and can results to potential air leakage. If you know the leakage paths of a building, you will know if it is air tight.
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. Buildings that don’t undergo the test are penalised. All dwellings in a development should be tested to ensure optimum air tightness.
Send the drawings of your dwelling (plans and elevations) and its target air permeability requirements to our test engineers. 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. An air tight environment should be created in your building before the test to ensure optimal results. Do the following:
We undertake building envelope measurements before getting to the dwelling for the test. The building envelope is the surface area of the structural barrier of a building. It separates the interior from the exterior part of the dwelling The calculations, which are extracted from the drawings, are fed into our estimations when testing your building for air leaks.
It is defined as air leakage rate per hour per square metre of envelope area at the test reference pressure differential of 50 pascals (50n/m2). The envelope area, or measured part of the building, is 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.
Air change rates are often used as rules of thumb in ventilation design but they are seldom used as the actual basis of design or a calculation. To calculate ventilation rates for domestic buildings, the area and number of people living in the building are considered.
It is important to make sure the roof area and ground floor area of a building are equal. A cold roof has its insulation at the ceiling level, with space between the insulation and rafters.
A warm roof is a roof system where the insulation is fixed along the rafters with an air barrier inside the insulation. The envelope area is the boundary or barrier containing the overall internal ‘conditioned space’ separating it from the external environment (or non-conditioned spaces and adjacent buildings), and this is located on the warm side of the insulation.
Examine the wind speed, barometric pressure and temperature. Fix a fan to an aperture, usually the door, in the building. Ensure all the testing equipment is ready. Using the fan, measure the air flow volume, from the building fabric. Gradually increase the fan speed from 20-25 Pa to a maximum of 55-60Pa. Note the difference in air pressure in several parts of the building 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. Air Leakage Testing and 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: 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. 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. They also ensure that you spend less money. Here are the services we provide:
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 further makes it obligatory for new buildings to be tested for air permeability in line with existing building standards.
There are technical standards for air tightness test of buildings in the UK detailed by Air Tightness Test and Measurement Association (ATTMA). The technical standards ensure that all companies have similar testing procedures. They are:
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. Where there are only one or two new buildings, add an assumed value of 15m3/h/m2 to the DET/TER measurements; an air tightness test may not need to be carried out. 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 required on all residential developments (this may be a sample of units) and certain Non-Dwellings. If your building has added an estimated assessed rate of 15 m3/h/m2 in its calculations or its useful floor space is less than 500 m2, it may not have to take the test.
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.
Accredited testing companies issue air pressure reports. 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 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. We will state if your building has passed or failed the test and give advice on the actions you need to take if another test is needed.
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.
