Ventilation of habitable rooms through conservatories

A habitable room not containing openable windows may be ventilated through a conservatory (see Diagram 2.4) where – (a) there is, from the conservatory to outside, provisions for both – (i) rapid ventilation through one or more ventilation openings, with a total area given in Appendix B based on at least the combined floor area of the habitable room and conservatory; and (ii) background ventilation, a ventilation opening (or openings) of at least 8000 mm² equivalent area; and (b) there are openings (which must be closable) between the habitable room and the conservatory for – (i) rapid ventilation equivalent to paragraph 2.112(a)(i) above; and (ii) background ventilation equivalent to paragraph 2.112(a)(ii) above which should be typically located at least 1.7 m above floor level and need not be within the door frame.