Step-by-Step Guide to Installing Small Granny Flats in VIC, NSW, QLD, and SA

As more Australians seek flexibility in their living arrangements, granny flats have become a popular choice for homeowners. Whether you're looking to accommodate family, create a rental opportunity, or simply add value to your property, installing a small granny flat is an excellent option. Building a granny flat (also known as a small second home, secondary dwelling, or ancillary accommodation) is an increasingly popular way to add living space, support family, or generate rental income in Australia. Rules vary significantly by state, with recent reforms in VIC, NSW, QLD, and SA making the process easier in many cases—often allowing rentals to anyone and streamlining approvals.

This guide outlines the current step-by-step process for installing a small granny flat in Victoria (VIC), New South Wales (NSW), Queensland (QLD), and South Australia (SA) as of early 2026. Always verify the latest details with your local council, a private certifier, or official state planning portals, as minor local variations or updates can apply.

Victoria (VIC)

Victoria's rules (updated via amendments like VC253, VC259, VC266, and VC282) make small second homes up to 60m² straightforward in most residential/rural zones. No planning permit is usually needed if compliant; a building permit is always required. New builds must meet 7-star NatHERS energy efficiency, livable housing standards (e.g., accessible features), and no gas connections. In Victoria, small second homes (often called granny flats) up to 60 square meters generally do not require a planning permit if they meet certain criteria, such as being on residential or rural zoned land without special overlays like flooding or heritage restrictions. However, a building permit is always required to ensure compliance with safety and design standards.

Here's a step-by-step process:

1. Check eligibility and site — Verify zoning, no overlays (flood/bushfire/heritage), and site access for delivery/crane.
2. Select modular design/builder — Choose from prefab providers (e.g., standard or custom plans ≤60m²). Get quotes including factory build, BASIX/NatHERS compliance, and transport. If not, speak to us and we are happy to recommend overseas manufacturers who have successfully built in Australia. We have extensive experience in working with manufacturers in Turkey, Japan, Korea and China.
3. Site assessment and prep — Engage a building surveyor checks access, assess boundaries, setbacks, underground services, connectivity to your utilities and site suitability.
4. Design the dwelling — Engage a designer/architect or speak to our inhose designer and archietcts to document site plans, elevations, sections (≤60m², self-contained, meets NCC, energy/livable standards).
5. Commence a soil geotechnical investigation report - Find out what soil, footings needs to be, what is the allowable bearing capacity, where is the groundwater etc
6. Obtain building permit — Submit plans to registered building surveyor/private certifier or council. Modular designs often fast-track; no planning permit usually required.
7. Factory construction — Unit built off-site (2–8 weeks typical), including fit-out (kitchen, bathroom, wiring).
8. Delivery and installation — Footing constructions based on geotechnical report provided. Modular home transport to site, crane lift into place, tied down to foundations, connect services—often completed in 1 day.
9. Final inspections and occupancy — Certifier inspects; issue occupancy permit. Ready to live in or rent immediately. Rental to anyone is allowed, with strong investment potential.

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New South Wales (NSW)

In NSW, granny flats (secondary dwellings) can often be approved via a fast-track Complying Development Certificate (CDC) or Development Application (DA) standard application.

Here's a step-by-step process:

1. Assess property eligibility: Confirm your lot size, zoned residential, and free from restrictions like heritage, flood, or bushfire zones. Obtain a Section 10.7 Planning Certificate from your council to identify risks.
2. Site assessment and prep — Engage a building surveyor checks access, assess boundaries, setbacks, underground services, connectivity to your utilities and site suitability.
3. Commence a soil geotechnical investigation report - Find out what soil, footings needs to be, what is the allowable bearing capacity, where is the groundwater etc
4. Design the dwelling — Engage a designer/architect or speak to our inhose designer and archietcts to document site plans, elevations, sections etc together with your modular home manufacturer.
5. Engineering compliance - Engage with our engineering department to design the footings, assess the modular units, engineering reports and issue certificate of compliance. Upgrades may be required athighwind speed locations, which will be coordinated with the modular manufacturer.
6. Engage an energy assessor to assess your building for a BASIX report.
7. Factory construction — Unit built off-site (2–8 weeks typical), including fit-out (kitchen, bathroom, wiring).
8. Delivery and installation — Footing constructions based on geotechnical report provided. Modular home transport to site, crane lift into place, tied down to foundations, connect services.
9. Choose pathway:
   
   1. CDC (Complying Development Certificate) if it meets the standards (faster), applied via NSW Planning Portal (usually through a certifier)
   2. Otherwise lodge a DA (Development Application) with council
10. Secure Construction Certificate (CC) — Issued post-approval for building compliance.
11. Obtain Occupation Certificate.
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Queensland (QLD)

In Queensland, secondary dwellings (granny flats) require building approval, and development approval may be needed depending on local planning schemes. There's no statewide minimum lot size, but councils often require the property to be suitable for dual occupancy. QLD’s planning guidance is very direct: you will need building approval, and you should still confirm with council whether you need development approval first.

Here's a step-by-step process:

1. Research local zoning and regulations: Contact your local council to check zoning laws, overlays (e.g., flood-prone areas), and if development approval is required. Ensure the flat complements the main dwelling and meets setbacks. Talk to council early to confirm whether development approval is needed first.
2. Plan and design: Develop a project plan including budget and timeline. Hire a designer for plans compliant with the Queensland Development Code (QDC) and NCC. If building as an owner-builder, complete required training and apply for an owner-builder permit via QBCC (fee around $462).
3. Site assessment and prep — Engage a building surveyor checks access, assess boundaries, setbacks, underground services, connectivity to your utilities and site suitability.
4. Commence a soil geotechnical investigation report - Find out what soil, footings needs to be, what is the allowable bearing capacity, where is the groundwater etc
5. Design the dwelling — Engage a designer/architect or speak to our inhose designer and archietcts to document site plans, elevations, sections etc together with your modular home manufacturer.
6. Engineering compliance - Engage with our engineering department to design the footings, assess the modular units, engineering reports and issue certificate of compliance. Upgrades may be required athighwind speed locations, which will be coordinated with the modular manufacturer.
7. Obtain permits: Apply for building approval through a private certifier or council. If needed, get development approval first. Include site plans, engineering, and compliance details. Building approval is required for any new secondary dwelling.
8. Buid, inspections and completion: Undergo mandatory inspections (e.g., slab, frame, final). Obtain a Certificate of Occupancy from QBCC or certifier.

Recent changes allow renting to non-family, but check for fire safety upgrades if renting.

South Australia (SA)

In South Australia, ancillary dwellings (granny flats) up to 60m² can be built on properties of at least 600m², with recent rule changes allowing rental to anyone. Applications go through the SA Planning Portal. For all ancillary accommodation, development approval is generally required and lodged via PlanSA.

Here's a step-by-step process:

1. Check eligibility and regulations: Ensure your property is max 60m² with up to two rooms (one bedroom), shares services with the main house, and is set back 500mm from the front and no taller than 3m wall height. Determine if it’s treated as ancillary accommodation / granny flat under your site rules. Review local council rules for aesthetics and impacts.
2. Site assessment and prep — Engage a building surveyor checks access, assess boundaries, setbacks, underground services, connectivity to your utilities and site suitability.
3. Commence a soil geotechnical investigation report - Find out what soil, footings needs to be, what is the allowable bearing capacity, where is the groundwater etc
4. Design the dwelling — Engage a designer/architect or speak to our inhose designer and archietcts to document site plans, elevations, sections etc together with your modular home manufacturer.
5. Engineering compliance - Engage with our engineering department to design the footings, assess the modular units, engineering reports and issue certificate of compliance. Upgrades may be required athighwind speed locations, which will be coordinated with the modular manufacturer.
6. Lodge application: Submit a development application via the SA Planning Portal (online or in-person). This includes planning consent, building consent, and development approval. Fees apply, and fast-tracking may be available in master-planned areas.
7. Obtain approvals: Get building consent after planning approval. If non-compliant (e.g., setbacks), seek variations.
8. Construction phase: Hire a builder for site prep, foundations, framing, utilities, and finishing. Process takes 8-12 weeks typically.
9. Final inspections: Council or certifier inspects for compliance, issues a Certificate of Occupancy. Completion/occupancy documentation through the SA process

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How much Does it Cost?

Here’s a realistic cost picture for a China-built overseas modular home (the expandable 3-bedroom 1 bathroom unit) delivered to Australia. This is an approximate price in 2026, including typical overseas unit prices and landed-in-Australia considerations.

Base Unit Cost in China (FOB)

When sourced directly from Chinese manufacturers, the factory price of an expandable modular or container-based home with 2–3 bedrooms can be very low before shipping and compliance costs:

Commonly quoted prices (FOB China):

• Smaller expandable modular units with 2 bedrooms, Chinese standard compilant can cost US $8,700 – $16,400 per unit. These are raw modular products, not final on-site delivered homes, and not Australian Standards compilant.
• Australian Standards compliant units, for example 20ft, Wind Region N2 for a 2 bedrooms, can cost around US $17,000-21,000 per unit. Which involves a fair bit of upgrade from the raw model. Some modification, such as more windows, change of door locations etc will require some modification on the engineering design report. Local design such as footing design is still require.

These prices are factory-level quotes and do not include Australian engineering compliance, Australian freight, port fees, compliance upgrades, local installation, or site preparation.

🚢 Sea Freight & Import Costs

When you import a modular home from China to Australia, there are several key additional costs:

1. Sea Freight (China → Australia)

• Depending on container size and port, sea freight per unit for a 20-40 ft container is often in the range of AUD 1,500–5,000+. (Estimates vary by carrier, season and container size)

2. Customs & Quarantine

• Australia has strict customs, biosecurity inspections, duty and GST on imported prefabs. Brokers and clearance fees can add AUD 2,000–6,000+ depending on documentation, inspections, and fumigation requirements.

3. Local Delivery & Offload

• Transport from port to the site, cranes or lifting gear to position the modules, and local trucking costs are typically AUD 2,000–10,000+ depending on distance, size, and access constraints.

4. Compliance & Conversion

The raw modular unit may need:

• Upgrades to structural elements for wind.
• Additional truss roof for upgrade
• Balcony and staircase for Australian Standards and NCC Compliance
• Australian electrical, plumbing, fire and energy efficiency to match NCC compliance
• Full engineering report confirming materials, wind, seismic compliance to various Australian Standards
• Certification and engineering certificate of compliance.

These compliance and conversion costs can easily be AUD $4,000 – $20,000+ in professional fees and local modifications. If you purchased the Australian-compliant ready units, may only require a certificate of compliance, which only costs around AUD $1,500+GST.

Rough “Landed & Installed” Total (Indicative)

Taking the above into account, a China-built expandable 3-bedroom modular home landed in Australia and installed could cost, on a typical project (without finishes, landscaping or services):

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Depending on the type of design, specifications, the manufacturers we worked with that already has Australian Standards compliance often costs from $25,000 (1 bedroom), $70,000 (2 bedroom) and $75,000 (3 bedrooms). These costs are landed and installed cost, excluding footing construction. Figures are approximate and dependant on distance from port to site.

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