Short answer
Lot property is the part an owner holds individually — usually the interior of the unit. Common property is everything else: the shared structure and areas (external walls, roof, foundations, common hallways, driveways and shared services), owned jointly by all owners through the owners corporation. The registered strata plan sets the exact boundary between the two.
Why the boundary matters
Knowing which side an item falls on decides who repairs it and who pays. As a rule, the structure and shared services are common property (owners corporation), while the inside of a unit is the lot (owner). Because most “who’s responsible?” questions come down to this one distinction, it’s usually the first thing to establish before anything else. See who’s responsible for strata repairs.
Where the line actually sits
The precise boundary is defined by the registered strata plan for that scheme — it is the final word, not a general rule of thumb. Borderline items often need the plan checked: windows, balconies, pipes and services that run between lots. A by-law can also move responsibility for a particular item, so the plan and the scheme’s by-laws are both worth checking before deciding.
Keeping track of it
For a self-managed scheme, the practical challenge is having the boundary call to hand every time an issue comes up — not re-deciding it from scratch. A system such as Straita lets the committee record each issue against the property it affects and keep that history in one place, so once a grey area is worked out, the decision is documented rather than forgotten.
Primary sources
- Strata Schemes Management Act 2015 (NSW) — meaning of common property and the owners corporation’s duty to maintain it.
- NSW Government — Strata schemes (Fair Trading) — common property, lots and repairs.