The wrong granny flat builder can cost you months and tens of thousands of dollars. Asking the right questions on the first call helps you work out which type you’re dealing with.
Verify licence and insurance while you’re still on the phone
Start with credentials. Ask for the builder’s licence number and the name of the regulator you can check it with. Don’t accept a photo of a card or a verbal assurance. Look up the details while you talk.
In NSW, that regulator is NSW Fair Trading. In Queensland, it is QBCC. In Victoria, it is VBA. If the builder hesitates or tells you the number doesn’t matter, end the call.
Then ask about insurance under the Home Building Act 1989 in NSW. For residential work over $20,000, the builder must have Home Building Compensation Fund cover in place before you sign. Ask who holds the policy and request a copy of the certificate. There should be no delay in providing it.
We hear plenty of vague talk about warranties at this stage, but it means little next to your statutory rights. You need specific answers before going any further.
Request a written contract that clearly names the work and the price. It should also cover timeframes and progress claims. We walk away from anyone who wants cash upfront or proposes a handshake deal.
Check how long they have held the licence in this state. A long record of granny flat work beats a fresh licence backed by big claims. You can check licence dates and disciplinary actions online in minutes.
Ask which approval path your block needs
Approvals can make or break a granny flat project. A builder who does this work every week should quickly tell you whether your block is likely to go through a Complying Development Certificate or need a full development application.
The answer depends on lot size and zoning, along with floor area, setbacks, access and services.
Have the builder explain the Housing SEPP 2021 and how it applies to your site. You don’t need a planning lecture. You need confidence that they use this policy regularly and understand where its limits sit.
A single-storey granny flat up to 60 square metres on a standard lot can move through a Complying Development Certificate in as little as 20 days when it meets the standards. That speed is possible only when the builder understands the rules and gets the paperwork right the first time.
Don’t hire someone who is guessing here.
Expect the builder to request a survey, contour plan and sewer details. If they provide a quote without those documents, they are guessing about the slope and services.
Find out who handles the CDC paperwork and who the certifier will be. Then ask what happens if the site fails the CDC rules. A frank explanation of switching to a development application shows they have dealt with the situation before.
Ask about privacy screens and overlooking rules because small lots can trigger them quickly. A builder who identifies these issues early can save you from a redesign. You need that warning before the plans are drawn, not afterwards.
Ask how many granny flats they have actually built
General building experience doesn’t automatically translate to this type of work. Granny flats have tight setbacks and strict site rules, so you need someone who deals with those limits regularly.
Ask how many of their completed jobs were granny flats and how many were full homes. Find out where those granny flats are located and whether you can drive past them. A genuine specialist should answer without hesitation.
Renders always look smooth, while real blocks come with slopes, fences and close neighbours. Ask how the builder manages those constraints on narrow sites.
Setbacks and easements shape every granny flat plan. Fire rules matter as well, and a generalist may overlook those details.
You need evidence from completed sites rather than concept images alone. When assessing a company such as Home and granny flats, ask to see completed projects and, where possible, inspect finished kitchens, laundries and access arrangements. You can also check whether the side access genuinely works for tenants or family members.
Confirm whether they build turnkey on site or supply a kit for someone else to assemble. Both models can work. The problem is vagueness about which one you are buying.
We see granny flats used for older parents, adult children and long-term renters. Ask how each use would change the plan. Door widths and step-free entries matter for ageing in place, while separate metering and sound separation are important for rentals.
When you drive past previous projects, check the rooflines and drainage. Step inside where possible. Tight hallways and poor storage become obvious when a family moves in with real furniture.
We favour plans with level thresholds and wider doors because those details suit older parents now and renters later. Ask what each inclusion costs to upgrade while the walls are still open.
Pin down what the price includes and excludes
Headline prices can be misleading. The written list of inclusions and exclusions is what matters, so request it before discussing upgrades or colours.
That list should cover the slab, site works, connections, council fees, landscaping and fencing. If any of those lines are missing, assume they will cost extra.
Check whether the number is fixed price after a site inspection or cost-plus. A fixed figure means little when it comes from an online form. Insist on a site visit that records soil conditions and access.
Soil class determines the footing design. A careful builder will explain whether your site needs a standard slab or suspended piers. That discussion belongs before you sign, rather than after the excavator arrives.
Many buyers compare potential rent with repayments. Ask which choices will protect the property’s long-term value. Cheap cladding and undersized hot-water systems rarely help.
Watch for provisional sums and prime-cost items, as those lines allow a low quote to rise later. Ask which amounts are fixed and how variations will be priced and approved in writing.
Confirm when progress payments fall due and whether final payment waits until the certifier has signed off and the meters are connected. We prefer that link because it keeps everyone focused through to completion.
Ask how specification choices affect rental returns and upkeep. Durable floors and simple rooflines cost less to maintain, and those savings can improve yield more than fancy tapware.
Ask who does the work and how long it takes
Request a written build timeframe from contract signing through to handover. The builder should also explain what happens when approvals stall or rain stops work, including who carries that risk.
Good builders provide a range with clear reasons for any extensions. Poor builders offer a single date without supporting detail. The difference between those answers is telling.
Find out which trades are employed in-house and which are subcontracted. You also need to know who manages the subcontractors each day. Look for a named project manager who attends the site rather than operating only by phone.
High-volume work often fails because of poor supervision, not poor materials. Ask how many jobs that manager oversees at once and how often you will receive photo updates or attend site walks. Brief or evasive answers tell you plenty.
We raise this point on every job. The builders we trust are comfortable answering it.
Clarify how weather delays are recorded, who will notify you and how quickly they will make contact. We expect a text accompanied by a photo, not a week of silence.
Find out what happens when key materials are unavailable. A straightforward builder will explain possible substitutions and price effects upfront. That honesty is more useful than a vague promise that the dates won’t change.
Don’t rush this part. Ten minutes spent checking now can prevent ten months of disputes later.
Ask for start and finish dates that are tied to approvals rather than contract signing alone. That connection helps prevent idle time while the paperwork moves.
Ask how they handle energy rules and site engineering
Small homes still have to meet energy rules. Ask how the builder will meet BASIX and listen for specific figures rather than slogans.
Check the insulation values allowed for in the walls and ceiling, along with the glazing specification. Then ask how the design handles ventilation and daylight. Vague replies such as “energy compliant” may mean a cheap quote is hiding thin specifications.
Small choices here can affect bills for decades. A builder who puts brands and ratings in the contract is being clear, while one who refuses to record them is not.
Discuss orientation and window placement as well. There is no extra cost to face living areas north where the block allows it. That decision can reduce heat load without lowering quality.
Confirm whether a soil test and contour survey are included. Those reports determine footing depth and drainage falls. Without them, any slab-work quote is only a guess.
Ask how the design limits the amount of west-facing glass. Large western windows can make a small flat very hot in summer. Better plans place more glass to the north and use eaves for shade.
Ask what happens after handover
Discuss defects in plain terms. You are entitled to 6 years for structural defects and 2 years for everything else under the Home Building Act. Any shorter period in the builder’s paperwork is a red flag.
Ask how you lodge a defect, who returns to fix it and how quickly they respond. Good builders use a written process. Others may rely on you eventually giving up, so keep copies of every request.
Check whether you can bring an independent inspector to stage checks. Professional builders generally welcome another set of eyes. Pushback can indicate that a builder is uncomfortable with outside scrutiny.
Ask to visit a granny flat that was completed at least 12 months ago and speak with the owner alone. Renders don’t reveal sticking doors or cracked grout. A year of daily use does.
We learn more from these visits than we do from brochures. Ask the owner what went wrong and how the builder dealt with it.
Confirm which documents you will receive at handover. These should include warranties, manuals and compliance certificates for plumbing and electrical work.
Ask whether you can hold a small sum until minor fixes are completed. Many contracts allow it, and that clause helps turn promises into action.
Keep every message and variation in writing, along with dated photos. If a defect appears in month ten, that file can support your case.
Take these questions into every call and write down the answers. The differences between builders will soon become clear. Choose the one who is specific on paper rather than merely smooth on the phone.
