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Building Regulations Part F: Ventilation versus the Real World

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As with most other aspects of residential and business premises regulations, ventilation has a number of important documents that refer in depth to various applications of building and environmental concerns. The Building Regulations Approved Document F 2010 is one such set of rules and it applies to ventilation requirements for buildings in England and Wales. It can be downloaded from 

The document considers ventilation issues such as purpose-provided ventilation as well as infiltration factors. As with many other official regulations, constant reviews take place and changes are made, so if you want to make sure that you are compliant with current building standards, it is worth checking the Planning Portal website for any updates.


What is Approved Document F?

Approved Document F offers guidance for anyone who wants to know which building regulations specifically apply to the area of ventilation. Of course, this is important because ventilation is often overlooked in comparison with other elements such as insulation, but the question also arises as to whether the regulations are achievable in terms of real world applications in the most common typical cases. 

As is often the case with any approved document, the details can be interpreted in different ways, although Document F does clearly state that adequate ventilation must be provided to prevent excess condensation build-up if it might be bad enough to present a potential cause of damage to the actual structure of a property. This is a fairly unequivocal position which essentially ensures that air must be allowed to flow through the property, thereby maintaining an acceptable level of air quality indoors. 

Making certain that your house has adequate ventilation solutions in place is absolutely vital as the damage caused by damp and mould can lead to numerous issues which may be difficult or even impossible to reverse. These include mould on the walls and furniture, structural damage to your house or even long-term health issues. Installing an effective ventilation system can eliminate these problems while supporting the health of both you and your household. This is why you need to ensure that your ventilation provider is totally familiar with Approved Document F. Here at EnviroVent, we are national experts in our field and can guarantee that your property will have the ventilation system it needs.


Limitations of Approved Document F

A new build property must comply with building regulations in areas such as installation, inspection and testing when it comes to ventilation apparatus. Providing accurate information when installing fixed ventilation systems also applies to any such work undertaken in existing properties too. The complexity of the issues involved means that it is essential to consider the various ventilation strategies and system designs that might be involved at the earliest stages of design planning.

In Approved Document F, there are a number of different systems for ventilation that come under consideration. Each of these is ranked by performance rates and the document sets out the minimum requirements that must be put in place to make sure that the air quality indoors is adequate and the health risks to occupants are not compromised.

Infiltration is one issue as the uncontrollable air exchange between outdoors and the inside of a building can obvious negate any positive ventilation system benefits. Purpose-provided ventilation is basically the term that covers any form of controlled air exchange between the two different environments and as such is an umbrella phrase which covers many different approaches, strategies and systems


Background Ventilation

Whether for a new build or an existing property, a ventilation solution must cover the basic requirements set out in Document F in the same ways. This is why one of the most common approaches to complying with the regulations is to use intermittent extractor fans with background vents. These vents can take the form of trickle vents in UVPC windows while the fans themselves can often be located in bathrooms, kitchens and utility rooms. Whatever the settings that are actually chosen, the important thing is to make sure that ventilation airflow rates meet the minimum intermittent extract rates as set out in the document.

For continuous systems calculating the whole building ventilation rate and whole building extract ventilation rate from the tables included in the document allows a comparison between the boost rate, or continuous (trickle) rate. The former should always be higher than the latter.


Ventilation With Heat Recovery

Mechanical Ventilation with Heat Recovery (MVHR) is also covered under Approved Document F in System 4. This system is a way of providing filtered fresh air in an energy efficient way to ensure that an indoor controlled climate is created which is comfortable all year round. As part of the process, the stale moist air from wet rooms is extracted and expelled from the building. Kitchens and bathrooms obviously benefit from this approach, as can utility and en-suite spaces. 


Alternative Systems

As well as the more established ventilation systems, Building Regulations Approved Document F looks at others which require European certification by a Technical Approval body. These different solutions must also comply with the requirements stated in F1 Approved Document F section 4.17.

The document says: “Other ventilation systems and devices, perhaps following a different strategy (e.g. Positive Input Ventilation) may provide acceptable solutions, provided it can be demonstrated to the Building Control Body (e.g. by a BBA Certificate) that they meet Requirement F1.”

New concepts such as sophisticated whole-house ventilation systems are covered by this part of the document. One of the ways in which these work is by first diluting, then displacing and replacing high humidity levels which then in turn controls the condensation which leads to mould growth.

In these systems, trickle vents may not needed The requirements of the BBA certificate and ADF need to be in compliance. This can usually be achieved by placing continuous extract fans in various positions if there is a remote wet zone which is located away from a central hallway. 


Positive Input Ventilation

Positive Input Ventilation is a more cost effective solution than heat recovery ventilation and can be utilised all year round. This type of system ranks highly in terms of energy efficiency as it takes advantage of the benefit of solar gain by including the loft space in the way that heat distribution is managed and provided.

Up to 10% of annual heating costs can be saved in this way, and as an added bonus, dust mite problems are also reduced and this can be a major advantage for anyone who suffers with asthma or allergy-based conditions. The indoor air quality is changed from being humid and unpleasant to become a fresh and healthy living environment which is free from condensation. 


Real World Solutions

As Document F shows, there are many different ventilation systems that might be suitable for a range of properties and each has to be chosen on its own merits and then checked to ensure it complies with existing regulations. These systems include background ventilation devices, such as extractor fans; energy efficient solutions such as MVHR, Continuous extract and Positive Input Ventilation.. To find out which of the available options will be best for you, a ventilation specialist should be included in the planning team in order to assess your property and then make recommendations.

Stale air and bad odours can be more than just health hazards, they can easily make an indoor environment simply unpleasant. In a home this can affect the quality of life for everyone who lives there, so knowing which ventilation system will offer the best solution and then having it professionally installed can bring peace of mind as well as having day to day positive effects. 

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