Encroachment (setback)
A setback encroachment is a building element allowed to project into a required setback zone. State limits, what counts, and how it differs from a boundary encroachment.
Ask Chalkline about this →An encroachment in the planning sense is a building element allowed to project into a required setback zone under the relevant planning rules (DCP, ResCode, or R-Codes). It is the trim, eave, sun hood, or other secondary feature that can sit closer to a boundary than the main building line, within a set maximum.
What can encroach, and by how much
The rules sit in the state instrument, with NSW DCPs, VIC ResCode, and WA R-Codes each setting their own limits. The pattern is consistent (verified 2026-05-28, see setbacks):
| Element | NSW (typical DCP) | VIC (ResCode) | WA (R-Codes) |
|---|---|---|---|
| Eaves and fascias | to 450 mm from side/rear | to 500 mm | to 600 mm |
| Sun hoods and awnings | to 450 mm at side | to 500 mm | to 600 mm |
| Chimneys and flues | 450 mm from boundary | 500 mm | 600 mm |
| Air-conditioning units | 450 mm from side/rear | 500 mm | 600 mm |
The rule of thumb: NSW allows around 450 mm, VIC around 500 mm, WA around 600 mm. Front setbacks have a longer list of permitted projections (porches, entry features, bay windows, sunshades) each with their own depth and width limits, often expressed against the lot frontage.
Two things to watch
- Measure to the outer edge. An eave encroachment is measured from the boundary to the outer edge of the fascia or the gutter, whichever is furthest, not to the rafter tail. Check the eave detail against the setback dimension before framing.
- Encroachment is not boundary encroachment. A permitted encroachment stays inside the lot and projects only into the setback strip. A boundary encroachment is a structure built over the boundary line onto the neighbour’s land, which requires neighbour consent and is a different legal issue entirely (registration, easement, or remedial action).
Why it matters
Get an encroachment dimension wrong and the project either fails at certifier inspection (DTS breach) or has to go through a DA variation to fix. A 600 mm eave that worked in WA does not work at 450 mm from the side boundary in NSW. Confirm the state, the local DCP if NSW, and the specific dimensional limit before signing off the eave detail or the chimney position on the plans.
Also known as: permitted encroachment, setback encroachment, projection into setback.
Category: Planning / setbacks
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See also
Last updated: 2026-05-28. Verified: 2026-05-28. Quarterly review for currency.