Approved Document F - UK Ventilation Standard
Approved Document F establishes UK Building Regulations requirements for ventilation in dwellings and non-domestic buildings. It ensures adequate indoor air quality, condensation control, and pollutant removal through natural or mechanical ventilation systems.
Overview
Approved Document F is part of the UK Building Regulations and provides practical guidance on meeting ventilation requirements for residential and non-domestic buildings. The document aims to ensure adequate indoor air quality (IAQ) for occupant health, control moisture to prevent condensation and mold growth, and dilute and remove indoor air pollutants. Document F specifies minimum ventilation rates, system design requirements, and performance standards for different building types and uses. It covers purge ventilation (for rapid air change), background ventilation (continuous trickle ventilation), and extract ventilation (for wet rooms like kitchens and bathrooms). The document addresses both dwellings (F1) and buildings other than dwellings (F2). Updated versions emphasize energy-efficient ventilation strategies including mechanical ventilation with heat recovery (MVHR) and demand-controlled ventilation. Document F works in conjunction with Approved Document L (energy efficiency) to balance ventilation requirements with heat loss.
Key Features
- Minimum ventilation rates for different room types and occupancies
- Requirements for purge, background, and extract ventilation
- Mechanical ventilation with heat recovery (MVHR) system specifications
- Intermittent extract fan performance standards for kitchens and bathrooms
- Continuous mechanical extract ventilation (MEV) system design
- Natural ventilation design guidance including stack effect and cross-ventilation
- Air permeability testing and building envelope airtightness standards
- Provision for future installation of ventilation equipment
Applicability
Approved Document F is primarily used by:
- Ventilation designers and M&E consultants for system specification
- HVAC contractors installing mechanical ventilation systems
- Architects for natural ventilation design and window sizing
- Building control officers for plan approval and commissioning verification
- Energy assessors for SAP calculations and energy performance certificates
- Building services engineers for commercial ventilation design
- Passivhaus designers integrating high-performance ventilation
Geographic Application: Applies to England. Scotland, Wales, and Northern Ireland have separate but generally similar ventilation requirements within their respective building standards systems.
Comparison Notes
- More prescriptive than US codes - Specific ventilation rates and system types required; less flexibility than ASHRAE 62.1/62.2
- Heat recovery emphasis - Strong focus on MVHR for energy efficiency, reflecting UK climate and energy costs
- Coordinates with Part L - Balances ventilation with thermal efficiency more explicitly than US codes
- Airtightness requirements - Mandates air permeability testing in new dwellings; less common in US residential
- Background ventilation - Trickle ventilators in windows standard practice in UK; rare in US
Official Source: https://www.gov.uk/government/publications/ventilation-approved-document-f