How Long Does a Knockdown Rebuild Take in NSW?

The question every couple asks before they sign a knockdown rebuild contract is the same: how long is this going to take? We have walked roughly 60 KDR projects through to completion since 2021, so this guide is built on what those projects actually showed, not a sales brochure.

The realistic full timeline

A typical Western Sydney KDR takes 12 to 18 months from first site visit to keys in hand. Here is how that breaks down by stage.

Stage 1: Site visit and feasibility (1 to 2 weeks)

We come to your block, photograph the existing house, measure setbacks, check easements, sewer access and tree protection orders. You get a feasibility report and a price range for the rebuild. If you are good to proceed, we move to design.

Stage 2: Design and contract (5 to 10 weeks)

Floor plan, facade, inclusion selections, engineering preliminaries. The longer end of this range is for clients customising heavily. Project-home builds settle quickly. Custom Master Craftsmen projects can run 12 to 16 weeks at this stage because every detail gets specified.

Stage 3: Approvals and disconnections (6 to 14 weeks for CDC, 14 to 30 weeks for DA)

This is the swing factor. A clean CDC under the State Environmental Planning Policy typically clears in 6 to 10 weeks. A DA in a difficult council (Hornsby, Hills Shire on a heritage-adjacent block, anything bushfire) can run 6 months or more.

Concurrently we disconnect power, gas, water and NBN from the existing dwelling. The utility providers can take 4 to 8 weeks to issue disconnection certificates, so we start that early.

Stage 4: Demolition and site prep (3 to 5 weeks)

Asbestos audit, neighbour notification, licensed demolition crew, removal of slab and driveway, sediment control, bulk earthworks. If asbestos is present in unexpected quantities (eaves, fibro cladding, electrical lining boards) it can add 1 to 2 weeks.

Stage 5: Construction (28 to 44 weeks)

The actual build follows our standard seven-stage process: slab (3 to 4 weeks), frame (3 to 5 weeks), lockup (4 to 6 weeks), fitout (6 to 8 weeks), then handover preparation. Single-storey project homes finish faster, double-storey custom builds run longer.

Where the time really goes

Most clients underestimate the front end of the timeline. They imagine demolition happening in week 4. In reality, demolition is around week 12 to 24 of the journey. Here is where time actually goes in a typical 14-month project:

• Pre-build (feasibility to demolition complete): 5 to 7 months.
• Build (slab to handover): 7 to 11 months.

The pre-build phase is mostly waiting (for council, for utilities, for engineering) interspersed with decisions you need to make (facade, kitchen, bathrooms). Most of your work as the homeowner happens in this front half.

What you can do to shorten the timeline

• Choose CDC over DA if your block qualifies. CDC saves 8 to 16 weeks. The major constraint is whether your block sits cleanly inside the State Environmental Planning Policy criteria.
• Make selection decisions early. Drag your feet on tile or facade selections and you push the entire schedule.
• Do not change scope after contract signing. A variation in the middle of fitout can add 4 to 8 weeks while the builder reorders materials.
• Get finance pre-approved before contract. Bank delays during the build (waiting on a valuation, waiting on a release of funds) cause progress payment delays that can stop the site for 1 to 3 weeks at a time.
• Use the same builder for design and construction. Going to an external architect, then trying to find a builder, adds 2 to 6 months easily.

What you cannot control

• Council DA processing time.
• Adverse weather. NSW Building Code allows builders 1.5 days extension per day of adverse weather.
• Utility disconnection lead times.
• Material delays for specific products (occasionally European appliances or specialty stone has 8 to 16 week lead times).

The realistic month-by-month example

Here is a real 14-month KDR we delivered in 2024, anonymised:

• Months 1 to 2: Site visit, design.
• Months 3 to 4: Contract, CDC lodgement, utility disconnection.
• Month 5: CDC approval, demolition.
• Months 6 to 7: Slab, frame.
• Months 8 to 9: Lockup (brickwork, windows, roof).
• Months 10 to 13: Fitout (plasterboard, kitchen, bathrooms, painting, flooring, electrical, tiling).
• Month 14: Pre-handover inspection, defects rectification, handover.

Final word from the site team

The single biggest predictor of an on-time KDR is honest communication early. If you tell us upfront you want premium European appliances with 14-week lead times, we plan the build around that. If you spring it on us at fitout stage, the schedule moves. Builders who promise 8-month timelines on every job are almost always overcommitting on the front end and recovering during the build by cutting corners. Real Western Sydney KDRs take 12 to 18 months.