Ventilation: Approved Document F, Volume 1 — Dwellings

F1(1) O N L I N E V E R S I O N 1.22 Minimum extract ventilation rates for continuous extract systems are specified in Table 1.2. A continuous rate is given for the general operation of the fan and a high rate for when additional extraction is required. Table 1.2 Minimum extract ventilation rates for continuous extract systems(1) Room High rate (l/s) Continuous rate Kitchen 13 The sum of all extract ventilation in the dwelling on its continuous rate should be at least the whole Utility room 8 dwelling ventilation rate given in Table 1.3 Bathroom 8 Sanitary accommodation 6 NOTE: 1. If the continuous rate of ventilation provided in a room is equal to or higher than the minimum high rate specified in the table, no extra ventilation is needed. Whole dwelling ventilation 1.23 Supply air for the dwelling should be delivered through one of the following means. a. Continuous supply fans. b. Background ventilators. 1.24 The minimum whole dwelling ventilation rate for the supply of air to the habitable rooms in a dwelling should meet both of the following conditions. a. A minimum rate of 0.3 litres per second per m2 of internal floor area (this includes all floors, e.g. for a two-storey building, add the ground-floor and first-floor areas). b. A minimum rate determined by the number of bedrooms, as specified in Table 1.3. Table 1.3 Minimum whole dwelling ventilation rates determined by the number of bedrooms Number of bedrooms(1)(2) Minimum ventilation rate by number of bedrooms (l/s) 1 19 2 25 3 31 4 37 5 43 NOTES: 1. If the dwelling only has one habitable room, a minimum ventilation rate of 13l/s should be used. 2. For each additional bedroom, add 6l/s to the values in Table 1.3. 1.25 Internal doors should allow air to flow through the dwelling by providing a minimum free area equivalent to a 10mm undercut in a 760mm wide door. Doors should be undercut to achieve one of the following. a. If the floor finish is fitted: 10mm above the floor finish. b. If the floor finish is not fitted: 20mm above the floor surface. 10 Approved Document F Volume 1, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N