VICClass 1aNCC 202527 June 2026
Where do smoke alarms need to go in a new Class 1a house, and must they be interconnected?
A new Class 1a dwelling must have smoke alarms complying with AS 3786 installed: [1]
- on or near the ceiling of every storey;
- in every hallway associated with a bedroom, and between the sleeping areas and the rest of the dwelling where there is no connecting hallway.
The alarms must be connected to mains power and interconnected so that when one activates, all of them sound. [1] [2]
AS 3786 is the product standard the alarms themselves must be certified to — confirm the model you specify carries that certification. [2]
Sources
- 1NCC 2025 Volume Two — ABCB Housing ProvisionsPart 9.5 Smoke alarms · p. 121
- 2AS 3786 — Smoke alarms using scattered light, transmitted light or ionizationReferenced standard · Scope
This answer is for professional reference only and does not replace a registered building surveyor or certifier. The operative edition of the NCC differs by jurisdiction and changes over time. Verify against the current code for your jurisdiction before relying on it.