Under the small second dwelling rules in Victoria, you can build a self-contained home of 60 m² or less on the same lot as an existing house without a planning permit in most residential and rural zones. A building permit is always required, and a planning permit is still needed if the lot is under 300 m² in a residential zone, or where flooding, environmental or other special planning controls apply. These rules have applied since planning scheme Amendment VC253 was gazetted on 14 December 2023.
The reforms made granny flats much easier to approve, but not approval-free. This 2026 guide explains what qualifies, where the planning exemption applies, what your building surveyor checks, and the mistakes that cause delays and extra cost.
What counts as a small second dwelling?
The Victorian Government now calls these “small second homes”, while the building regulations use “small second dwelling”. To qualify, the dwelling must:
- have a total floor area of 60 m² or less, measured to the outside of external walls (or the centre of party walls) and including all roofed areas;
- be on the same lot as an existing dwelling, with only one small second dwelling per lot;
- be self-contained, with a kitchen, bathroom, toilet and laundry facilities;
- not be connected to reticulated natural gas; and
- not be subdivided or sold separately from the main home.
It can be attached to the house, detached, or created by converting an existing building. No car parking space is required, and anyone can live in it, including family, a dependent person or unrelated tenants.
Small second dwelling rules in Victoria: when is a planning permit needed?
It depends on your zone and any overlays. Planning Victoria’s applicant’s guide summarises the zone rules:
| Zone | Planning permit needed? |
|---|---|
| General Residential, Neighbourhood Residential, Residential Growth, Mixed Use and Township zones | No, unless the lot is less than 300 m² |
| Low Density Residential Zone | No |
| Rural Living, Farming and Rural Activity zones | No, unless a permit is needed for earthworks or the dwelling is closer than a setback specified in the zone; the zone’s access, sewerage, water and electricity requirements must also be met |
| Green Wedge, Green Wedge A and Rural Conservation zones | Yes |
On residential lots under 300 m², the application is assessed under Clause 54 of the planning scheme, which Amendment VC282 updated in September 2025. Overlays can also bring a permit back into play. Flooding controls such as a Special Building Overlay or Land Subject to Inundation Overlay, environmental overlays and other special controls may require one, and in a Bushfire Management Overlay, check with council early because a planning permit is commonly needed as well as the building permit.
Under the December 2023 rules, a Heritage, Neighbourhood Character or Design and Development Overlay doesn’t trigger a permit if the building is no more than 5 metres high and finished in muted tones and colours. Some applications that do need a permit can use the 10-day VicSmart process.
Planning isn’t the only hurdle. Check your title for restrictive covenants, section 173 agreements and easements, which can limit or prevent a second dwelling regardless of the exemption. A planning property report from VicPlan shows your zone and overlays, and Planning Victoria’s small second homes page has the official summary. Our explainer on the difference between a building permit and a planning permit may also help.
Why do you still need a building permit?
A small second dwelling is a new home, so it must be safe, healthy and properly sited. Your building surveyor assesses the design against the siting rules in Part 5 of the Building Regulations 2018 and the National Construction Code (NCC), issues the permit, carries out the mandatory inspections and issues the final approval, which for a new dwelling is typically an occupancy permit.
Three siting regulations were added specifically for small second dwellings:
- Regulation 74A: it must be set behind the front wall of the existing house facing the street.
- Regulation 86A: it must be provided with private open space.
- Regulation 86B: there must be a clear and unobstructed path from the front street to it.
The standard siting rules also apply, including height, setbacks, site coverage, permeability, walls on boundaries, daylight, overshadowing and overlooking. If a design doesn’t meet one of these, you may be able to seek report and consent from council to vary it, with council guided by the Minister’s Guideline MG-12. Approval isn’t guaranteed. The Building and Plumbing Commission (BPC) covers the building rules in more detail on its small second dwelling page.
NCC, energy and bushfire requirements
- Energy efficiency: since 1 May 2024, new homes in Victoria must meet the updated 7-star energy efficiency standards, including a whole-of-home energy budget covering fixed appliances such as heating, cooling, hot water and lighting.
- All-electric by design: with no gas connection allowed, heating, hot water and cooking need to be electric, so choose efficient appliances early.
- Bushfire: in a designated bushfire prone area, a Bushfire Attack Level (BAL) assessment under AS 3959 is required for the building permit, and new homes must be built to at least BAL-12.5. A higher BAL usually means more expensive windows, cladding and decking.
- Fire separation: if the dwelling is attached to the house, or close to it or a boundary, the NCC’s fire-separation provisions can require fire-rated walls and limit openings.
- Conversions: turning a garage, shed or studio into a dwelling changes its classification, so it generally has to be upgraded to meet the requirements for a home, including energy efficiency, wet areas, weatherproofing and fire safety.
Connecting water, sewer and power
A small second dwelling can share the existing home’s services, but capacity can be the sticking point. Before finalising the design, check:
- with your water corporation, where the sewer connection point is and whether you’ll need a pump;
- with your electrician or electricity distributor, whether the existing supply can handle an extra all-electric home;
- where stormwater from the new roof will discharge; and
- whether you want separate metering, which affects how you bill a tenant.
What drives the cost of a small second dwelling?
Costs vary widely, so treat any “from” price with caution. The main cost drivers are usually:
- site conditions such as soil, slope and trees, which shape the footing design;
- access for machinery or, for a prefabricated unit, crane and delivery access;
- service connections and upgrades;
- BAL construction and any fire-rated walls;
- whether a planning permit or report and consent is needed;
- consultant reports, such as soil testing, engineering, energy rating and BAL assessment; and
- the level of finish.
Building permit fees and the building permit levy are part of the budget too.
Common mistakes to avoid
- Measuring only the internal area. The 60 m² limit is measured to the outside of the walls and includes all roofed areas, so a covered deck or verandah can push you over.
- Putting it in front of the house. Regulation 74A requires it to sit behind the front wall of the existing dwelling unless council consents.
- Forgetting the path. A clear path from the street is required, which can clash with side fences, gates or driveways.
- Planning a gas connection. It isn’t allowed.
- Missing a covenant or overlay. A title and planning check at the start avoids a redesign later.
- Assuming it can be sold off later. It can’t be subdivided from the main home.
- Starting before the building permit is issued. Unpermitted work is costly to fix.
Can an owner-builder build a small second dwelling?
Yes. The owner-builder rules include exemptions for small second dwellings: you don’t have to live in it, and the limit of one owner-builder permit every five years for a different property doesn’t apply. You’ll still need a certificate of consent from the BPC if the work is worth more than $20,000. Our guide to being an owner-builder in Victoria explains the process.
How JLN can help
Our building surveyors issue building permits for small second dwellings across Melbourne and regional Victoria. We check siting, NCC and energy requirements early, tell you which reports you need, and carry out the mandatory inspections through to final approval.
Frequently asked questions
Can I rent out a small second dwelling in Victoria?
Yes. Anyone can live in or rent a small second dwelling, including family members and unrelated tenants. Residential tenancy laws apply, so the usual renting rules must be followed.
Can I subdivide the small second dwelling later?
No. A small second dwelling can’t be subdivided or sold separately from the main home. Creating two separately titled dwellings is a different pathway that involves planning approval for the subdivision.
My block is under 300 m². Can I still build one?
Possibly, but in a residential zone you’ll need a planning permit, assessed under Clause 54 of the planning scheme. A building permit is still required as well.
Can a tiny home or prefab unit be a small second dwelling?
Yes, if it meets the same planning and building requirements, including the 60 m² limit, the siting rules, the NCC and a building permit. Prefabricated units still need footings, service connections and inspections, so sort out siting and approvals before you order one.
Can a small second dwelling be attached to my house?
Yes. It can be attached, detached or created by converting part of an existing building, as long as it is self-contained and within the 60 m² limit. An attached design needs careful planning for fire separation, sound and access, so talk to your building surveyor at concept stage.
This article is general information current as of September 2026, not legal advice. Every project is different – ask us to confirm what applies to yours.
Planning a granny flat? Call our building surveyors on 0422 234 951 or send your plans for a building permit quote and we’ll give you fast, practical advice on what your site allows.