What NB building code requirements apply to a garage-to-bedroom conversion in Miramichi?

Converting a garage to a bedroom in Miramichi triggers a change of occupancy under the NB Building Code, which means the space must meet all residential habitable-room standards — including minimum ceiling height, egress windows, fire separation, insulation, electrical, heating, and ventilation requirements. A building permit from the City of Miramichi is mandatory, and the work will be inspected at multiple stages to confirm code compliance.

Ceiling height is one of the first requirements to verify. The NB Building Code requires a minimum clear ceiling height of 2.3 metres (approximately 7 feet 6 inches) in habitable rooms, including bedrooms. Most standard garages have 8-foot (2.44-metre) stud walls, which leaves just enough room after adding insulation and drywall to the ceiling — but it is tight. If your garage has lower walls or if the ceiling structure reduces the clear height below 2.3 metres, you may need structural modifications or the conversion may not be feasible.

Egress is a critical life-safety requirement for bedrooms. Every bedroom must have at least one egress window that can be opened from the inside without tools or special knowledge. The minimum openable area of the egress window must be 0.35 square metres (approximately 3.77 square feet), with no dimension less than 380 millimetres (15 inches). This allows a person to escape and a firefighter to enter in an emergency. Most garage doors will be removed and the opening framed in with a combination of wall framing, windows, and possibly a new entry door — at least one of those windows must meet egress requirements. In Miramichi's cold climate, choose windows with a minimum Energy Star Zone 3 rating and install them with proper flashing and air sealing.

Fire separation requirements depend on whether the garage is attached or detached. If the garage is attached to the house, the existing 45-minute fire-rated separation between the garage and the dwelling must be addressed. If you are converting the entire garage to living space and eliminating the garage function, the fire separation wall between the former garage and the house may be reclassified — but this must be confirmed with the building inspector. If any portion of the space retains garage use (for example, keeping one bay as a garage and converting the other to a bedroom), the full fire separation must remain intact with 5/8-inch Type X drywall, fire-rated doors, and fire-stopped penetrations. A detached garage conversion has simpler fire separation considerations but must still meet the minimum fire-resistance rating for its construction type.

Insulation and heating must bring the space up to current NB energy code standards. For a bedroom conversion in Miramichi — where winters regularly reach -25 to -30 degrees Celsius and the frost season is long — walls should be insulated to a minimum of R-20 and the ceiling to R-32 or higher. A proper vapour barrier (6-mil poly on the warm side of the insulation) is essential to prevent condensation within the wall and ceiling assemblies. The concrete slab floor, which was likely poured without insulation or a vapour barrier, will need a moisture management strategy — typically a dimpled membrane topped with rigid foam insulation and then a subfloor or floating floor system. Heating can be provided by extending the home's existing HVAC system (if capacity allows) or by installing a ductless mini-split heat pump, which costs $3,500 to $6,000 installed and provides both heating and cooling.

Electrical requirements for a bedroom include a minimum of one duplex receptacle on each wall, with receptacles spaced no more than 3.6 metres (12 feet) apart. All circuits must have proper arc-fault circuit interrupter (AFCI) protection, which is now required for bedroom circuits under the current code. Smoke detectors must be installed inside the bedroom and in any hallway leading to it. If the garage is attached, a carbon monoxide detector is also required. All electrical work must be done by a licensed electrician with an electrical permit — this is separate from the building permit.

Ventilation is required in all habitable rooms. The bedroom must have either operable windows providing natural ventilation or a mechanical ventilation system. Given Miramichi's cold winters, a heat recovery ventilator (HRV) connected to the home's ventilation system is the ideal solution, providing fresh air without significant heat loss.

This conversion requires a building permit, a licensed electrician, and a contractor experienced with NB Building Code residential requirements. Do not attempt to convert a garage to a bedroom without permits — unpermitted bedroom conversions create serious liability, insurance, and resale problems. Get matched with qualified local contractors through New Brunswick Garages, a free service of the New Brunswick Construction Network.