Planning & Permits

Do I Need a Building Permit?

The short answer for almost every habitable cottage — and the rare exceptions where you might not.

Reading time

9 min read

Last reviewed

August 2026

Applies to

VIC · NSW · QLD · SA · TAS · WA · NT · ACT

Covers

Permit requirements · Exemptions · Transportable cottages · Retrospective approval · Penalties

The almost-always-yes answer

If the structure is a habitable dwelling — somewhere people live or sleep — you almost certainly need a building permit. This includes expandable cottages, transportable homes, granny flats, cabins and tiny homes used as dwellings. The fact that the cottage is built in a factory and transported to site does not exempt it from the building permit requirement. A building permit must be issued before the cottage is installed and occupied. This is not a grey area — it's the law in every Australian state and territory.

The narrow exemptions

Exemptions are limited and vary by state. They typically include very small non-habitable structures (a garden shed under a certain floor area, often around 10m²), some minor repairs and maintenance, and certain farm buildings. A habitable cottage — even a small one — does not fall within these exemptions. If you're unsure whether an exemption applies, check with your local council or a building surveyor before proceeding. Assuming an exemption that doesn't exist leads to the same penalties as building without a permit.

Why 'transportable' doesn't mean 'permit-free'

Some people assume a transportable cottage doesn't need a permit because it arrives on a truck and sits on the ground. This is incorrect. Once a dwelling is placed on a property and used for habitation, it requires a building permit regardless of how it was built or how it's fixed. The building surveyor needs to confirm the structure meets the NCC for the site — wind rating, BAL, foundations, energy, plumbing and electrical. 'Transportable' describes the construction method, not the regulatory status. The truck doesn't change the law.

Tiny homes on trailers: the grey area

This is a common grey area. A tiny home on a registered trailer that's used as a vehicle (moved regularly, registered, used for temporary accommodation) may be treated differently. But the moment it's parked on a property and used as a permanent dwelling, the building permit requirement typically applies. Each state handles this slightly differently, and councils are increasingly scrutinising tiny homes used as permanent dwellings. If you intend to live in it permanently, get advice from a building surveyor before committing — don't assume the trailer exempts you.

Building without a permit: the real consequences

Building without a required permit can lead to: stop-work orders, fines (which can run into thousands or tens of thousands of dollars), orders to remove the unapproved structure, difficulty selling the property, and insurance that won't pay out on unapproved works. If you've already installed a cottage without a permit, a building surveyor may be able to issue a retrospective certificate of compliance — but this is more expensive and complex than doing it right the first time, and it may not be possible if the structure doesn't meet current standards. The penalties are real and they escalate.

How to get a definitive answer

The most reliable way is to speak with a registered building surveyor early in your project. They can tell you whether a permit is required, what documentation you'll need, and an indicative timeline and cost. You can also check your state's building authority website for exemption lists. Don't rely on a supplier telling you 'no permit needed' — the requirement is determined by the building surveyor and your state's legislation, not by the manufacturer. A supplier who tells you to skip the permit is exposing you to legal and financial risk.

Do You Need a Building Permit?

A simple decision path for a habitable structure.

Is the structure habitable?
Yes → Building permit required
Check for planning permit too
Engage a building surveyor
Prepare documentation
Permit issued before installation

In practice

A cottage arriving on site — it needs a building permit before installation, just like a site-built home.
A cottage arriving on site — it needs a building permit before installation, just like a site-built home.
Once installed on compliant foundations and permitted, it's a lawful permanent dwelling.
Once installed on compliant foundations and permitted, it's a lawful permanent dwelling.

From our experience

From our experience, the customers who ask 'do I need a permit?' and then act on the answer — rather than hoping it doesn't apply — have the least stressful projects. The permit process is there to protect you: it confirms your cottage is safe, compliant, and insurable.

We've had conversations where a customer was told by another supplier that no permit was needed. In every case, the building surveyor confirmed a permit was required. Skipping the permit is a false economy that catches up with most people eventually — often at the worst time, when they try to sell or insure.

Common Mistakes to Avoid

  1. 1

    Assuming a transportable cottage doesn't need a permit because it arrives on a truck.

  2. 2

    Treating a tiny home on a trailer as exempt when it's used as a permanent dwelling.

  3. 3

    Relying on a supplier who says 'no permit needed' — the building surveyor decides, not the supplier.

  4. 4

    Assuming a small cottage is exempt because it's small — habitable dwellings need permits regardless of size.

  5. 5

    Installing the cottage first and trying to get a permit afterwards — retrospective approval is harder and costlier.

  6. 6

    Not checking whether a council planning permit is also needed (in addition to the building permit).

  7. 7

    Assuming 'I'm on rural land so the rules don't apply' — rural land has the same building permit requirement.

What changes between states?

Requirements vary by jurisdiction — always confirm with your local authority.

StateNotes
VictoriaThe Building Act 1993 and Building Regulations 2018 set out exemptions. The VBA publishes the full exemption list.
NSWExemptions are in the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008.
QueenslandThe Building Act 1975 and the Building Regulation 2021 define exempt building work.
Other statesEach state publishes its own exemption schedule — check your state building authority's website before assuming any exemption applies.

When this guide doesn't apply

This guide may not apply if:

  • You're erecting a small non-habitable structure (e.g., a garden shed under the exempt floor area) — but check your state's exemption schedule.
  • You're doing minor maintenance or repairs that fall within your state's exempt works list.
  • You're building outside Australia — this guide reflects Australian state and national frameworks.

Frequently Asked Questions

Does a tiny home on a trailer need a building permit?

It depends on classification. If it's used as a permanent dwelling on a property, a permit is likely required. If it's a registered vehicle used for temporary accommodation, different rules apply — but using it as a permanent dwelling usually still triggers building requirements. Check with a building surveyor for your situation.

Can I put a cottage on my land without a permit 'just to try it'?

No. Placing and using a habitable dwelling without a permit is unapproved building work, even temporarily. The penalties and risks are the same as for permanent construction.

What if my supplier says no permit is needed?

Treat that with caution. The permit requirement is determined by the building surveyor and your state's building law, not the supplier. A reputable supplier will help you obtain the permit, not tell you to skip it.

Can I get a permit after I've already installed the cottage?

Sometimes, via a retrospective compliance certificate — but it's more expensive, more complex, and may not be possible if the structure doesn't meet current standards. It's always cheaper to get the permit first.

Does rural land have different rules?

The building permit requirement is the same on rural land. Rural land may have additional planning requirements (dwelling entitlements, wastewater) but the building permit requirement for a habitable dwelling is universal.

Authoritative sources & further reading

Victorian Building Authority — when a permit is requiredNSW Fair Trading — building approvalsQBCC — when a building approval is neededAustralian Building Codes Board

Do I Need a Building Permit? Decision Guide

A simple flowchart and checklist that takes you from your structure type and intended use to a clear answer on whether you need a building permit — with the exemption criteria for each state and the questions to ask a building surveyor to confirm.

This page provides general information about the pathway commonly followed in Victoria. Requirements vary by property, local government area, building classification and proposed use. Obtain site-specific advice before making financial commitments.

Connected topics

Helpful tools

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The Crown

Reviewed by

Homes & Domes Victoria Technical Team

Last technical review

August 2026

Sources updated

August 2026

All Learning Centre guides

Last reviewed: July 2026 · Applicable jurisdiction: Victoria · General information only — not legal, planning or engineering advice.

Requirements vary by property, local government area, building classification and proposed use. Obtain site-specific advice before making financial commitments.