What are the electrical code requirements for a secondary suite or in-law apartment in New Brunswick?

Secondary suites (also called in-law apartments, granny flats, or accessory dwelling units) are increasingly popular across New Brunswick — driven by housing shortages, aging parents needing nearby care, and rental income potential. The electrical requirements for a legal secondary suite are substantial and represent one of the more complex residential electrical projects.

NB Building Code and Zoning Context

Before diving into electrical requirements, understand the regulatory framework:

• New Brunswick adopted the National Building Code of Canada (NBC) as its provincial building code, with some local amendments
• Secondary suites must comply with Part 9 of the NBC (housing and small buildings)
• Municipal zoning must allow secondary suites — Moncton, Fredericton, Saint John, Dieppe, and Riverview have all updated zoning to permit secondary suites in certain residential zones, but restrictions vary
• A building permit from your municipality is required, which triggers electrical, plumbing, and building inspections
• TSANB electrical permit is required for all electrical work in the suite

Electrical Service Requirements

Separate or Shared Service?

Option 1 — Separate electrical meter and panel (recommended for rental suites):

• The suite gets its own electrical meter, its own panel, and its own NB Power account


• Requires NB Power to install a second meter base (or a multi-meter stack)


• The tenant pays their own electricity — eliminates disputes and simplifies landlord accounting


• Requires adequate service capacity — you may need to upgrade from 200-amp to a 320-amp or 400-amp service to feed both units, or install a separate 100-amp service for the suite


• Cost for separate meter/panel: $3,000–$6,000 (panel, meter base, service entrance work, NB Power coordination)

Option 2 — Shared service with sub-panel:

• The suite is fed from a sub-panel connected to the main home's electrical panel


• One NB Power meter, one bill (landlord pays electricity or includes it in rent)


• Less expensive to install: $1,500–$3,000 for the sub-panel and wiring


• Must verify the main panel has adequate capacity for both units — a load calculation is essential


• Simpler for family situations (in-law suite) where separate billing isn't needed

For rental income properties, separate metering is strongly recommended. NB Power can advise on requirements for adding a second residential meter.

Panel Size for the Suite

• Minimum 60-amp sub-panel for a small bachelor/studio suite (under 500 sq ft) with no electric heat
• 100-amp panel recommended for a one-bedroom suite, especially with electric baseboard heat (common in NB)
• 125–150 amp panel for a larger two-bedroom suite with full kitchen and electric heat

Required Circuits (CEC Minimums)

The Canadian Electrical Code specifies minimum circuit requirements for dwelling units. A secondary suite, even if small, is considered a separate dwelling unit and must meet all CEC dwelling unit minimums:

Kitchen

• Two dedicated 20-amp small appliance branch circuits — these serve only kitchen countertop outlets and dining area outlets (not refrigerator, dishwasher, or lighting)
• One dedicated 20-amp circuit for the refrigerator (recommended, though CEC allows it on a general circuit)
• One dedicated circuit for the dishwasher if installed (20-amp)
• One dedicated circuit for the range/oven — typically a 40-amp, 240V circuit for a standard electric range, or a 20-amp, 120V circuit for a countertop oven in a small suite
• All kitchen countertop outlets must be GFCI-protected
• Outlets within 1.5 metres of a sink must be GFCI-protected

Bathroom

• One dedicated 20-amp circuit for the bathroom outlet(s)
• All bathroom outlets must be GFCI-protected
• Bathroom lighting can share a general lighting circuit (not the bathroom outlet circuit)
• Exhaust fan required by building code — can share the lighting circuit or have its own

Laundry (if included)

• One dedicated 20-amp circuit for the laundry outlet
• One dedicated 30-amp, 240V circuit for the electric dryer (or 120V if gas dryer, rare in NB)

General Circuits

• Bedroom outlets: Minimum one general-purpose 15-amp circuit per room (can be shared across bedrooms/living areas following CEC spacing rules)
• Living room: Outlets on general circuits, spaced per CEC (every 1.8 metres along walls, within 900mm of any door)
• Lighting: Separate lighting circuit(s) — CEC requires switched lighting at every room entrance
• Smoke and CO detectors: Hardwired, interconnected (see Fire Safety section below)

Heating

• Electric baseboard heat circuits: Each baseboard heater typically needs its own dedicated circuit or shares with one other heater. A 1,500W baseboard needs a 15-amp, 240V circuit; larger heaters (2,000W) need a 20-amp, 240V circuit.
• For a one-bedroom suite with baseboard heat in NB, expect 3–5 heating circuits consuming 15–25 amps total at 240V
• Heat pump: If installing a mini-split heat pump (increasingly common and supported by NB Power rebates), a dedicated 20–30 amp, 240V circuit is needed

Hot Water

• If the suite has its own electric water heater: dedicated 30-amp, 240V circuit for a standard 40-gallon tank
• If sharing the main home's water heater: no additional circuit needed (but plumbing code has requirements for shared water systems)

Typical Circuit Count for a One-Bedroom Suite

| Circuit | Amps/Voltage | Count |
|---------|-------------|-------|
| Kitchen small appliance | 20A / 120V | 2 |
| Kitchen range | 40A / 240V | 1 |
| Kitchen fridge | 15A / 120V | 1 |
| Bathroom outlet | 20A / 120V | 1 |
| Laundry outlet | 20A / 120V | 1 |
| Dryer | 30A / 240V | 1 |
| General outlets | 15A / 120V | 2–3 |
| Lighting | 15A / 120V | 1–2 |
| Baseboard heat | 15-20A / 240V | 3–5 |
| Water heater | 30A / 240V | 0–1 |
| Smoke/CO detectors | 15A / 120V | shared |
| Total circuits | | 13–18 |

This is why a 100-amp panel with 20+ spaces is the right starting point for most secondary suites in New Brunswick.

Fire Safety Electrical Requirements

Fire safety is the most critical aspect of secondary suite electrical work:

Smoke detectors:

• Hardwired (not battery-only) with battery backup


• Interconnected — when one alarm sounds, all alarms in the suite sound


• Required in: every bedroom, hallway outside bedrooms, every level of the suite


• Must also be interconnected with the main dwelling's smoke alarms if it's a shared building (so both units are alerted)

Carbon monoxide detectors:

• Required if any fuel-burning appliance serves the suite (gas stove, oil furnace, gas water heater)


• Also required if the suite has an attached garage


• Hardwired with battery backup, interconnected with smoke alarms

AFCI protection:

• Current CEC requires arc-fault circuit interrupter (AFCI) breakers on all circuits serving bedrooms


• AFCI breakers cost $40–$60 each — a notable cost factor when a suite has multiple bedroom circuits

Fire separation:

• The electrical work must maintain the fire separation between the main dwelling and the suite (typically 30-minute or 1-hour fire-rated assembly)


• Electrical boxes in fire-rated walls must be properly installed and firestopped


• Penetrations through fire-rated assemblies must be sealed with approved firestop materials

Costs for Secondary Suite Electrical

| Scope | Cost Range |
|-------|------------|
| Sub-panel only (shared meter) | $1,500–$3,000 |
| Separate meter + panel | $3,000–$6,000 |
| Complete suite wiring (15–18 circuits) | $5,000–$10,000 |
| Electric baseboard heat (3–5 circuits) | $1,000–$2,500 |
| Smoke/CO detector system (hardwired, interconnected) | $300–$600 |
| TSANB permit | $100–$250 |
| Total (complete electrical for 1BR suite) | $8,000–$18,000 |

The wide range reflects the difference between a basic suite (shared meter, minimal finishes) and a fully independent unit (separate meter, full kitchen, in-suite laundry, electric heat).

TSANB Inspection Process

Secondary suite electrical is typically inspected in two stages:

Rough-in inspection: After wiring is run but before drywall is installed. TSANB verifies wire routing, box placement, proper stapling, fire-stopping, and circuit layout.

Final inspection: After all devices (outlets, switches, fixtures, panel) are installed and energized. TSANB verifies everything works, GFCI and AFCI protection is in place, and the installation meets CEC.

Both inspections are included in the permit fee. The rough-in inspection is critical — it's the only time the inspector can see the wiring inside the walls. Missing this inspection means potentially tearing out drywall later if issues are found.

Key Mistakes That Fail Inspection

• Missing GFCI protection in kitchen, bathroom, or laundry
• Missing AFCI protection on bedroom circuits
• Smoke detectors not hardwired or not interconnected
• Fire-rated assembly penetrations not firestopped
• Insufficient outlet spacing (CEC requires outlets every 1.8 metres along walls)
• Kitchen countertop outlets on general circuits instead of dedicated 20-amp small appliance circuits
• Shared neutral between suite and main dwelling circuits (each dwelling unit must have electrically independent circuits)

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