Knockdown Rebuild Sydney — Demolish & Build New | giantA
Design and approval services for knockdown rebuild projects across Sydney. Demolition coordination, DA/CDC and new dwelling design under one roof.
Contact UsIs knockdown rebuild right for you?
Consider knockdown rebuild when:
- Your current home is structurally sound but functionally outdated
- You love your location (school zone, proximity to family, mature neighbourhood) but need more space
- Your lot is large enough to accommodate a modern dwelling without losing too much garden
- You want to avoid stamp duty and selling costs of moving
It is usually NOT the best option when the existing home has heritage value, the site has significant slope (expensive retaining), or you're in a rush (the process takes 18–24 months).
Knockdown rebuild costs and timeline
| Stage | Typical NSW range |
|---|---|
| Feasibility + concept design | $3,000 – $8,000 · 4–6 weeks |
| Architecture + DA/CDC documentation | $12,000 – $27,000 |
| Demolition + site prep | $20,000 – $50,000 |
| Approvals (CDC or DA) | CDC 2–4 weeks / DA 6–16 weeks |
| Construction | $350,000 – $800,000 · 12–18 months |
Our knockdown rebuild process
- Feasibility: site analysis, LEP/DCP check, demolition feasibility, tree protection assessment
- Concept design: floor plans, 3D renders, material palette — your vision with council compliance
- Documentation: complete DA or CDC package, BASIX, consultant coordination
- Demolition coordination: we liaise with demolition contractors and council for demolition permit
- Construction certificate: final technical details, builder-ready documentation
Frequently Asked Questions
What is a knockdown rebuild in NSW?
A knockdown rebuild involves demolishing an existing dwelling and constructing a new home on the same lot. Unlike buying vacant land, you already own the site — but you must obtain a demolition permit and a new DA or CDC for the replacement dwelling. The existing dwelling must be genuinely demolished, not just partially altered.
Do I need DA or CDC for a knockdown rebuild?
If the new dwelling fully complies with the Housing SEPP 2021 standards (height, setbacks, site coverage, FSR), a CDC can be issued in 2–4 weeks. If it doesn't comply — for example, because of a steep slope, heritage controls or non-compliant setbacks — a DA is required, taking 6–16 weeks.
How much does a knockdown rebuild cost in Sydney?
Total project cost (demolition + design + construction) typically ranges from $400,000 to $900,000 for a standard 4-bedroom home in Sydney, depending on size, finishes and site access. Architectural documentation and approvals add $15,000–$35,000. Demolition costs $20,000–$50,000.
Can I live on site during a knockdown rebuild?
No — you must vacate the existing dwelling before demolition. Most clients rent nearby or live with family during the 12–18 month construction period. We can coordinate temporary accommodation arrangements as part of project management.
What happens to trees and landscaping during demolition?
Any tree with a trunk diameter of 200 mm+ at breast height (1.4 m) may be protected under your council's DCP. A pre-demolition arborist report identifies protected trees. We design the new dwelling around retained trees to preserve shade, privacy and property value.
How long does a knockdown rebuild take from start to finish?
Typically 18–24 months: 2–3 months design and documentation, 2–4 months approvals, 12–18 months construction. Complex sites, slope, or custom finishes extend this.
Ready to discuss your project?
Talk to our team about your site, timeline and approval pathway. We respond within one business day.
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