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How to build a modular home, step by step

From Modular Living Australia — the independent knowledge base Last updated: 8 Oct 2026

Building a modular home follows the same broad path as any new house — land, money, builder, contract, approval, construction, handover — but the order of decisions matters more, because much of the house is built in a factory before anything happens on your block. Mistakes made in the first three stages are usually the expensive ones.

This page sets out the sequence as ten stages. Each stage has a short checklist and links to the guide on this site that covers it in depth. It does not repeat those guides; it tells you when to read them.

The ten stages at a glance §

Stage 1: Choose the housing type §

Decide what you are actually building before you talk to anyone selling it. A modular home, a panelised or kit home, a transportable home and a conventional build each come with different approvals, finance and contracts. If the dwelling is a second home behind an existing house, the rules for a granny flat apply instead.

Checklist:

• Is this a main residence, a second dwelling, or a home that may need to move later?
• Have you compared modular with the alternatives on cost and timeline? See modular vs traditional, modular vs kit home and knockdown rebuild vs modular.
• If unsure, run the housing type selector.

Stage 2: Check the land §

Site facts decide which approval pathway is available, what the foundations will cost and whether a truck and crane can reach the block. Establish them before you choose a design.

Checklist:

• Zoning and minimum lot size, from your state rules page: modular home rules by state.
• Bushfire, flood and heritage overlays. See bushfire attack levels and flood-prone land.
• Soil classification and slope: site classification and soil reactivity.
• Sewers and easements running through the block: building over sewers and easements.
• Wind or cyclone region: wind regions and cyclone regions.
• Rural land: building on rural land.
• Access for a transport vehicle and crane, including overhead power lines and tight corners.

Stage 3: Build the budget §

A builder's headline price usually describes the house, not the finished project. Builder-published guidance notes that transport and installation are sometimes included only within a set radius of the factory, so a block outside that radius pays more for the same house.^[3]

Checklist:

• Base price for the design, from published price lists: modular home costs by state. These are commercial figures.
• Site works, foundations and retaining: site works costs.
• Transport, crane and installation.
• Service connections, or off-grid systems: service connections.
• Approval fees and council contributions: DA fees and developer contributions.
• Stamp duty on the land: stamp duty on modular homes.
• A contingency for site surprises. Work through the hidden cost checklist.

Stage 4: Line up finance §

Get finance approved in principle before you sign with a builder, because the lender's rules can decide which builders are practical. A factory build creates much of its value before anything appears on your land, and that is where lending arrangements differ.

Checklist:

• Ask the lender how it releases funds for work done in a factory: can you get a mortgage on a modular home.
• Check lender-specific programs: CommBank assessed manufacturers and Keystart in WA.
• Check grants and schemes: First Home Owner Grant, 5% deposit scheme and Help to Buy.
• Get the builder's payment schedule to the lender before formal approval.

Stage 5: Shortlist and check builders §

Ask at least three builders to quote against the same scope, then check each one on the public registers. In NSW the licence search runs by name, licence number or ABN.^[4] The NSW register also lets you check Home Building Compensation certificates, which are required for residential building work over A$20,000.^[5]

A NSW licence held by an individual does not let that person's company sign the contract; the company must hold its own licence.^[1] Check that the name on the licence matches the name on the contract.

Checklist:

• Licence number, class and status on the state register.
• The legal entity name and ABN, matching the contract.
• Which party will be named on the building permit, and whether their contract covers compliance of the finished building or only installation: licence and insurance checks.
• Itemised quotes on an identical scope: choosing a prefab builder.
• The builder directory lists companies by state. Inclusion is not an endorsement and entries have not been independently verified.

Stage 6: Sign the contract §

In NSW, building work over A$5,000 including GST needs a written contract, and work over A$20,000 needs a large job contract with a progress payment schedule and a five clear business day cooling-off period.^[1] The deposit cannot exceed 10 percent, and where Home Building Compensation cover is required the builder cannot ask for a deposit until the cover is in place and you have the certificate.^[1]

Checklist:

• Inclusions and exclusions written down, with "turnkey" defined: what turnkey includes.
• Deposit within the legal cap, and paid only after you have checked the insurance certificate.
• Progress payments tied to work done, not time on the job.^[1]
• How site-condition variations are priced.
• The physical milestone that counts as completion.
• A solicitor's review before you sign. See also the prefabAUS standard form contract.

Stage 7: Get approval §

Being built in a factory does not exempt a home from approval. Builder-published guidance reports that in most states a modular home is treated as a permanent Class 1a dwelling needing full approval.^[6] In NSW, a proposal that meets the complying development standards can be approved in as little as 20 days, against an average of 70 days for a development application.^[2]

Checklist:

• Confirm the pathway your site allows: approval process.
• Read your state page: modular home rules by state.
• Energy rating: the 7-star NatHERS rule.
• Accessibility requirements: Livable Housing Design Standard.
• Agree in writing who lodges each application.
• Do not lock in a factory slot or delivery date until the pathway is confirmed.

Stage 8: Factory build and site works §

The house is built in the factory while foundations and services go in on site. This is the stage where most of your money is paid and the least is visible to you.

Checklist:

• Each progress claim matches a completed stage: progress payments for off-site construction. Track it in the payment timeline tool.
• Ask for a factory inspection, or dated photos, before wall linings close up.
• Confirm who insures the modules in the factory and in transit: the insurance gap.
• Know what happens to paid-for modules if the builder fails: if your builder becomes insolvent.

Stage 9: Delivery and installation §

Delivery day puts a lot of risk into a few hours. Builder-published guidance puts crane hire at roughly A$260 to A$1,530 per hour, usually with a four to ten hour minimum.^[3]

Checklist:

• Crane position, hire hours and rate agreed: delivery, transport and craneage.
• A condition check at dispatch and on arrival, before modules are joined.
• Who pays if the lift cannot go ahead on the day.
• Service connections booked: service connections.

Stage 10: Handover §

In NSW, statutory warranties run for six years for major defects and two years for other defects, starting from completion.^[1] Where the contract does not define completion, NSW law takes the earliest of handover, the builder's last work on the job or the issue of an occupation certificate.^[1]

Checklist:

• An independent inspection before final payment: handover inspections.
• Module joins, the foundation connection and services split across modules checked.
• Occupation certificate issued before you move in.
• Warranty documents and maintenance obligations: warranties and maintenance.
• If a dispute arises: building disputes by state.

Related step-by-step guides §

• How to build a granny flat, step by step
• How to get a tiny home, step by step
• How to buy a transportable home, step by step

What is not covered here §

Contract thresholds, deposit caps, cooling-off periods and warranty periods for states other than New South Wales are not covered by the sources compiled here. Each state sets its own; check your state's building regulator. Approval timeframes outside NSW are not covered here either.

This page does not estimate a total project cost or a total timeline. Both depend on the site, the design and the approval pathway, and the figures on the linked cost pages are builder-published commercial guidance. Owner-builder projects follow a different path; see owner-builder permits by state.

References §