67. Windows separating heated space from unheated space or the outside air shall be designed to limit air infiltration to a maximum of 0.77 L/s per metre of sash crack when tested at a pressure differential of 75 Pa in conformity with ASTM E283-84 Standard Test Method for Rate of Air Leakage Through Exterior Windows, Curtain Walls and Doors.
O.C. 89-83, s. 67; O.C. 1211-92, s. 9.