FAQ Trickle Vents

No, a disclaimer is not an acceptable solution. Building Regulations are set out in law and cannot be circumvented by disclaimers.

It’s the room type that sets out the size of background ventilation required. A habitable room such as a lounge, for example, requires in most instances 8000mm² (Equivalent Area). This could be made up of 4 x 2000mm² or 2 x 4000mm² or any other combination.

The installer is the competent person and should be designing the window to achieve building regulation compliance where feasible. 

Alternative ventilation types can be utilised if they can satisfy a BCB (building Control Body) that they are suitable. With “Air Bricks” these would need to provide the correct amount of ventilation and be controllable. Cavity or under floor vents are not background ventilation. 

If continuous mechanical ventilation is installed then those rooms do not require vents but all habitable rooms will require 4000mm² vents to be installed

Yes. Two stage locking handles or night vents are not acceptable, as they are less secure and the equivalent area cannot be accurately measured. 

It is up to the competent installer to adhere to the Building Regulations.

Approved Document F1 is only applicable to dwellings. Approved Document F2 covers all buildings other than dwellings. This does require background ventilation to be installed when replacing windows, but with different size and location requirements.

Background ventilation is assessed per room, not per window or door. There may be instances where background vents should be installed in doors. For example, a room that is only opening to the outside, is a door such as a set of French doors in a lounge. Hallways on the other hand, are not habitable rooms and therefore a door in hall would not require background ventilation. 

If you cannot install the required amount of ventilation in a window, then you should install whatever is feasible. 

This would be a possible solution. A larger frame section may be another possibility or an over glass ventilator. 

No, background ventilators must be controllable so could be closed at times of high pollen etc. to mitigate the issue. 

Listed buildings and sometimes conservation areas are exempt.

If sound is an issue then a noise attenuating background ventilator should be fitted.

Building Regulations require that the ventilation in your home is not made worse by installing energy efficiency measures. When work is done to homes, gaps and cracks are often sealed up. These gaps and cracks were providing ventilation and in older homes may have been the only source of ventilation. 

Refer homeowners to

Click Here: Existing Home Ventilation Guide