Smoke Alarms & NZBC Clause F7

NZBC clause F7 Warning Systems requires household units to have working smoke alarms, and the Acceptable Solution F7/AS1 (together with NZS 4514 for the alarms themselves) sets the type, placement and power. The aim is simple — wake sleeping people early enough to get out.

Key requirements

• Photoelectric type is required under F7/AS1 — it responds to smouldering smoke better than the old ionisation type and nuisance-trips less.
• Placement: every bedroom, every hallway and every level, kept 3 m from a cooking appliance to reduce nuisance alarms.
• Power: hardwired to mains with a 10-year sealed lithium battery backup, or a 10-year sealed battery as the primary supply.
• Interconnected — if any one trips, they all alarm (NZS 4514 + F7/AS1 best practice).
• Mounting: on the ceiling, ≥300 mm from any wall or corner; alternatively on a wall 300–500 mm down from the ceiling if the ceiling is over 2.7 m.
• Upkeep: test monthly and replace every 10 years (a sealed lithium unit means replacing the whole alarm).
• Premium photoelectric units add temperature (heat) sensing — useful for kitchens and garages.

Why photoelectric, not ionisation

Most fatal house fires start as slow smouldering fires — couch, bedding, electrical. Photoelectric alarms detect that visible smoke far sooner than the old ionisation type, and they nuisance-trip less near kitchens, so people are less tempted to disconnect them. That’s why F7/AS1 calls for photoelectric, and why older ionisation alarms aren’t acceptable for new installs — swap them out during any renovation.

Placement in plain terms

Put alarms in or within 3 m of every bedroom door, in every hallway or living space serving bedrooms, and on every level. Fix them to the ceiling, ≥300 mm off any wall or corner (that’s the dead-air pocket), and keep them ≥3 m from the cooktop to cut nuisance alarms. Interconnect them so one trip sounds them all — vital in a two-storey or spread-out plan.

Rentals: a separate legal duty

Under the Residential Tenancies Act, landlords must provide working photoelectric long-life (10-year) or hardwired smoke alarms — within 3 m of each bedroom door and on every level. This duty is separate from the Healthy Homes Standards (which don’t cover alarms) and separate from F7 at consent. Compliant smoke alarms are still required in rentals — the Healthy Homes heating requirement doesn’t replace F7/AS1.