My plans for the extension contains the usual wording about ventilation and windows:
Windows to habitable rooms to have opening vents not less than 5% floor area of room, plus 8000mm2 controllable trickle ventilation. Kitchens and bathrooms to have 4000mm2 controllable trickle ventilation.
But I've been looking at the UPVC windows around and the trickle venting seems to be ugly sliding things on the inside, horizontal slots on the outside, and looks horrid. Also, it is a noise path even when "shut". What is the alternative to these, that will satisfy the regs ?
Simon.