Part F building regulations cover ventilation requirements for new build properties in the United Kingdom. We cover a range of the most frequently asked questions on this topic below.

What Is Part F Ventilation Testing?

Part F of the Building Regulations 2010 guides building ventilation, air quality, and condensation prevention. Ventilation replaces indoor air with fresh outside air.

In domestic properties, ventilation must circulate throughout the entire building. Extract ventilation is required in humid or polluted areas, like over an oven. Purge ventilation allows intermittent rapid ventilation in habitable rooms, often through windows or external doors.

Non-domestic properties prioritise continuous circulation of clean air. This is achieved through easily accessible and maintainable air conditioning systems that minimize the risk of airborne illnesses.

Do I need Part F Ventilation?

Part F requires adequate ventilation for building occupants. Fixed mechanical ventilation systems must be commissioned and tested to ensure compliance.

Requirements do not apply to buildings or spaces that people do not normally enter, solely used for storage, or garages connected to a single dwelling.

Why is Part F Ventilation Important?

Ventilation supplies fresh air for breathing, dilutes pollutants and odors, controls excess humidity, and aids thermal comfort. Building Regulations do not control thermal comfort (Part L addresses energy use due to solar gains).

Improperly ventilated buildings with no system to remove excess water vapor may experience condensation, dampness, and mold growth. A survey found that 58% of homes have condensation issues.

Poor indoor air quality and pollution contribute to health issues, premature mortality, and NHS costs. Ventilation improves air quality, reduces airborne viruses’ impact, and enhances personal health and well-being.

Reducing airborne virus transmission is crucial amid COVID-19. The virus spreads through exhaled droplets and particles, remaining suspended indoors. Fresh air and regular ventilation can reduce infection risk by over 70%.

What is the relationship between Part L and Part F?

Part L addresses uncontrolled infiltration, while Part F focuses on purpose-provided ventilation. Minimising infiltration and supplying sufficient purpose-provided ventilation are important.

Air tightness measures in Part L limit infiltration. Approved document F suggests methods for achieving purpose-provided ventilation with reasonable airtightness.

The English guidance sets a threshold of 5 m3h-1m-2 for air tightness. Lower air permeability requires more purposeful ventilation, influencing the choice between mechanical or natural ventilation. Airtightness affects the necessary ventilation rate.

Types of Ventilation

Extract ventilation removes water vapor and pollutants from specific rooms.

Whole building ventilation dilutes residual pollutants and removes water vapor throughout the building.

Purge ventilation aids in removing high concentrations of pollutants and is intermittent.

Ventilation can be delivered naturally, mechanically, or through a hybrid system. Naturally ventilated buildings use a combination of ventilators. Dwellings commonly use intermittent extract fans, trickle ventilators, and windows. Mechanically ventilated buildings use the same ventilators for local extract, whole-building ventilation, and sometimes purge ventilation.

What next?

As air tightness in buildings improves, so too must the ventilation, in order to prevent the build-up of black mould. We often carry out ventilation testing at the same time as air tightness tests to keep costs as low as possible for housebuilders. Get in touch to book your test today.

Keep Informed

Sign Up Now For Exclusive Energy Insights!

"*" indicates required fields

This field is for validation purposes and should be left unchanged.