Building Regulations Part F sets out the minimum ventilation standards for buildings in England, covering everything from fresh air supply to mechanical extract systems. Whether you're a contractor fitting out a new commercial space, a facilities manager overseeing building compliance, or a building services engineer specifying ventilation systems, understanding Part F is essential to delivering work that passes building control.
Updated in June 2022 as part of the UK Government's Future Homes and Buildings Standard drive, the revised Approved Document F introduced stricter requirements around air quality, system commissioning, and energy efficiency.
What Is Building Regulations Part F?
Building Regulations Part F is the section of the Building Regulations 2010 that governs ventilation in buildings across England. Approved Document F (ADF) provides the technical guidance that supports Part F compliance, and its core requirement is simple: buildings must have adequate means of ventilation for the people who use them.
The document sets out how ventilation systems should perform in practice, covering airflow rates, noise levels, maintenance access, and protection against draughts and external pollutants.
Part F applies to a broad range of building types and situations, including new builds, extensions, material changes of use, and existing buildings where ventilation-related work is carried out.
It does not apply to certain exempt buildings such as those with occupiable rooms at very low temperatures (like cold stores), and there are size thresholds that exclude very small spaces under 50m² or very large spaces over 320m².
What Changed in the 2022 Update to Part F?
The June 2022 revision to Approved Document F was one of the most significant updates to UK ventilation regulations in years. The document was split into two separate volumes: Volume 1 covering dwellings, and Volume 2 covering buildings other than dwellings.
This split was a direct response to the growing complexity of ventilation requirements across different building types, and it brought non-domestic buildings into much sharper focus than before.
Key changes introduced in the 2022 update include:
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Increased whole-building ventilation rates for dwellings, requiring a minimum of 0.3 litres per second per metre squared of floor area
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Mandatory testing, commissioning, and documentation for all mechanical ventilation systems
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A requirement that any building work must leave ventilation no worse than it was before the works started
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Updated guidance recommending trickle vents in replacement windows unless an alternative ventilation strategy is already in place
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New commissioning checklists recording design and achieved flow rates for both boost and trickle settings
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Increased focus on the ventilation needs of existing buildings, not just new builds
What Are the Four Ventilation Systems Under Part F?
System 1: Background Ventilators and Intermittent Extract Fans
This is the most common system in older and less airtight buildings. It combines natural background ventilation through trickle vents or air bricks with intermittent mechanical extract fans in wet rooms such as kitchens and bathrooms.
Under the 2022 update, this approach is now only recommended for buildings with an air permeability greater than 5 m³/(h.m²), meaning it is less appropriate for modern, airtight new builds.
For contractors working on refurbishments or extensions to existing buildings, this system remains practical and cost-effective. eFans stocks a wide range of extractor fans and air valves suited to these applications, including ceiling and wall-mounted options in both metal and plastic finishes.
System 2: Passive Stack Ventilation (PSV)
Passive Stack Ventilation uses ducts running from wet rooms up through the building and out through the roof to create a natural flow of air driven by temperature differences and wind pressure. It requires no mechanical components and is particularly suited to buildings where quiet, low-maintenance ventilation is a priority.
PSV systems must still be designed and installed to meet the extract rates set out in Approved Document F.
System 3: Continuous Mechanical Extract Ventilation (MEV)
Continuous Mechanical Extract Ventilation operates as a centralised system that extracts air constantly at a low background rate from multiple wet rooms, with the ability to boost extraction when needed. MEV is well-suited to airtight new builds where background ventilators alone would not provide sufficient airflow.
The system draws air in through trickle vents and pushes it out through a central extract unit, making it energy-efficient compared to multiple individual intermittent fans running on demand.
System 4: Mechanical Ventilation with Heat Recovery (MVHR)
MVHR is a balanced whole-building ventilation system that simultaneously supplies fresh filtered air and extracts stale air, recovering up to 85% of the heat from the outgoing air to pre-warm the incoming supply. It is the most energy-efficient ventilation solution available, and it is increasingly the preferred choice for new build projects designed to meet Part L energy efficiency standards alongside Part F ventilation requirements.
MVHR systems are mandatory to test and commission under the 2022 Part F update, with full documentation of design and achieved flow rates required before handover.
eFans supplies MVHR units and heat recovery ventilation equipment suitable for both domestic and commercial projects, from single-room decentralised units through to whole-building centralised systems.
How Does Part F Apply to Non-Domestic Buildings?
Volume 2: Buildings Other Than Dwellings
Approved Document F Volume 2 covers non-domestic buildings including offices, retail spaces, schools, healthcare facilities, and commercial premises. For these building types, the ventilation standard requires a minimum of 10 litres of fresh air per person per second, or 1 litre per second per metre squared of floor area, whichever is greater.
The document also sets specific extract rates for areas like commercial kitchens, sanitary accommodation, and car parks.
Facilities managers and M&E contractors working in commercial buildings need to ensure that ventilation system design is fully documented, that systems are commissioned by a competent person, and that maintenance access is built into the installation.
Non-compliance can result in building control refusing to sign off the works, which creates costly delays on projects.
Mixed-Use Buildings
Mixed-use buildings that contain both residential and commercial elements require careful handling under Part F. Where a commercial space and a dwelling share the same thermal envelope and the residential portion forms a substantial part of the overall floor area, the building may be treated as a dwelling and fall under Volume 1.
In most commercial-led mixed-use developments, however, Volume 2 applies to the non-domestic portions, and contractors should clarify this with building control at the design stage.
What Ventilation Products Are Required for Part F Compliance?
Selecting the right products is central to achieving Part F compliance, and the choice will depend on building type, airtightness, use, and the ventilation strategy specified by the building designer. For most commercial and residential projects, the following product types form the backbone of a compliant ventilation installation:
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Intermittent extract fans for wet rooms in System 1 installations, where the building has sufficient natural background ventilation
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MEV units for whole-building continuous extract in airtight or high-performance new builds
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MVHR systems where energy recovery and balanced ventilation are required, particularly in new commercial and residential builds targeting high energy performance
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Air valves and diffusers for supply and extract terminals that meet the required flow rates and noise criteria set out in Approved Document F
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Background ventilators and trickle vents for natural ventilation in less airtight buildings
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Weather louvres and grilles for external intake and exhaust points
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Fire dampers in ductwork that passes through compartment walls, where required under Building Regulations Part B
eFans supplies all of these product types from leading manufacturers, with free UK next-day delivery available and in-house engineers on hand to assist with product selection and specification.
What Are the Commissioning and Testing Requirements Under Part F?
Testing and Commissioning Mechanical Ventilation
The 2022 update to Approved Document F introduced mandatory commissioning requirements for all mechanical ventilation systems, and this is one of the areas that catches contractors out most often. Any mechanical ventilation system installed in a new or existing building must be inspected, tested, and commissioned by a competent person to verify that it achieves the design flow rates.
Both the trickle and boost rates must be measured, recorded, and documented on a commissioning sheet, which is then submitted to building control as part of the sign-off process.
Handover Documentation
Beyond commissioning, Part F requires that building owners and occupiers receive clear guidance on how the ventilation system works, why it matters, and how to maintain it. This includes user instructions, maintenance schedules, and details of the design airflow rates. For contractors and facilities managers, keeping this documentation accurate and accessible is not just good practice. It is a regulatory requirement.
Frequently Asked Questions
Does Building Regulations Part F apply to commercial buildings?
Yes, Part F applies to both domestic and commercial buildings in England. Commercial and non-domestic buildings are covered by Approved Document F Volume 2, which sets out specific ventilation rates and system requirements for offices, retail units, schools, healthcare buildings, and other non-residential premises.
Any building work that affects ventilation in a commercial building must comply with Volume 2 and be reviewed by a building control body.
What is the minimum ventilation rate required under Part F for non-domestic buildings?
For non-domestic buildings, Approved Document F Volume 2 requires a minimum outdoor air supply rate of 10 litres per second per person, or 1 litre per second per metre squared of floor area, whichever is the greater. Additional extract rates apply to specific areas such as commercial kitchens, toilets, and car parks.
These rates must be achieved and documented during the commissioning process before building control sign-off.
Does Part F apply to existing buildings and refurbishment projects?
Yes, Part F applies to existing buildings whenever ventilation-related work is carried out, or when other building work affects the performance of the existing ventilation. The 2022 update introduced a specific requirement that building work must not leave the ventilation in a worse condition than it was before the works began.
Contractors undertaking extensions, fit-outs, or material changes of use must assess the existing ventilation strategy and ensure the completed works comply with Part F.
Who is responsible for ensuring Part F compliance on a project?
Responsibility for Part F compliance sits with the building owner and the principal contractor carrying out the work, with support from the ventilation system designer and the commissioning engineer. Building control, either through the local authority or an approved inspector, is responsible for checking and signing off compliance.
For mechanical ventilation systems, a competent commissioning engineer must test and document the system performance before the building control sign-off can be granted.
What is the difference between MEV and MVHR under Part F?
Continuous Mechanical Extract Ventilation (MEV) is a System 3 solution that extracts stale air continuously from wet rooms across a building but does not recover heat from the outgoing air.
Mechanical Ventilation with Heat Recovery (MVHR) is a System 4 solution that both supplies fresh air and extracts stale air simultaneously, recovering up to 85% of the heat from the exhaust stream to warm the incoming supply air.
MVHR is the more energy-efficient option and is increasingly specified in airtight new build projects where both Part F ventilation and Part L energy efficiency requirements need to be satisfied together.
Does Part F cover ventilation in loft conversions?
Yes, Part F covers loft conversions and roof spaces where habitable rooms are created. When an existing open loft is converted into a usable room, adequate ventilation must be provided to prevent condensation forming within the roof structure. This typically requires a continuous airflow path between the insulation and the roof covering, achieved through openings at the eaves and ridge, alongside any mechanical extract ventilation required for the habitable space itself.