Vents on new roofs

moneyistooshorttomention

That being:

a. Does there have to be from a user pov?

b. Is there a legal requirement (of the mandatory variety) that dictates there must be?

Doozergirl

You use breathable membrane now, not vents.

Furts

Yes you need roof ventilation. It is mandatory and is covered by the Buildings Regulations. How this is achieved comes down to design, roof pitch and roof type. It also comes down to what purpose your roof is meant to achieve - dead space, storage, or a living room - plus where your insulation is located - at ceiling level, or following the rafters.

Consider strip ventilators along soffits (good and neat) to twist and lock vents (beware here), to over fascia ventilation (be careful with the felt detail, but good on insulation principles), and ridge ventilation (whilst it may not be mandatory always worth considering). To this it is vital you consider cold bridging, and do not allow any insulation to obstruct the air flow.

All this, and more, should receive careful thought. If you get it wrong the consequences can be serious from damp. rot and condensation viewpoints.