Why Melbourne Homeowners Are Suddenly Talking About Granny Flats Again

For years, building a self-contained second home on your own block in Melbourne meant months of planning permit applications, council back-and-forth, and consultant fees before a single brick was laid. That’s changed. Victoria’s planning reforms have quietly become one of the biggest shifts in local home renovation in the past decade, and homeowners across Brighton, Toorak, Mentone and greater Melbourne are taking notice.

If you’ve got an ageing parent who needs their own space, an adult child who isn’t quite ready to leave home, or simply a block that’s bigger than you need, this is worth understanding properly before you start sketching floor plans.

What Actually Changed

Under Victoria’s planning reforms, a small second dwelling — commonly called a granny flat, secondary dwelling, or accessory dwelling unit — no longer needs a planning permit in most cases, provided it’s 60 square metres or less and sits on a lot without flooding, heritage, bushfire or other special overlays. This applies whether the second dwelling is timber-framed, modular, or built using more permanent construction methods.

That doesn’t mean it’s a free-for-all. A building permit is still required, and the structure has to meet the same safety, siting and design standards as any other home. It also can’t be subdivided or sold off separately from the main house — it stays legally tied to your existing title, which keeps things simple from a compliance standpoint but means it’s not a pathway to splitting your block into two saleable properties.

There are a few boxes that still need ticking:

• Your lot needs to be free of significant overlays (heritage, flood, bushfire, and similar).
• Standard setback, height, and fire-separation rules still apply between the two dwellings.
• The new build needs its own connections for power, water and stormwater, and in most cases a separate electricity meter.
• It has to meet current National Construction Code energy standards, including 7-Star NatHERS ratings and livable housing design features like a step-free entry.

The upshot: for a huge number of standard residential blocks across bayside and inner Melbourne, the process just got significantly faster and cheaper — but only if the project is planned properly from the start.

Why This Matters More in Melbourne Than Almost Anywhere Else

Melbourne’s rental vacancy rate has stayed tight for years, and that pressure hasn’t eased much through 2026. For homeowners with the land to spare, a compliant secondary dwelling isn’t just a lifestyle upgrade — it’s a genuine answer to some very current problems: ageing parents who want independence but not distance, adult children saving for their own place, or simply the extra rental income a well-built unit can generate.

In suburbs like Brighton and Toorak, where blocks are often generous but existing homes are heritage-sensitive or heavily built out, a secondary dwelling can also be a smarter move than a large-scale extension. It sidesteps the complexity of tying new structural work into an older home while still adding genuine, self-contained living space.

Where This Overlaps With Renovation, Not Just New Building

Here’s what a lot of homeowners miss: the granny flat conversation rarely stays separate from the rest of the house. Once you’re adding a second dwelling, most people also end up reassessing the main home — updating a tired kitchen that’s about to see more use from extended family, refreshing a bathroom before parents move closer, or rethinking the overall flow of the property with a broader home renovation.

This is exactly the kind of project where a builder who can manage both the secondary dwelling and the main home renovation earns their keep. Coordinating trades once, running one set of council conversations, and keeping design language consistent across both structures saves money and headaches compared to running two separate projects with two separate builders.

A Case in Point: Mentone

We saw this play out clearly on a recent project in Mentone, where a family’s brief started as “we need more space for my mother-in-law” and evolved into a full property rethink — a self-contained second dwelling at the rear of the block, paired with updates to the main home’s living areas. The result wasn’t just a granny flat bolted onto a backyard; it was a property that functions as two comfortable, connected homes on one title, with shared outdoor space that ties the whole thing together.

Projects like this reinforce something we see constantly: the reforms have made the paperwork faster, but they haven’t made good design any less important. A 60-square-metre dwelling still needs to feel spacious, private, and genuinely livable — not like an afterthought at the back of the yard.

What to Check Before You Start

Before getting attached to a floor plan, it’s worth working through a short list:

1. Confirm your lot’s overlays. A quick check through your council’s planning maps will tell you whether heritage, flood, or bushfire controls apply — this determines whether you’re in the no-permit pathway at all.
2. Check minimum lot size and setback requirements. Most councils expect the primary lot to be a reasonable size before a second dwelling is viable, plus clear separation distances from boundaries and the main house.
3. Budget for the building permit and NCC compliance, even though you’re skipping the planning permit stage — this isn’t a cost-free process, just a faster one.
4. Think about services early. Separate metering, stormwater connections and sewer capacity all need to be planned before design, not bolted on afterwards.
5. Work with a registered builder. With councils increasingly spot-checking compliance under the new rules, cutting corners on registration or building permits is a fast way to end up with an expensive problem.

Getting It Right From the Start

Victoria’s reforms have made secondary dwellings genuinely achievable for a lot more Melbourne homeowners than could justify the process a few years ago. But “easier to approve” isn’t the same as “simple to build well.” The blocks that benefit most are the ones where the second dwelling and the existing home are planned together — not as two disconnected projects competing for the same backyard.

If you’re weighing up a secondary dwelling, a broader renovation, or both at once, it’s worth talking it through with a licensed local builder before you commit to a design. 5J Building Group holds Domestic Builder Unlimited registration (CDB-U 73492) and has spent 15 years delivering renovation and building projects across Brighton, Toorak, Mentone and the wider Melbourne area.

Get in touch to talk through what’s possible on your block.