Ventilation
Trickle vents and background ventilation under Part F: Equivalent Area explained, how much each room type needs, and the order-stage trap that catches homeowners before the windows are even made.
Background ventilation is set by Approved Document F, and the decisions get locked in the moment you order your windows. Get the Equivalent Area wrong and the fix can mean new window frames. The trickle vents guide explains what Equivalent Area means, how much each room type needs, how to get the figures confirmed in writing on the window quotation, and the acoustic and humidity-activated options for noisy or draughty spots. Read it before you sign off a window order.
Where this fits in the build
Trickle vents belong on the order you place during windows and doors, weeks before the frames are made, and building control checks that they are present and working. Background ventilation works alongside the kitchen extract, which is planned separately at extractor and ventilation. The cooker hood guide covers the extraction side.
