How to quote a building or renovation job
Bathrooms, kitchens, extensions and granny flats. How to scope the job, use allowances properly, stay within deposit caps, and send a quote the customer can follow.
Updated
Renovation quotes are where good builders lose money: a vague scope, an allowance that's too small, or a deposit that's over the legal cap. A clear, staged quote protects you and makes it easier for the customer to say yes.
Scope the job properly
On site, work room by room and trade by trade:
- Demolition and strip-out. What's coming out, skip bins, and whether anything needs asbestos testing (older homes especially).
- Structure. Walls coming out, beams, subfloor condition, roof tie-ins on extensions.
- Services. Plumbing moves, new circuits, gas, drainage. These are licensed trades and usually certified.
- Waterproofing. Wet areas need it to the relevant standard and usually a certificate.
- Finishes. Tiles, cabinetry, benchtops, fixtures, paint.
- Approvals. Council or private certifier, engineering, BASIX in NSW for new dwellings.
How to price the common items
Rough starting prices for common renovation items, ex GST. Every job differs, so use these only as a sanity check against your own costs:
| Item | Rough starting price (ex GST) |
|---|---|
| Bathroom: waterproofing and tiling | from $7,500 |
| Bathroom: plumbing rough-in and fit-off (certified) | from $4,500 |
| Bathroom: electrical (certified) | from $2,000 |
| Bathroom: fixtures and PC items | from $6,500 |
| Bathroom: carpentry, plastering and painting | from $3,800 |
| Kitchen: cabinetry, supply and install | from $16,000 |
| Kitchen: benchtops, supply, fabricate and fit | from $5,500 |
| Strip-out | $1,500 a room |
| Skip bin | $550 each |
| Asbestos sample and testing allowance | $600 |
| Builder or carpenter | $750 a day |
| Labourer | $450 a day |
| Extension build, slab to handover | from $3,200 a m² |
| Granny flat build, slab to handover | from $2,800 a m² |
| Project management and site supervision | $1,500 a week |
Allowances: provisional sums and PC items
You can't price everything on day one. Use:
- Provisional sums for work you can't price yet (rock, rot, structural surprises).
- Prime cost (PC) items for things the customer hasn't chosen yet (tapware, tiles, appliances), at an allowance per item.
Make allowances realistic. A $500 tapware allowance for a customer with $2,000 taste causes an argument later. Several states set rules for how these must be described in residential building contracts, so check yours.
A worked example
A mid-range bathroom renovation:
| Line | Amount |
|---|---|
| Strip-out (1 room) | $1,500.00 |
| Skip bin | $550.00 |
| Waterproofing and tiling | $7,500.00 |
| Plumbing rough-in and fit-off (certified) | $4,500.00 |
| Electrical: lighting, exhaust, heat/light (certified) | $2,000.00 |
| Fixtures and PC items | $6,500.00 |
| Carpentry, plastering and painting | $3,800.00 |
| Subtotal (ex GST) | $26,350.00 |
| GST (10%) | $2,635.00 |
| Total including GST | $28,985.00 |
At this value, the deposit is capped at 10% in NSW ($2,898.50, and only once Home Building Compensation cover is in place) and 5% in Queensland and Victoria ($1,449.25). See deposits for tradies.
Licence, contract and insurance notes
- Licences. Residential building work above a set value needs a licence in most states. For example, NSW requires a contractor licence for residential building work over $5,000, and Queensland requires a QBCC licence for building work over $3,300 (NSW Fair Trading, QBCC).
- Written contracts. Most states require a written contract above set values, with specific content. A quote alone may not be enough.
- Home warranty insurance. Required above set values in most states (for example over $20,000 in NSW) before you take a deposit or start work.
- Licensed trades. Plumbing, gas and electrical must be done by licensed trades and certified.
Check your state's building regulator for current thresholds before you rely on them.
Lay the quote out in stages
Customers find a renovation quote easier to follow when it's grouped the way the job runs:
- Site and preparation: site establishment, protection, skip bins, strip-out.
- Structure: walls, beams, framing, subfloor.
- Services: plumbing, electrical, gas (each certified).
- Wet areas: waterproofing and tiling.
- Fit-out: cabinetry, benchtops, fixtures.
- Finishes: plastering, painting, trims.
- Allowances: provisional sums and PC items, each clearly labelled.
Stages also make progress payments easy to explain: each payment lines up with a stage the customer can see finished.
Show options, not just one price
Renovation customers usually have a budget and a wish list. Pick-one choices (for example "standard tapware or upgraded tapware") and optional extras (heated towel rail, niche, underfloor heating) let them build the job they can afford without you rewriting the quote three times.
Mistakes to avoid
- One big number. Break it into stages so the customer can see what they're paying for and you can schedule progress payments.
- Allowances that are too low. They come back as variations the customer didn't expect.
- Over-cap deposits. Easy to get wrong on bigger jobs.
- No variation process. Agree changes in writing before doing them. See quote vs estimate.
Make it quick to send
Karven lets you start from a starter for your trade or a blank quote, group lines into sections, and choose whether the customer sees the full breakdown, section totals or just the total. They accept online and can pay a deposit by card. See Karven for builders, or grab a free building quote template.
This guide is general information, not legal advice. Check with NSW Fair Trading, the QBCC, Consumer Affairs Victoria or your state's building regulator.
Common questions
- How do builders quote a renovation?
- Break the job into stages or trades (demolition, waterproofing and tiling, plumbing, electrical, fixtures, carpentry and finishes), price each one, and use provisional sums and prime cost allowances for anything you can't price yet.
- What is a provisional sum?
- An allowance for work you can't fully price when you quote, such as rock excavation or repairs found during demolition. The final cost is adjusted to what it actually costs, so explain how that adjustment works.
- How much deposit can a builder take?
- It depends on the state. In NSW the maximum is 10%. In Queensland and Victoria it's 10% for contracts under $20,000 and 5% for $20,000 and over. Check your state regulator for current rules.
- Do I need a written contract for renovation work?
- For residential building work above certain values, most states require a written contract with set content. For example NSW requires one for residential building work over $5,000 and Queensland for domestic building work over $3,300. Check your state's rules.
- Should I include a contingency on a renovation quote?
- Many builders include a clearly labelled contingency or provisional allowance for hidden problems in older homes. Be clear about what it covers and how unused amounts are handled.
Write and send the quote from your phone
With Karven, your customer gets a clear quote, you keep a private breakdown, and a follow-up is ready when a quote goes quiet.
- A clear quote on their phone
- Your private breakdown, kept for later
- Follow-ups Karven writes for you
Free for 21 days, with no card needed.
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