Trickle vents and ventilation when replacing windows
Why trickle vents are fitted to replacement windows and what Approved Document F expects.
Why fit trickle vents?
Modern windows seal much better than old ones, which can leave rooms short of fresh air and lead to condensation. Trickle vents give controllable background ventilation.
What does Approved Document F say?
In England, when windows are replaced the ventilation should be no worse than before. Where the old windows had trickle vents, the new ones should too; where they did not, ventilation must still be no worse than before, which usually means fitting trickle vents sized to Approved Document F or agreeing another approach with building control.
How do I order them?
Mark the windows that need vents on your schedule. Vents are routed into the frame head before dispatch, so they do not have to be cut on site.
This guide is general information for trade customers. The person carrying out the work remains responsible for meeting the building regulations and any planning requirements for the specific job.