A Class 1b boarding house is built under the housing rules of the National Construction Code (NCC), but its fire safety requirements go further than an ordinary home. People who don't know each other sleep under one roof, so the code asks for earlier warning and better help getting out.
Smoke alarms: more of them than in a house
Part 9.5 of the ABCB Housing Provisions sets the rules. Each alarm has to meet AS 3786 and run off mains power if the building is connected. Where a building has two or more alarms, they must be interconnected so they all sound together. In a Class 1b building, alarms are required:
- in every bedroom
- in every corridor or hallway serving a bedroom, or, if there isn't one, in the space separating the bedrooms from the living areas
- on each other storey
That is more than a standard Class 1a house, which doesn't need an alarm inside each bedroom. Placement matters too. Alarms go on or near the ceiling and must avoid dead air spaces, such as tight corners or the very top of a raked ceiling, where hot air can stop smoke reaching the sensor.
Lighting to help people get out
A Class 1b building also needs a lighting system to help occupants find their way out in a fire. It must switch on when the hallway smoke alarm activates. It can be a light built into the alarm itself, or the normal lighting in the corridor or area that alarm covers, wired so the alarm turns it on. The code's explanatory notes warn against using lights on a dimmer or a timer, because they may be too dim or switch off before everyone is out.
Fire separation
Part 9.2 of the Housing Provisions deals with fire spreading between buildings. An external wall needs fire protection if it is less than 900 mm from a side boundary or the rear boundary, or less than 1.8 m from another building on the same allotment (with some exceptions for Class 10 structures that serve the building). Such a wall needs a fire resistance level of 60/60/60, or must be masonry of the required thickness. Openings in that wall need protection too, such as fixed fire windows or self-closing solid core doors. If the boarding house shares a wall with another dwelling, Part 9.3 sets the rules for that separating wall.
Exits and escape paths
The housing provisions don't impose the detailed exit rules of a Class 3 building, such as exit signs or set travel distances. That doesn't make escape planning optional. Good practice for any shared house includes:
- keeping hallways and stairs clear of storage, bikes and furniture
- making sure bedroom and external doors can be opened from inside without a key
- giving residents a simple fire plan showing the way out
If the building grows beyond the Class 1b limits of 12 people or 300 m², it becomes Class 3 and the full exit provisions apply. Only a certifier holding Class 3 registration can take on that work.
Keeping it working
Fire safety only helps if it works on the night. Test alarms regularly, replace them as the manufacturer recommends, and never disconnect one because of nuisance alarms. Find and fix the cause instead. Depending on the approval, there may also be a fire safety schedule listing measures that need regular checks and an annual statement.
Alarms and lighting are checked at the last inspection, before any occupation certificate is issued. To arrange a visit, book an inspection, or read more on our boarding houses page.
Local help across NSW
CertifiBuild certifies Class 1 and Class 10 work in 39 council areas. Local rules on these council pages are a good place to start: Liverpool City Council, Hornsby Shire Council, Campbelltown City Council, Wollongong City Council, North Sydney Council, Woollahra Municipal Council.
Suburb pages with local planning notes: Casula, Cheltenham, Cherrybrook, Claymore, Cleveland, Cremorne Point, Darling Point, Eastwood, Fairlight, Figtree. You can also browse every service area.
Sources
- Alarm and evacuation lighting rules (Housing Provisions 9.5), ABCB
- Fire separation of external walls (Housing Provisions 9.2), ABCB
- Fire safety for houses (NCC 2022 Vol. 2, Part H3), ABCB