Ventilation for Homes & Non-Dwellings - Building Regulations Doc F

Ventilation is the "hidden hero" of building safety.
This video explores the 2021 edition of Approved Document F, which dictates how buildings in England must "breathe".
Moving away from uncontrolled drafts, the regulations now demand purposeful, controlled ventilation to protect occupants from invisible threats like moisture, cooking pollutants, and cleaning products.

Volume 1: Dwellings (Our Homes) For residential spaces, the document outlines a three-part respiratory cycle:
• Extract Ventilation: The "targeted exhale" of moist air from kitchens and bathrooms. Notably, a kitchen requires an extract rate of 30 L/s with a cooker hood, but this doubles to 60 L/s without one.
• Whole Dwelling Ventilation: A constant "gentle inhale" of fresh air.
• Purge Ventilation: A "powerful cough" (like opening windows) to quickly clear air after painting or burning food. A critical, often-overlooked detail for home ventilation is the mandatory 10 mm gap under internal doors, which acts like the building’s "bronchial tubes" to allow air to circulate to extract fans.

Volume 2: Non-Dwellings (Offices, Gyms, and Commercial Spaces) Commercial spaces face more complex needs. In an office, the standard is 10 liters of fresh outdoor air per second per person. Following recent public health insights, there is a new focus on infection control; systems must now be able to switch to 100% outdoor air or utilize UVC light or HEPA filters to clean recirculated air.
Performance and Compliance
• CO2 Monitoring: In many public spaces, mains-powered CO2 monitors are now mandatory. These serve as a "traffic light" for air quality: levels under 800 ppm indicate a well-ventilated space, while readings over 1500 ppm are a red flag for poor ventilation.
• Testing (Regulation 44): Compliance is not optional. All mechanical systems must be physically tested to prove airflow rates match the design, with results submitted to Building Control.
• Home User Guide: New homeowners must receive a guide explaining how to operate their system and why they should never block trickle vents.
Proper ventilation is no longer about "ticking a box"—it is a non-negotiable requirement for creating healthy, resilient buildings.

Analogy for Understanding:
Think of Approved Document F as a manual for a building's lungs. Just as a person needs a steady intake of oxygen and a way to exhale carbon dioxide to stay healthy, a building needs Extract Ventilation to "exhale" moisture and pollutants, Whole Dwelling Ventilation to "inhale" fresh air constantly, and Purge Ventilation for those moments it needs to "cough" out a sudden burst of bad air. Without this controlled cycle, the building effectively "suffocates," leading to damp, mold, and poor health for its inhabitants.

--------------------------------------------------------------------------------
Visit and subscribe to the Building Regulations Copilot YouTube channel for more technical deep dives. For specific project queries, visit us at buildingregulationscopilot.com.

--------------------------------------------------------------------------------
For more videos like this please visit the Building Regulations Copilot YouTube channel @BuildingRegulationsCopilot
Visit https://buildingregulationscopilot.com for 24/7 responses to multi-country building regulations related queries.