The 7 Hidden Costs Every Sydney Builder Forgets to Tell You

The quote looks good. The inclusions list looks thorough. You're about to sign — and then somewhere between slab and lockup, you're $80,000 over budget and wondering what happened.

This is not rare. It's the single most common complaint in residential construction. Here's what builders routinely leave out of their initial pricing.

1. Soil Testing and Geotechnical Reports

Every build requires a soil report. If a builder quotes you without one, they're using assumptions — and assumptions cost you money when those assumptions are wrong. Rocky ground, high water table, reactive clay — none of this is visible until you dig. Budget $2,500–$7,000 and get the report before you compare quotes.

2. Council Fees and Contributions

Section 7.11 contributions (formerly Section 94) can add $15,000–$40,000 to a project in some Sydney LGAs. These are infrastructure levies paid to council — they're not negotiable, and some builders quote without them. Ask for a fee estimate from your council before signing any contract.

3. Site-Specific Costs

Sloping blocks, narrow access, and rock excavation are all charged as extras in most contracts. A provisional sum of $5,000 for rock removal sounds fine until there's solid sandstone 600mm below the surface. The variation that follows is not small.

4. Hydraulic and Structural Engineering

Required on virtually every project but often listed as a provisional sum rather than a fixed cost. Expect $4,000–$12,000 and confirm the scope is fixed before signing.

5. Temporary Services and Fencing

Temporary power, water connection, site fencing, and amenities are builder obligations but often not priced into a base quote. Small individually — $8,000–$15,000 combined on a standard residential build.

6. Demolition (on KDR Projects)

If you're knocking down, demolition is often listed separately or at a rate that doesn't account for asbestos removal. Asbestos discovery mid-demolition is a budget event. Get an asbestos assessment on any pre-1990 home before you commit to a demo price.

7. Landscaping, Driveway and External Works

Almost universally excluded from building contracts. A finished home without a driveway, turf, or fencing isn't a finished home. Budget $25,000–$70,000 depending on block size and what you want at handover.