Boarding house (Class 1b)
A boarding house is NCC Class 1b: shared lodging for up to 12 unrelated occupants. Stricter smoke alarms, fire separation, plus NSW Housing SEPP land-use controls.
Ask Chalkline about this →A boarding house is a residential building providing shared lodging for up to 12 unrelated occupants, classified as NCC Class 1b. It is distinct from a Class 1a dwelling (a single household residence) and from Class 2 (multi-dwelling apartments). The Class 1b status triggers more stringent fire-and-life-safety requirements than a Class 1a house, plus NSW planning controls under the Housing SEPP 2021.
What pushes a building into Class 1b
- Shared accommodation for up to 12 residents (above 12, the building moves to Class 3).
- Floor area not exceeding 300 m².
- Residents are unrelated (a household with 8 family members is still Class 1a).
- Common entry, common kitchen, or shared bathrooms typically present.
Stricter NCC requirements vs Class 1a
| Requirement | Class 1a (house) | Class 1b (boarding house) |
|---|---|---|
| Smoke alarms | Hallway + storey | Every bedroom + hallway + storey (Part 9.5) |
| Evacuation lighting | Not required | Required in shared corridors and exit paths |
| Fire-rated separation | Wall to garage | Between sleeping rooms; corridor walls fire-rated where required |
| Sanitary facilities | Per-dwelling minimum | Shared facilities sized to occupant load |
| Disability access | Optional | Some pathways need AS 1428 consideration depending on Housing SEPP triggers |
NSW Housing SEPP
In NSW, new boarding houses are also governed by the Housing SEPP 2021 (formerly the Affordable Rental Housing SEPP), which sets density bonuses, minimum room areas, shared-facility ratios, and management-plan requirements. The SEPP prevails over the LEP on the matters it controls.
For a builder
- Confirm the class with the certifier before pricing. Class 1b carries 1a-plus framing, plumbing, electrical scope; pricing a job as 1a and finding out later is expensive.
- Spec smoke-alarm + evacuation-lighting wiring at first fix. Retrofit after rough-in is avoidable cost.
- Co-ordinate NSW planning early. SEPP room areas and ratios often drive the floor plan.
Category: NCC / building classes.
Related
See also
Last updated: 2026-05-29. Verified: 2026-05-29. Quarterly review for currency.