Partial demolition covers any job where part of the structure stays and part is removed. It's harder than a full knockdown because the remaining structure must be protected, propped where needed, and weatherproofed.
Common Partial Demolition Scopes
- Back of house removal for an extension
- Garage demolition (attached or detached)
- Second-storey removal (going back to single-storey)
- Internal wall removal (load-bearing or non-load-bearing)
- Front facade retention (heritage) with back-half demolition
- Roof-only removal
Typical Cost in Sydney (2026)
- Garage demolition: $3,500–$8,500
- Back-of-house removal (small extension footprint): $8,000–$18,000
- Major rear half demolition: $15,000–$35,000
- Second-storey removal: $25,000–$55,000
- Internal wall removal (non-load-bearing): $1,800–$4,500
- Internal wall removal (load-bearing, with steel beam): $5,500–$15,000
Ranges depend on size, asbestos content, access, propping requirements and waste classification. Partial demolition usually costs 30–60% more per square metre than a full knockdown because you can't just push a wall over.
Structural Engineer Involvement
Most load-bearing partial demolitions need a structural engineer's drawings before work starts. The engineer specifies temporary propping, beam sizes, and the demolition sequence. Budget $800–$2,500 for engineer design.
Weatherproofing the Remaining Structure
Once part of the house is open, rain protection becomes critical. Options:
- Temporary tarps and battens (cheapest, 1–4 weeks)
- Hoarding with shadecloth across the open face
- Sequencing demolition + new construction to minimise exposure
What to Send for a Partial Demolition Quote
- Architectural plans showing what stays vs goes (coloured/marked-up)
- Structural engineer's demolition sequence if available
- Photos of all sides of the house, plus the area being removed
- Property access photos (driveway width, gates, easements)
- Any known asbestos (fibro eaves, vinyl floor, fence sheets)
Frequently Asked Questions
Do I need council approval for partial demolition?
Yes, in most cases. Internal-only non-structural strip-outs may not need a CDC, but anything that touches the external envelope or a load-bearing element does.
Can the same crew do the partial demolition and the rebuild?
Demolition contractors don't normally build. But Direct Demolition coordinates with your builder so the handover is clean — propping in place, debris cleared, site ready.
How long does partial demolition take?
Garage: 1–2 days. Back-of-house: 3–6 days. Second-storey removal: 5–10 days. Internal walls: 1–3 days.