In accordance with the state building code, the plumbing and mechanical systems are inspected prior to covering or concealing any portion of the system. The inspection takes place after the installation of all water piping, drain, waste vent piping, fuel gas piping, HVAC ducting, range, dryer and bath exhaust ducting, furnace, boiler, water heater, unit heaters, and/or other fuel fired appliances and their venting system. (IAQ/whole house fans as applicable.) Also in accordance with the state building code, water or air pressure testing is required on all water, drain, waste and vent piping.