A renovation often starts with an exciting idea: a better kitchen, an extra room, a repaired roof or a more practical family home. Problems begin when the idea is not translated into a detailed scope, realistic budget and clear responsibility.
The best contractor is not automatically the one with the lowest quote or the most polished social-media page. You need a contractor whose experience fits the project, whose paperwork is clear and whose process protects both parties when something changes.
Follow these steps before handing over a deposit or allowing demolition to begin.
1. Define what you are actually asking contractors to price
Three contractors cannot produce comparable quotes if each one is imagining a different result. Start with a written brief that describes the rooms, measurements, finishes and work you expect.
Include details such as:
- demolition and rubble removal;
- structural alterations;
- plumbing and electrical changes;
- waterproofing;
- ceilings, flooring and painting;
- cabinets, sanitaryware and fittings;
- municipal approvals or professional drawings; and
- protection of occupied areas.
Use the same brief for every contractor. If selections are not final, label them as provisional rather than pretending they are fixed.
2. Match the contractor’s experience to the project
A team that performs excellent painting and tiling may not be equipped to remove a load-bearing wall or coordinate a complex extension. Ask for recent examples that resemble your project in scale and technical difficulty.
Request contactable references and ask previous clients about:
- whether the team arrived consistently;
- how changes were priced;
- whether the site was kept safe and tidy;
- whether the final account matched the agreement; and
- how defects were handled after completion.
Visit a completed project if the client agrees. Photographs are helpful, but an in-person view can reveal finishes, alignment and attention to detail.
3. Check registration, approvals and professional roles where relevant
Requirements depend on whether the work is maintenance, an alteration, an addition or the construction of a new home. Do not assume every renovation falls under exactly the same process.
For work within the NHBRC’s mandate, verify the home builder’s registration through the official NHBRC builder verification service. The NHBRC also advises consumers to see a current registration certificate, inspect completed homes, speak to previous clients and insist on a contract.
Ask the contractor and, where necessary, your municipality or appointed professional:
- Are building plans or municipal approval required?
- Is an architect, architectural professional or engineer needed?
- Does the project need NHBRC enrolment or another process?
- Who will arrange inspections?
- Which plumbing or electrical certificates are required?
A responsible contractor should not discourage you from checking. If the answer is uncertain, obtain confirmation before work starts.
4. Compare detailed quotes, not headline totals
Renovation quotes should explain what materials and labour are included. Look for quantities, allowances, brands or quality levels where those details matter.
Check whether the quote covers:
- site establishment and protection;
- labour and supervision;
- delivery and storage;
- waste and rubble removal;
- subcontractors;
- testing and compliance certificates;
- making good after plumbing or electrical work;
- VAT; and
- exclusions.
Be especially careful with “PC items” or provisional sums. These are allowances, not guaranteed final prices. Ask what happens if the item you select costs more or less.
Use our service quote comparison guide to normalise competing quotes before deciding.
5. Put the agreement and payment schedule in writing
A written contract should identify the parties, address, scope, price, start date, estimated completion, payment stages and process for changes.
Avoid a payment schedule based only on calendar dates. Tie meaningful payments to visible milestones that can be checked, such as completion of approved demolition, first-fix services, waterproofing tests or installed finishes.
Deposits may be needed for mobilisation or specially ordered materials, but a request for most or all of the project value upfront deserves careful scrutiny. Ask for proof of major material orders and keep payment records.
The NHBRC’s consumer guidance recommends ensuring the builder provides a contract and carefully inspecting its terms and conditions.
6. Agree on a written change-order process
Renovations uncover surprises. Old plumbing may be corroded, walls may hide damage or a chosen item may become unavailable. The goal is not to pretend changes will never happen; it is to control how they are approved.
Require every variation to show:
- what changed and why;
- the additional or reduced cost;
- the effect on the completion date; and
- both parties’ approval before the changed work proceeds.
Do not rely on memory or a rushed conversation on site. A short written variation prevents the final account from becoming a collection of disputed extras.
7. Clarify insurance, site safety and responsibility for damage
Ask what insurance the contractor holds and who is responsible if work damages the existing property, a neighbouring property or common-area infrastructure.
Discuss:
- access and keys;
- safe storage of tools and materials;
- dust and weather protection;
- working hours and neighbour rules;
- supervision of workers and subcontractors;
- children, pets and occupied rooms; and
- security at the end of each day.
For hazardous materials, structural work or other higher-risk tasks, obtain specialist advice rather than relying on a general renovation team.
8. Inspect the work in stages and keep evidence
Do not wait until the final day to inspect everything. Photograph hidden services before they are closed, keep product specifications and record decisions.
Create a snag list near completion. List each item clearly, agree who will fix it and record the target date. Hold an appropriate final amount until the agreed completion and handover conditions are satisfied, subject to your contract.
Collect warranties, manuals, invoices, approved plans and compliance certificates in one handover folder.
Renovation contractor warning signs
Pause before appointing a contractor who:
- refuses to provide a detailed written scope;
- cannot show suitable previous work;
- uses pressure to secure an immediate large deposit;
- suggests avoiding approvals without checking whether they apply;
- changes bank details without a verified process;
- asks you to pay subcontractors unexpectedly;
- repeatedly changes the price without written variations; or
- cannot explain who will supervise the site.
One warning sign may have an innocent explanation. Several together justify a second opinion.
Frequently asked questions
Should I get three renovation quotes?
Three comparable quotes can be useful, but quality matters more than the number. Give each contractor the same brief and clarify differences before comparing prices.
Does every renovation contractor need NHBRC registration?
The correct requirement depends on the nature and legal scope of the project. NHBRC registration and enrolment rules apply to home building within its mandate, while maintenance and alterations may involve different requirements. Confirm with the NHBRC, municipality or an appropriate professional for your specific project.
How much deposit should I pay?
There is no single percentage that safely fits every renovation. Consider the contract, genuine mobilisation costs and specially ordered materials. Avoid paying a disproportionate share before equivalent value has been delivered, and never pay into changed banking details without independent verification.
What if the contractor finds hidden damage?
Ask for evidence and a written variation showing the work, price and time impact. Obtain specialist input or another quote if the issue is substantial.
Build the project on clear decisions
A reliable contractor welcomes a clear scope because it reduces disputes for everyone. Take time to verify experience, compare like-for-like quotes and document changes before they become costs.
Browse home and service businesses on Find At Home and create a shortlist for your project.
This article is general guidance, not legal, structural or building-compliance advice. Confirm the requirements for your property and project with the relevant municipality, regulator and suitably qualified professional.
