R303.2

Section R303.2 is titled 'Adjoining rooms' and covers the requirement for the allowance of light and ventilation sharing with rooms that do not have direct openings to the exterior. Dimensions for unobstructed areas which allow light and ventilation to reach adjoining rooms is established. The purpose of this section is to assure interior rooms get adequate light and ventilation for health and comfort of the occupants. This section has an exception which allows for alternative measurements where the adjoining room borders a thermally isolated sun room or patio cover. The purpose of this exception is to allow for sunrooms and patio covers which may otherwise be prohibited by the base language.

The model shows 2 partial dwelling sections with overlays that pop up to show each of the required dimensions. The 1st shows an adjoining room with 3 overlays: The common wall total area with the hatched portion showing that half the area is open; the floor area of the adjoining room with a hatched overlay of the open area which must be at least 10% of that floor area; and, a hatched overlay of the open area which must be 25 sq.ft. or greater. The 2nd shows an adjoining room next to a patio cover with 2 overlays: the floor area of the adjoining room with the hatched overlay of the openable areas which must total at least 10% of that floor area; and, a hatched overlay of the openable areas which must total at least 20 sq.ft.