Fire separation
The one that makes attached secondary dwellings genuinely different from detached ones.
If your secondary dwelling is attached to the principal dwelling, or close to it, fire-separation requirements under the National Construction Code come into play. Detached builds with adequate separation generally avoid this.
This is a construction requirement, not just a paperwork one — it changes wall build-ups, and therefore cost, and therefore your budget.
How the answer is determined for your site — locked
What to ask, and who to ask — locked
How this area costs people money — locked
Pay once, everything is yours
Setbacks & LEP, fire separation, BASIX/NatHERS and bushfire BAL — plus the refusal-reasons checklist, the document checklist, and the full roadmap and budget detail.
Confirm this yourself
Fire separation is safety-critical and must be confirmed by your registered certifier or building surveyor for your specific design. Nothing on this page substitutes for that, and it is not intended to.