Mansard or Gambrel Roof Ventilation,

(1)  The lower portion of a mansard or gambrel style roof need not be ventilated.

    (2)  The upper portion of roofs described in Sentence (1) shall be ventilated in conformance with the requirements in Articles 9.19.1.1. to 9.19.1.3.

Article 9.19.1.4 Ontario Regulation 332/12 Building Code,   Information published by oncodes.ca for educational purposes only.