Photo Source: Summerhill

3.1.1.8.(1) Except as provided in Sentence (2), the thermal resistance values for insulation required by Articles 3.1.1.2., 3.1.1.3. and 3.1.1.11. for exposed ceilings with attic spaces are permitted to be reduced

(a) directly above access hatches, and

(b) near eaves to the extent made necessary by the roof slope and required ventilation clearances,

Except that the thermal insulation value at the location directly above access hatches and inner surfaces of exterior walls shall be not less than RSI 3.52 (R-20).

(2) Where 250 mm (10") high heel is required near the eaves, the available space on the inner surface of the wall below the roof venting space shall be fully insulated.