12.3.3.

(1) This Subsection applies to the thermal design of buildings to which Clause 12.2.1.1.(3)(b)v1v2 applies.

(1) The materials for, and the installation of, thermal insulation and vapour barrier protection shall conform to Section 9.25.

(2) Foamed plastic thermal insulation shall be protected as described in Article 9.10.17.10.v1

(3) Crawl spaces shall conform to Section 9.18.

(4) Roof spaces shall conform to Section 9.19.

(5) Ventilation requirements shall conform to Section 9.32.

(6) Heating and air-conditioning requirements shall conform to Section 9.33.

(1) Except as provided in Articles 12.3.3.4. to 12.3.3.8., and except for doors, windows, skylights and other closures, the thermal resistance of each building assembly through any portion that does not include framing or furring shall conform to Table 12.3.3.3.

(1) Except as provided in Article 12.3.3.5., the thermal resistance of the insulated portion of a building assembly that incorporates metal framing elements, such as steel studs and steel joists, that act as thermal bridges to facilitate heat flow through the assembly, shall be 20 per cent greater than the values shown in Table 12.3.3.3., unless it can be shown that the heat flow is not greater than the heat flow through a wood frame assembly of the same thickness.

(1) Article 12.3.3.4. does not apply for building assemblies incorporating thermal bridges where the thermal bridges are insulated to restrict heat flow through the thermal bridges by a material providing a thermal resistance at least equal to 25 per cent of the thermal resistance required for the insulated portion of the assembly in Article 12.3.3.3.

(1) The thermal resistance of a building assembly may be reduced by not more than 20 per cent from that required in Articles 12.3.3.3. and 12.3.3.4., and the amount of glazing may be increased to more than permitted in Sentence 12.3.3.11.(2), where it can be shown that the total calculated heat loss from the building enclosure does not exceed the heat loss that would result if the enclosure were constructed in conformance with the minimum thermal resistance requirements in Articles 12.3.3.3. and 12.3.3.4. and with the maximum amount of glazing permitted in Sentence 12.3.3.11.(2), provided no allowance is made for solar heat gains or for the orientation of the glazing as described in Sentence 12.3.3.11.(4).

(1) The thermal resistance values in Articles 12.3.3.3. and 12.3.3.4. for roof or ceiling assemblies that separate heated space from unheated space or the exterior may be reduced near the eaves to the extent made necessary by the roof slope and required ventilation clearances, except that the thermal resistance at the location directly above the inner surface of the exterior wall shall be at least 2.1 m²∙°C/W.

(1) The thermal resistance values required in Article 12.3.3.3. may be reduced to take into account the effect of thermal inertia resulting from the mass of the building in conformance with DBR Building Research Note No. 126, “Relation Between Thermal Resistance and Heat Storage in Building Enclosures”.

(1) Sentence (2) applies to construction for which a permit has been applied for before January 1, 2009.

(2) Foundation walls enclosing heated space shall be insulated from the underside of the subfloor to not less than 600 mm below the adjacent exterior ground level.

(3) Sentence (4) applies to construction for which a permit has been applied for after December 31, 2008.

(4) Foundation walls enclosing heated space shall be insulated from the underside of the subfloor to not more than 380 mm above the finished floor level of the basement.

(5) Insulation applied to the exterior of a slab-on-ground floor shall extend down at least 600 mm below the adjacent exterior ground level or shall extend down and outward from the floor or wall for a total distance of at least 600 mm measured from the adjacent finished ground level.

(1) Where an enclosed unheated space, such as a sun porch, enclosed verandah or vestibule, is separated from a heated space by glazing, the unheated enclosure may be considered to provide thermal resistance of 0.16 m²∙°C/W, or the equivalent of one layer of glazing.

(1) Except as provided in Sentences (2) and (3), windows and all glazing that separates heated space from unheated space or the exterior shall conform to Articles 12.3.2.6. and 12.3.2.8.

(2) Except as provided in Sentences (3) and (4), the total area of glazing, including glazing for doors and skylights, that separates heated space from unheated space or the exterior shall not exceed 20 per cent of the floor area of the storey served by the glazed areas and shall not exceed 40 per cent of the total area of the walls of that storey that separates heated space from unheated space or the exterior. (In the case of a sloping wall, the area of the opaque portion of the wall is calculated as its projected area on a vertical plane.)

(3) Where the thermal resistance of glazing is different from that required in Sentence (1) and Article 12.3.3.10., the area of such glazing for the purpose of applying Sentence (2) may be assumed as being equal to the actual area multiplied by the ratio of the required thermal resistance divided by the actual thermal resistance of the glazing.

(4) Except as provided in Sentence (5), the area of glazing that contains clear glass or that has a shading coefficient of more than 0.70 that is unshaded in the winter and faces a direction within 45° of due South may be assumed to be 50 per cent of its unshaded area in calculating the maximum area of glazing in Sentences (2) and (3) provided the building is designed with a system that is capable of distributing the solar heat gain from such glazed areas throughout the building. For the purpose of determining whether or not the glazing is shaded in the winter, the shading shall be calculated using the noon sun angles of December 21.

(5) Sentence (4) shall not apply where the building is designed to be cooled unless the glazing described in Sentence (4) is shaded in the summer with exterior devices. For the purpose of determining whether or not the glazing is shaded in the summer, the shading shall be calculated using the noon sun angles of June 21.

(1) Air curtains shall not be used in place of exterior doors.

(2) Except for doors used primarily to facilitate the movement of vehicles or handling of material, infiltration around doors shall conform to the appropriate requirements in Article 12.3.3.13.

(3) Except for doors on enclosed unheated vestibules, all doors that separate heated space from the outside shall conform to Articles 12.3.2.7. and 12.3.2.8.

(1) Windows that separate heated space from unheated space or the exterior shall be designed to limit the rate of air infiltration to not more than 0.775 L/s for each metre of sash crack when tested at pressure differential of 75 Pa 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”.

(2) Manually operated exterior sliding glass door assemblies that separate heated space from unheated space or the exterior shall be designed to limit air infiltration to not more than 2.5 L/s for each square metre of door area when tested in conformance with Sentence (1).

(3) Except where the door is weather-stripped on all edges and protected with a storm door or by an enclosed unheated space, exterior swing type door assemblies for dwelling units, individually rented hotel rooms and suites shall be designed to limit the rate of air infiltration to not more than 6.35 L/s for each square metre of door area when tested in conformance with Sentence (1).

(4) Door assemblies other than those described in Sentences (2) and (3), that separate heated space from unheated space or the exterior shall be designed to limit the rate of air infiltration to not more than 17.0 L/s for each metre of door crack when tested in conformance with Sentence (1).

(5) Caulking material to reduce air infiltration shall conform to the requirements in Subsection 9.27.4.

(6) The junction between the sill plate and the foundation, joints between exterior wall panels and any other location where there is a possibility of air leakage into heated spaces in a building through the exterior walls, such as at utility service entrances, shall be caulked, gasketed or sealed to restrict such air leakage.

(7) Air leakage between heated space and adjacent roof or attic space caused by the penetration of services shall be restricted in conformance with the requirements of Subsection 9.25.3.v1