Understanding Trickle Vent Regulations
1. Can background ventilators be installed through a wall to meet the Part F requirements, instead of installing trickle ventilators in windows?
Ventilation can be provided through any appropriate means. Installing a background ventilator through a wall that provides the equivalent areas described in Approved Document F, volume 1 can be an acceptable route to compliance.
2. What do I need to do if I already have a wall ventilator in my room?
When replacing a window in a room where there is already a wall ventilator present which meets the minimum equivalent areas in Approved Document F, volume 1, no further background ventilation needs to be added after replacing the windows.
Where there is an open-flued appliance in the room, there should be permanently open air vents to supply the air for combustion. These air vents are there to meet Part J requirements. These air vents should not be considered as existing ventilation for Part F and therefore extra vents should be installed.
3. Is a window with night-vent capability a suitable solution for background ventilation when replacing windows?
Providing a night-vent (also referred to as a night-latch), where a window can be locked slightly ajar, is not an appropriate background ventilation solution. This is because windows locked on the night-latch do not provide a sufficiently secure means of background ventilation.
4. When replacing windows, can the Building Regulations requirements be met through a homeowner signing a disclaimer that they will install background ventilation at a future date or that they do not wish to have any installed?
For work to comply with the Building Regulations, all requirements must be met in full.
Members of competent person schemes self-certify that their work complies with the relevant requirements of the Building Regulations including Regulation 4(3). The work can only be certified by a member of a competent person scheme if the work complies with the Building Regulations, which includes the requirement that ventilation for the building has not been made less satisfactory as a result of the work.
A disclaimer signed by the homeowner stating that they do not wish to have background ventilators or that they will be installed in future is not a suitable way of complying with the Building Regulations. Work must comply with the Building Regulations and competent person schemes must monitor their registrants and take action against any registrant who is found to have carried out non-compliant work.
Purchasing an indemnity policy is also not a suitable alternative to meeting the requirements of the Building Regulations in full.
5. Will trickle ventilators allow noise and air pollution into homes?
Without good ventilation, there will be more substances in the air that can cause harm to people. This includes pollutants from cooking, cleaning products, hygiene products and fabric furnishings. Diluting pollutants generated inside the home using ventilation is necessary, but importantly, outdoor air quality affects indoor air quality. There is also a high risk of mould in homes which are poorly ventilated.
Approved Document F, volume 1 describes how ventilation systems should be designed to minimise the intake of external air pollutants, by locating ventilation intakes away from the direct impact of the sources of local pollution. Guidance on minimising the intake of external pollutants can be found in paragraphs 2.2 to 2.9 of Approved Document F, volume 1. Trickle ventilators can be located on the less polluted side of the building to reduce the ingress of outdoor air pollution.
We appreciate that noise may be an issue with façades facing noisy environments. We recommend that noise attenuating background ventilators are fitted in these circumstances, as outlined in paragraph 1.54 of Approved Document F, volume 1.