Hi!

We are studying the possibility to certificate a 20 stories residential building with 6 apartments per floor. Four of the apartments may have a bedroom ventilated only by a window that leads to an air shaft (lightwell). The window does not have an exterior view.

We would like to know if the ventilation area provided by the opening is bigger than 8% of the occupiable floor area of the bedroom, the ventilation requirements are complied.

Thank you in advance!