A homeowner is planning a mid-range kitchen renovation and wants a budget range before speaking to builders. They need to know whether $35,000 is realistic or whether they are significantly under budget before engaging anyone.
Budget renovations use standard fixtures and cosmetic changes only. Prestige renovations involve custom joinery, imported tiles, and high-spec appliances.
Always get 3 quotes and add a 15–20% contingency to any renovation budget.
1 What this calculator does
Provides a budget range for common renovation scopes -- kitchen (budget, mid, prestige), bathroom (budget, mid, prestige), living room, bedroom, deck and whole-home renovations. Applies a location multiplier for regional areas. Always returns a low-high range with a recommendation to add 15-20% contingency.
2 Formula & professional reasoning
Budget range = [Low, High] for the selected scope x Location multiplier
Kitchen ranges: Budget $12K-$22K | Mid $22K-$48K | Prestige $48K-$120K
Bathroom: Budget $9K-$16K | Mid $16K-$35K | Prestige $35K-$70K
Deck: Budget $8K-$20K | Mid $20K-$50K
Whole home: Budget $50K-$120K | Mid $120K-$280K | Full $280K-$600K
Add 15-20% contingency to any renovation budget
Renovation costs are expressed as ranges rather than single figures because the variation within any scope is genuinely large -- a budget kitchen at $12K uses flatpack cabinetry and laminate benchtops, while a budget kitchen at $22K uses assembled joinery and stone benchtops. The ranges reflect real market variation in contractor pricing, specification level and site conditions. A 15-20% contingency is higher than for new builds because renovations invariably reveal unexpected conditions -- deteriorated waterproofing, asbestos, substandard previous work -- that are not visible before work starts.
3 Worked examples
⚠️ Illustrative example only — not clinical or professional instruction.
Range: $22,000 to $48,000 | Midpoint: $35,000 | With 15% contingency: $25,300 to $55,200Range: $35,000-$70,000 x 1.12 = $39,200-$78,400 | With 15% contingency: $45,080-$90,160Range: $120,000 to $280,000 | $200,000 sits near the midpoint | With 15% contingency need: $200,000/1.15 = $173,913 budget ex-contingency4 Sanity check
5 Common errors
| Error | Cause | Consequence | Fix |
|---|---|---|---|
| Treating the low end of the range as the budget target | Anchoring to the lowest figure in the range | Contractors cannot deliver the scope at the low end without compromising specification or quality -- disputes and variations result | Use the midpoint of the range as the working budget and hold the top end plus contingency in reserve. The low end of the range requires the simplest specification, most competitive market conditions and zero surprises. |
| Not getting licensed contractors for plumbing, electrical and waterproofing | Using unqualified labour to reduce cost | Unlicensed plumbing and electrical work is illegal and void of warranty -- creates safety hazards and problems at resale | Always use licensed plumbers, electricians and waterproofers regardless of the renovation budget. Confirm licences before work starts through the relevant state licensing authority. |
| Not budgeting for building approval on renovations that require it | Assuming minor renovations do not need council approval | Unapproved work discovered at sale or insurance claim -- costly retrospective approval or removal required | Any renovation involving structural changes, extensions, changes to wet areas (in some jurisdictions), new decks over a certain height or area, or change of use typically requires council approval. Check with the local council before starting work. |
| Paying the full contract price upfront | Contractor requests full payment before starting | No leverage if work is substandard or contractor abandons the job | Australian consumer law and most state fair trading legislation limits upfront deposits for home renovation work. A deposit of 5-10% is standard; progress payments tied to completion of defined stages are appropriate. Never pay more than the work completed. |
6 Reference & regulatory links
7 Professional workflow
Common tools used alongside this one: