The Costs Nobody Mentions Until You Have Signed
Most knockdown rebuild quotes cover the obvious — demolition and construction. But KDR projects have a range of additional costs that can add $50,000 to $150,000 if you do not budget for them upfront. Buildana (Lic. 487805C) includes most of these in our fixed-price contracts, but not every builder does. Here are the hidden costs that catch homeowners off guard in Western Sydney.
Asbestos — The Cost That Surprises Everyone
Almost every home built before 1990 in Western Sydney contains asbestos. Fibro eaves, bathroom wall linings, vinyl sheet flooring, cement sheeting, and even some roof materials used asbestos-containing products. The presence of asbestos is not the surprise — the cost of removing it is.
Non-friable (bonded) asbestos removal by a Class B licensed removalist: $5,000–$12,000 for a typical house. Friable asbestos requiring a Class A removalist with full containment and air monitoring: $10,000–$25,000.
The problem arises when a builder provides a demolition quote 'subject to asbestos assessment' — you accept the quote thinking it covers everything, then receive a variation notice for $15,000 after the assessment reveals asbestos throughout. Buildana includes asbestos assessment in every KDR quote. If asbestos is found, removal costs are included in your fixed price — not treated as a surprise extra.
Site Costs — Soil, Slope, and Rock
Your block is not the same as the display village block. Site costs cover the difference between a flat, stable building platform and your actual site conditions.
Reactive soil: Much of Western Sydney sits on clay soils classified as H (highly reactive) or E (extremely reactive). These soils expand and contract with moisture changes, requiring engineered raft slab or pier foundations instead of a standard waffle pod. Additional cost: $10,000–$30,000.
Rock: Sandstone and shale formations are common in parts of Fairfield, Liverpool and Canterbury-Bankstown. If rock is encountered during excavation, it must be broken or removed. Cost: $100–$250 per cubic metre — and a typical house slab may require 50–200 cubic metres of excavation. Total: $5,000–$50,000.
Slope: Blocks with a fall of 2m or more across the building area need retaining walls and benching. Based on Rawlinson benchmarks, expect $30,000–$80,000 for significant slope management.
Many project home builders exclude site costs from their advertised price. At Buildana, a geotechnical report is ordered during the design phase — well before you sign a construction contract.
Council Costs You Cannot Avoid
Council fees are mandatory and vary significantly between Western Sydney councils:
Section 7.11/7.12 contributions (infrastructure levies): • Fairfield City Council: $15,000–$25,000 for a new dwelling • Liverpool City Council: $20,000–$40,000+ (one of the highest in Western Sydney) • Cumberland Council: $15,000–$25,000 • Canterbury-Bankstown City Council: $20,000–$35,000 • Blacktown City Council: $15,000–$30,000
Long service levy: 0.25 per cent of total construction cost. On a $600,000 build, that is $1,500.
CDC or DA fees: CDC costs $3,000–$6,000 through a private certifier. DA costs $5,000–$15,000 through council plus any consultant reports required (traffic, heritage, acoustic, arborist).
Sewer and water connection fees: Sydney Water charges $3,000–$8,000+ for new connections. Stormwater compliance may require an on-site detention system — $5,000–$15,000.
These costs are rarely optional and rarely included in builder advertising. They add $25,000–$60,000 to almost every KDR project.
Holding Costs — The Invisible Budget Blowout
You cannot live in a house while it is being demolished and rebuilt. You need alternative accommodation for 10–14 months.
Rental accommodation: $500–$700 per week in Western Sydney = $26,000–$40,000 for 12 months.
Storage: furniture and belongings in storage while you are renting = $200–$400 per month = $2,400–$5,600.
Insurance: you still need building and contents insurance on the vacant land and any stored materials during construction. Typically $1,500–$3,000 per year.
Loan interest: if you have a mortgage on the property, you continue paying interest during construction. If you also take out a construction loan, you may be paying interest on both — a period of 'double interest' that costs $1,000–$3,000 per month depending on loan sizes and rates.
Total holding costs for a typical 12-month KDR: $35,000–$55,000.
The biggest holding cost variable is timeline. A DA that takes 4 months instead of 2 months adds $6,000–$10,000 in holding costs. This is why Buildana always recommends CDC approval where eligible — it is faster, cheaper, and more predictable.
