Compare granny flat quotes Frankston

The quote identifies the real builder

The written quote shows the builder’s legal entity, ABN, contact details and Building and Plumbing Commission registration number.
The registration class matches domestic building work for a self-contained second dwelling, not just carpentry, plumbing or drafting.
The quote confirms domestic building insurance will be issued for work over $16,000 before a deposit or progress payment is taken.
The quote names who is responsible for the building permit, planning permit check and final occupancy paperwork.

The scope is specific enough to price

Floor area is stated in m2, with number of bedrooms, bathrooms, kitchen layout and ceiling height.
Inclusions list the actual cladding, roofing, insulation, windows, flooring, tiles, tapware, appliances and paint system.
The site-cost section separates survey, soil test, engineering, excavation, slab, drainage and service runs.
Provisional sums are marked clearly, with realistic allowances instead of $1 placeholders.

The contract money makes sense

GST treatment is stated, so you know whether a $180,000 quote is inclusive or plus GST.
The deposit is no more than 5 percent for a normal granny flat contract over $20,000.
Progress payments align with completed stages, not calendar dates or vague milestones.
Variation wording says changes must be priced and approved in writing before the work proceeds.

Common exclusions have been dealt with

Tree removal, protection zones and arborist reports are included or listed as owner costs.
Switchboard upgrades, metering, solar changes and trenching are priced or allowed for.
Stormwater detention, legal point of discharge and pump-out risk are addressed.
Landscaping, fencing, driveway repairs and clothesline relocation are either included or honestly excluded.

Red flags - walk away if you see these

The builder asks for a 10 percent deposit on a $150,000 to $250,000 domestic building contract.
The quote says "all approvals by owner" but the sales pitch says approvals are easy.
There is no builder registration number, or the number belongs to a different person or entity.
Site costs are listed as TBA after deposit, especially sewer, stormwater, soil and retaining.
The quote is $30,000 to $60,000 cheaper than the others and the missing inclusions are not explained.
You are told a self-contained second dwelling can be built without a building permit.

What a compliant written quote has to state

A useful granny flat quote is not a brochure price. It should identify the builder, the address, the drawings or concept it is based on, the building class, the included floor area, the finish schedule, the permit pathway and the assumptions about the site. In Victoria, work over $10,000 generally needs a major domestic building contract before work starts. Work over $16,000 needs domestic building insurance evidence for the property before money is taken.

The quote should also make clear whether it is a fixed price, an estimate or a preliminary allowance. A fixed-price quote still depends on the documents behind it. If the soil report has not been done, the builder may be able to fix the dwelling price but only allow for the footing risk. That is acceptable if the allowance is clear. It is not acceptable if the quote hides the risk and presents a thin number as complete.

Compare the pricing guide, the site-cost estimator, the one-bedroom service page and the two-bedroom service page while you read quotes. Those pages give you enough context to challenge a missing allowance without sounding like you are guessing.

What is usually excluded and later charged as a variation

The biggest variation risks around Frankston and the Mornington Peninsula are not fancy tiles. They are site conditions. Sewer depth, stormwater detention, reactive clay, buried rubble, old asbestos sheds, tree protection, limited access and switchboard upgrades can each add $5,000 to $30,000. A quote that says "standard site costs included" needs a definition of standard.

Finishes can also be slippery. Builder’s range vinyl plank flooring is not the same allowance as engineered timber. A 600 mm laminate vanity is not the same as a wall-hung stone-top vanity. A standard aluminium window package may not deliver the NatHERS rating on an exposed Mt Eliza or Mt Martha site unless orientation, shading and glazing are considered early.

Some exclusions are fine if they are honest. Many owners prefer to handle fencing, side gates, planting, decks or a new driveway after handover. That can be the cheaper option if cash flow matters. What you do not want is a quote that excludes drainage, approvals or compliance certificates, because those are core parts of a lawful dwelling.

How to check the licence, registration and insurance

Ask for the exact registered builder name, registration number and company entity. Then check the public Building and Plumbing Commission register. Names matter. If the salesperson’s logo is different to the registered builder who signs the contract, ask who is legally responsible for the work, insurance and defects.

For a granny flat, the builder should be able to explain domestic building insurance, the major domestic building contract, the building permit, final occupancy paperwork and the handover certificates for plumbing, electrical, waterproofing and termite management where relevant. You do not need to become a building lawyer, but you do need to know which person is accountable.

Frankston City, Mornington Peninsula Shire and local overlays can change the planning pathway. A small second dwelling may avoid a planning permit in many Victorian circumstances, but a building permit is still required, and planning controls such as overlays, title restrictions and lots under 300 m2 can change the answer. If the project is a dual-occupancy dwelling or subdivision-ready build, treat it as a more involved planning job from the start.

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Quote comparison questions

How many granny flat quotes should I get in Frankston?

Get 2 or 3 written quotes, but compare them against the same scope, drawings and inclusion list. A $165,000 quote can be cheaper than a $145,000 quote if the lower number excludes $25,000 of services, permits and site work.

What deposit can a Victorian builder ask for?

For domestic building work in Victoria, the deposit is capped at 10 percent for contracts under $20,000 and 5 percent for contracts of $20,000 or more. A normal granny flat contract is usually over $20,000, so a deposit above 5 percent should be questioned before you pay.

What must be in a proper written quote?

The quote should state the builder registration details, project address, inclusions, exclusions, permit pathway, site-cost assumptions, GST treatment and progress-payment stages. For work over $10,000 in Victoria, the final agreement should be a major domestic building contract, not a one-page estimate.

How do I check a granny flat builder registration?

Ask for the exact business name and registration number, then check it on the Building and Plumbing Commission practitioner register before paying money. For a full second dwelling, look for a domestic builder registration class that matches the work, not only a trade licence for one part of the job.

What exclusions cause the biggest variations?

The common variation traps are sewer depth, switchboard upgrades, stormwater detention, soil-class changes, retaining walls, demolition, tree removal and council-requested changes. Any one of those can add $5,000 to $30,000, so they need a clear allowance before contract.

Is the cheapest granny flat quote ever the right one?

Sometimes, but only when the scope is genuinely smaller or simpler. If all 3 builders are pricing a 60 m2 two-bedroom dwelling and one quote is $40,000 lower, assume something important is missing until the builder proves otherwise in writing.

A fair Frankston granny flat quote must show permits, site costs, exclusions and the 5 percent deposit cap