April 10, 1989
BCAB #1055
Re: Ventilation in Crawl Space, Subsection 9.18.3.
With reference to your letter of February 23, 1989 regarding the ventilation of a crawl space. From the information submitted it seems that you have a crawl space which forms part of the heated enclosure.
An earlier Appeal #1009 dealt in some detail with this question, and as you refer to it in your letter we assume that you have a copy. to deal with one point in the letter, this decision is mandatory. In Appeal #1009 we stated that a crawl space forming part of the heated enclosure would be exempt from the provisions of Subsection 9.18.3. With this there was no alternative, if such a space is ventilated to the same extent as is required for occupied spaces, then there can be no objection.
We do, however, note a reference in one submission to ventilation only during the heating season. This is incorrect; if the crawl space is being included within the same enclosure as living space then Article 9.33.1.5. also applies. We consider this to mean that the mechanical ventilation system employed during the heating season must also provide adequate ventilation during the non-heating season, unless natural ventilation is provided for this period. From the information supplied by the authority having jurisdiction it appears that this is their purpose. If our understanding of the situation is correct, you seem to be in contravention of the Code.
J.C. Currie, Chairman