Decision guides
Hidden Costs in Renovation Quotes
Updated 11 June 2026 · 5 min read · Written for Australian homeowners and builders
Renovation budgets rarely blow out because of one big number. They die by a thousand small variations, allowances and exclusions that were always lurking in the quote.
The 10 most common hidden costs
- Demolition and waste disposal — often excluded; budget $2–6k for a mid-size reno.
- Scaffold and edge protection — mandatory for two-storey work.
- Council fees, soil tests, surveys — sometimes called "consultants" and quietly excluded.
- Service connections — water, sewer, NBN, power upgrades.
- Asbestos and lead paint testing & removal — pre-1990 homes almost always have something.
- PC sums set artificially low — see bathroom renos.
- Make-good — patching, painting, skirting after trades.
- Allowance for rotten timber / hidden defects — common in older homes.
- Temporary accommodation — kitchen/bathroom downtime.
- Final clean — surprisingly often excluded.
- ☐I have a written list of exclusions for every quote
- ☐PC sums are realistic for the spec I actually want
- ☐I have a 10–15% contingency above the quote total
- ☐Variation procedure is documented (price + my written approval)
- ☐Final clean and waste removal are explicitly priced
Frequently asked questions
- What contingency should I budget?
- 10% for new builds with no unknowns; 15–20% for renovations of older homes.
- Can I refuse a variation?
- Yes — variations need your written approval before work proceeds. Unapproved variations are difficult to enforce.
- Are PC sums refundable if I spend less?
- Yes — if you go under the allowance, the difference comes off your bill. Make sure that's in writing.
Stop guessing whether a quote is fair
QuoteSift reads up to five quotes at once and produces a plain-English report: what's missing, what's inflated, what the best-value option actually is.
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