Section 9.7. Windows and Skylights

9.7.1. General

9.7.1.1. Application

(1) Windows and skylights shall conform to the requirements of this Section.

9.7.1.2. Minimum Window Areas

(1) Except as required in Article 9.7.1.3. and Sentence (3), the minimum window glass area for rooms in buildings of residential occupancy or that are used for sleeping shall conform to Table 9.7.1.2.
(2) The unobstructed glass area of a door or skylight is considered equivalent to that of a window.
(3) Work areas in live/work units shall conform to Clause 3.7.2.1 .(2)(a).
(4) Where rooms with different requirements for window glass area are combined as described in Sentence 9.5.1.4.(1), the more restrictive requirement shall govern.

Table 9.7.1.2.
Glass Areas for Rooms of Residential Occupancy
Forming Part of Sentence 9.7.1.2.(1)

9.7.1.3. Bedroom Windows

9.7.1.3. Bedroom Windows (1) Except where a door on the same floor level as the bedroom provides direct access to the exterior, every floor level containing a bedroom in a suite shall be provided with at least 1 outside window that,
(a) is openable from the inside without the use of tools,
(b) provides an individual, unobstructed open portion having a minimum area of 0.35 m2 (3.8 ft2) with no dimension less than 380 mm (15 in), and
(c) maintains the required opening described in Clause (b) without the need for additional support. (See Appendix A.)
(2) Except for basement areas, the window described in Sentence (1) shall have a maximum sill height of 1,000 mm (3 ft 3 in) above the floor. (See Appendix A.)
(3) When sliding windows are used, the minimum dimension described in Sentence (I) shall apply to the openable portion of the window.
(4) Where the sleeping area within a live/work unit is on a mezzanine with no obstructions more than I 070 mm (3 ft 6 in) above the floor, the window required in Sentence (I) may be provided on the main level of the live/work unit provided the mezzanine is not more than 25% of the area of the live/work unit or 20 m2 (215 ft2) whichever is less and an unobstructed direct path of travel is provided from the mezzanine to this window.

9.7.1.4. Window Opening into a Window-Well

(1) Where a window required in Article 9.7.1.3. opens into a window-well, a clearance of not less than 550 mm (21% in) shall be provided in front of the window.
(2) Where the sash of a window referred to in Sentence (1) swings towards the window-well, the operation of the sash shall not reduce the clearance in a manner that would restrict escape in an emergency.
(3) Where a protective enclosure is installed over the window-well referred to in Sentence (1), such enclosure shall be openable from the inside without the use of keys, tools or special knowledge of the opening mechanism.

9.7.1.5. Termites

(1) In localities where termites are known to occur and where windows or other openings at or below grade contain wood elements, the bottom of window wells or adjacent ground shall be at least 150 mm (57/s in) below the nearest wood unless the wood is pressure-treated with a chemical toxic to termites in accordance with Article 9.3.2.9.

9.7.1.6. Height off Window Sills above Floors or Ground (See Appendix A.)

(1) Except as provided in Sentence (2), openable windows in buildings of residential occupancy shall be protected by,
(a) a guard in accordance with Subsection 9.8.8., or
(b) a mechanism capable of controlling the free swinging or sliding of the openable part of the window so as to limit any clear unobstructed opening to not more than 100 mm (4 in) measured either vertically or horizontally where the other dimension is greater than 380 mm (15 in).
(2) Windows need not be protected in accordance with Sentence (1) where,
(a) the window serves a dwelling unit that is not located above another suite,
(b) the only opening greater than 100 mm (4 in) by 380 mm (15 in) is a horizontal opening at the top of the window,
(c) the top surface of the window sill is located more than 480 mm (1 ft 7 in) above the finished floor on one side of the window, or
(d) the window is located in a room or space with the finished floor described in Clause (c) located less than 1 800 mm (5 ft 11 in) above the floor or ground on the other side of the window.

9.7.1.7. Air Infiltration of Exterior Windows

(1) Air infiltration of exterior windows shall not exceed 0.775 L/s (1.64 cfm) for each metre of sash crack when tested at a pressure differential of 75 Pa (0.011 psi) in conformance with ASTM E283, "Determining the Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen".