Division B Part 7 governs new construction plumbing — covering drainage, waste, venting, water supply, and fixtures. It references CSA B149.1, the B64 backflow series, CSA B651 (accessible design), and ASME A112 fixture standards.

Three inspections: underground (before below-slab work is covered), rough-in (before walls are closed, after pressure testing), and final (after fixtures and trim are installed and water service is connected).

Ideally before construction documents are complete — their input on pipe routing and penetrations can prevent costly changes. At minimum, they should review drawings before permit submission and coordinate sleeve and penetration locations before concrete pours.

Installed after the slab is prepared but before concrete is poured. The contractor installs drains at required slopes (minimum 2%), places cleanouts, and positions sleeves for supply pipes. All underground work is inspected before concrete placement.

Plumbing is included in the overall Building Permit. The applicant submits mechanical engineering drawings to the building department, which reviews for OBC compliance. Inspections at each stage (underground, rough-in, final) are scheduled by the permit holder.

Insufficient vent sizing, improper drain slopes, missing cleanouts, improper trap-to-vent distances, fixtures installed without permits, and supply pipes not protected from freezing. Addressing these before inspection saves re-inspection costs.

Based on the fixture unit load of all connected fixtures plus backflow prevention demand. A mechanical engineer calculates peak demand and sizes the service. Municipal water pressure and available flow at the property line must be confirmed with the local utility.

As-built drawings, equipment warranties, backflow preventer initial certification reports, water heater commissioning records, TSSA certificates for boilers/pressure vessels, and fixture O&M manuals — all forming part of the building's Operations and Maintenance manual.