Most of Williamstown sits inside a heritage overlay administered by Hobsons Bay Council. That doesn't mean you can't extend or modernise — it means the way you do it matters a lot.
What's protected
The street-facing facade, original roof form, chimneys, verandah and any visible side elevation up to the front of the property. Internal layouts, the rear of the house, and anything not visible from the public realm have far more flexibility.
What council actually wants
Sympathetic from the street, contemporary to the rear. A second-storey extension can absolutely be approved if it's set back from the front parapet and clad in a contrasting modern material — that contrast is read as 'honest', not as 'damaging the heritage fabric'.
Realistic timeline
Pre-application meeting: 2–4 weeks to schedule. Planning permit lodgement: 8–12 weeks for a clean application, longer if neighbours object. Building permit afterwards: 2–4 weeks. Plan for 4–6 months of approvals before you break ground.
