What are the regulations on ventilation?
The Building Regulations, Part F – SI 556 (2009)
F1 -- Means of Ventilation
Adequate means shall be provided for people in buildings. This shall be achieved by:
limiting the moisture content of the air within the building so it does not contribute to condensation and mould growth and
limiting the concentration of harmful pollutants in the air within the building.
F2 -- Condensation in Roofs
Adequate provision shall be made to prevent excessive condensation in a roof or roof void above an insulated ceiling.