The most expensive renovation mistake in Sydney is hiring the wrong contractor. Here are the warning signs most homeowners only spot after the job has already gone wrong — and how to protect yourself before you sign.
TL;DR: The most expensive renovation mistake in Sydney is hiring the wrong contractor. These are the warning signs most homeowners only recognise after the job has gone wrong.
I'm a licensed contractor based in Liverpool, and the first thing I'd check on anyone quoting your job is their licence — including mine. In NSW, any residential building work over $5,000 in labour and materials has to be done by a licensed contractor. That covers nearly every kitchen and bathroom renovation. You can check a licence yourself in two minutes. Go to the NSW Fair Trading website, use the licence check tool, and search the contractor's name or licence number. It tells you whether the licence is current, what class of work it covers, and whether there are any conditions or past disciplinary action against it. Our licence is 383725C — check it. Here's why it matters. Unlicensed work isn't covered by home building compensation insurance, so if the job goes wrong or the tradie disappears, you have almost no protection. You also can't take an unlicensed operator to the NSW Civil and Administrative Tribunal the same way. An expired or wrong-class licence is the same risk dressed up. If someone won't give you a licence number, that's your answer.
A quote that's one number on one line is not a quote you can trust. A real quote is itemised: it spells out demolition, rubbish removal, plumbing, electrical, cabinetry, benchtops, tiling, waterproofing, painting and fit-off as separate lines, so you can see exactly what you're paying for and compare two quotes like for like. Watch for provisional sums and allowances buried in the fine print. A provisional sum is a placeholder — say, '$2,000 allowance for tiles' — and if your actual selection costs more, you pay the difference. Provisional sums aren't dishonest in themselves, but a quote stuffed with them can balloon well past the headline figure once you start choosing real materials. The dangerous one is the cheap quote with no breakdown. When a number comes in well under everyone else's and there's no detail behind it, something's been left out — usually waterproofing, rubbish removal, or proper preparation. You won't find out until you're mid-job. Our quotes are fully itemised before any work starts, so you can change your mind on paper rather than on site. See the kind of work we scope on our <a href="/kitchens">kitchen renovations</a> page.
There are two ways a renovation gets priced: fixed price, or time and materials. You need to understand which one you're signing, because they shift the risk in completely different directions. A fixed-price contract commits the contractor to a set number for a defined scope. If the job takes longer than expected, that's the contractor's problem, not yours. Time and materials means you pay for every hour worked plus the cost of materials, with no ceiling. The contractor carries no risk — every delay, every redo, every slow day is billed straight to you. Time and materials has a place for genuinely unknown work, like opening up an old wall where nobody knows what's behind it. But for a standard kitchen or bathroom renovation, where the scope is clear, fixed price is non-negotiable. If a contractor refuses to commit to a fixed price for a well-defined job, ask why. Usually it means they either can't estimate accurately or they want the freedom to bill more later. Every InsideOut quote is fixed-price for the scope we agree, so the number you sign is the number you pay.
The deposit is one of the clearest warning signs there is. Under NSW law, for residential building work the maximum deposit a contractor can ask for is 10 percent of the total contract price. That's the legal limit, not a guideline. So if someone asks for 40 or 50 percent upfront, they're either breaking the rules or telling you something about their cash position. A large upfront deposit usually means one of two things: the contractor doesn't have the working capital to start your job without your money, or they're building in a cushion in case they walk away. Neither is your problem to fund. A reasonable arrangement is a deposit of 10 percent or less, followed by progress payments tied to completed stages of work — money paid as milestones are actually reached, not before. That keeps the contractor motivated to keep moving and keeps your money tied to results you can see. If a tradie pushes hard for a big lump sum before lifting a tool, slow down and ask why. The honest ones never need to.
A kitchen or bathroom renovation isn't one trade — it's a plumber, an electrician, a tiler, a cabinetmaker and a painter, all needing to turn up in the right order. Someone has to own that schedule. If they don't, you do. Ask the contractor straight out: who manages the project day to day, and who's my single point of contact? If the answer is vague, or it turns out you're expected to coordinate the trades yourself, that's a red flag. Self-managing a reno is where homeowners lose weeks — the tiler can't start until the plumber's been, the plumber's booked solid, the cabinets arrive before the room's ready, and every gap is dead time you're living through. The other cost of no plan is the blame game. When trades are hired separately and something goes wrong at the join between two of them, each blames the other and you're stuck in the middle paying to fix it. We run every job as one team — plumber, electrician, tiler, cabinetmaker and painter all come through us, scheduled in the right order, with one point of contact responsible for the whole result.
Never start a renovation on a handshake. In NSW, any residential building work over $5,000 must have a written contract, and for work over $20,000 the contract has to include specific things by law. A proper contract should set out the full scope of work, the fixed price, the payment schedule, the start and completion dates, the deposit amount, details of the home building compensation cover, and the contractor's licence number. It should also spell out how variations are handled, so any change to the job is agreed and priced in writing rather than sprung on you later. This isn't red tape — it's your protection. Under the Home Building Act, a written contract is what gives you enforceable rights if the work is defective or the job stalls. Without one, proving what was agreed becomes your word against theirs. Any contractor who suggests skipping the paperwork to 'keep it simple' or 'save on costs' is removing the one document that protects you. A signed contract before work begins is not optional, and a good contractor will insist on it just as firmly as you should.
How a contractor communicates before you've paid them anything is the best preview you'll get of how they'll communicate once they've got your deposit. It rarely improves after the contract is signed. If calls go unreturned for days, if the quote takes three weeks and a dozen reminders, if questions get vague non-answers, or if they're hard to pin down for a site visit — that's the easy, courteous phase, when they're trying to win your business. If they're already slow and slippery now, picture chasing them when there's a problem mid-job and they already have your money. Watch for the opposite too: someone who's all charm and big promises but won't put anything in writing. The contractor you want answers your questions clearly, turns up when they say they will, gives you a written quote in a reasonable time, and tells you honestly when something isn't possible or isn't worth the money. Good communication before the job is the single most reliable predictor of a smooth one. If something feels off at the quoting stage, trust it.
Reviews are useful, but only if you read them properly. A wall of five-star reviews that all say 'great job, highly recommend' with no detail can be as much of a warning as a low score — generic praise is easy to manufacture, and a suspiciously perfect record with no critical voices at all is worth a second look. Genuine reviews have texture. They name the actual job, mention how the contractor handled a hiccup, talk about communication and timelines, and read like a real person wrote them. Look for reviews that describe the process, not just the outcome. A handful of detailed, specific reviews tells you more than a hundred one-liners. Don't skip the one and two-star reviews either — they're often the most informative. The question isn't whether a business has any negative reviews; everyone who's done enough jobs has one. The question is how they responded. A defensive, blaming reply is a red flag. A calm, professional response that acknowledges the issue and explains how it was resolved tells you how they'll treat you if something goes sideways on your job. Read those replies closely.
If you're weighing up quotes for a kitchen or bathroom renovation in Sydney and something doesn't sit right, trust that instinct — it's usually picking up on one of the flags above. The good news is that avoiding a bad contractor is mostly about asking the right questions before you sign. We're a family-run, licensed contractor (NSW 383725C) with twelve years of work behind us, fixed-price quotes, one team across every trade, and a written contract before anything starts. If you want a second opinion on a quote you've been given, or a fresh one done properly, call us on <a href="tel:0250000402">02 5000 0402</a> or send through your plans and a few photos. For a sense of what fair pricing looks like, our <a href="/blog/kitchen-renovation-cost-sydney">kitchen renovation cost guide</a> lays out real numbers. No pressure, no obligation. We're Liverpool-based and working right across Sydney.
Go to the NSW Fair Trading website and use the licence check tool, then search the contractor's name or licence number. It takes about two minutes and tells you whether the licence is current, what class of building work it covers, and whether there's any disciplinary history attached to it. In NSW, any residential building work over $5,000 in labour and materials has to be done by a licensed contractor, which covers almost every kitchen and bathroom renovation. If a tradie won't give you a licence number, or the number doesn't check out, walk away — unlicensed work isn't covered by home building compensation insurance, so you'd have very little protection if the job went wrong.
Under NSW law, the maximum deposit for residential building work is 10 percent of the total contract price. That's a legal limit, not a guideline, so any contractor asking for 30, 40 or 50 percent upfront is either breaking the rules or signalling a cash-flow problem. After the deposit, payments should be structured as progress payments tied to completed stages of work — money paid as milestones are actually reached, not in advance. That keeps your money linked to results you can see and keeps the contractor motivated to keep moving. If someone pushes hard for a large lump sum before any work begins, treat it as a serious warning sign and ask exactly why they need it.
In NSW, residential building work over $5,000 must have a written contract, and over $20,000 the contract must include specific items by law. A proper contract should set out the full scope of work, the fixed price, the payment schedule, the start and completion dates, the deposit amount, the home building compensation cover details, and the contractor's licence number. It should also explain how variations are handled, so any change is agreed and priced in writing rather than sprung on you later. Under the Home Building Act, that written contract is what gives you enforceable rights if the work is defective or stalls. Never start a renovation without a signed contract, no matter how much you trust the person.
If a licensed contractor does defective work, you're protected by the statutory warranties under the Home Building Act, which require the work to be done with due care and skill and to be fit for purpose. Your first step is to raise the defects in writing and give the contractor a reasonable chance to fix them. If they won't, you can lodge a complaint with NSW Fair Trading, who can inspect and issue a rectification order, and if that fails you can take the matter to the NSW Civil and Administrative Tribunal. This is exactly why using a licensed contractor with a written contract matters — unlicensed work and handshake deals leave you with almost none of these protections.
Start by checking the licence on NSW Fair Trading, then ask for an itemised, fixed-price quote rather than a single lump-sum number. A trustworthy renovator gives you a written contract before any work starts, asks for no more than a 10 percent deposit, has a clear project management plan with one point of contact, and communicates promptly while they're still trying to win your business. Read their reviews for specific detail and look at how they respond to any negative ones. Above all, trust your instincts at the quoting stage — if someone is slow, vague or evasive before they have your money, that rarely improves once the job is underway.
InsideOut Joinery & Renos is a family-run custom joinery and renovation business based in Liverpool, Sydney NSW 2170, serving homeowners Sydney-wide. Call 02 5000 0402 or email info@insideoutjoinery.au. One team covers every trade, with a typical 3-week turnaround, trade-cost appliances and 12 years of experience. Licensed contractor — licence 383725C, ABN 62 912 909 739.