In Melbourne’s competitive property market, more and more landowners are exploring ways to generate rental income or create practical living spaces for extended family. Among the most effective and increasingly popular solutions are granny flats, the future of multi-generational living. These small, self-contained dwellings offer excellent potential for return on investment and lifestyle flexibility, but the reality is, not every block is suitable for a granny flat.
If you’re planning to build a granny flat in Werribee or any other part of Victoria, it’s not just about design ideas or how the flat will look. Your land needs to meet a range of physical, legal, and strategic criteria. That’s why the first and most important step is understanding site feasibility.
This blog breaks down what makes a block eligible, covering essentials like lot size, zoning, slope, access, overlays, and more, so you can plan with confidence and avoid costly surprises.
Why Site Feasibility Is The Foundation Of Every Successful Build
Before discussing floor plans or choosing finishes, the first thing you need to ask is whether your block can legally and practically support a second dwelling. A feasibility report is your roadmap; it determines if the project is possible from both a planning and financial standpoint.
Why It Matters
Skipping this step often leads to major delays, surprise costs, or rejected council permits. For landowners in growing areas such as Werribee, Point Cook, or Melton, where block configurations and zoning can vary significantly, a professional feasibility assessment can protect you from wasting tens of thousands of dollars.
A complete feasibility review covers:
- Minimum lot size and dimensions
- Boundary setbacks and site coverage
- Easements, slope, and drainage
- Zoning regulations and overlays
- Access points for tenants and construction
- Potential for dual occupancy
This is where Innovista Group comes in. Our experienced team works with Melbourne landowners and developers to deliver detailed site assessments that consider every variable, ensuring that your proposed granny flat meets both council regulations and your personal goals.
1. Minimum Lot Size And Site Coverage
The first hurdle is size. Most councils in Victoria require a minimum lot size of 450m² for a detached granny flat. But it’s not just total size, it’s also about how much of your land is already occupied.
Let’s say your lot is 600m² and your main house occupies 250m². If your local council enforces a 50% site coverage limit, you’ll only be allowed to build on 300m² total. That means you’ve got just 50m² left for your granny flat, not much space if you’re aiming for a larger floorplan.
Other planning requirements often include:
- Maintaining 30% open space
- Minimum private outdoor space per dwelling
- Distance between the new and existing structures
This is why a custom site evaluation is so valuable. Local guidelines may be strict, but every block has unique limitations, and general rules rarely tell the full story
2. Setbacks, Boundaries, And Easements
Even if your block is large enough, setbacks and easements can eat into your usable land. Setbacks are buffer zones from fences, dwellings, or other property boundaries that limit where you can build.
In Melbourne, typical requirements include:
- 1 to 1.5 metres from side boundaries (based on height)
- 3 metres from the ear boundaries
- Additional clearance from neighbouring habitable room windows
On top of this, many properties have easements, designated strips that carry sewer or stormwater pipes and cannot be built over. Some easements reduce the usable space by up to 20%, significantly impacting the potential layout and orientation of your granny flat.
Our team at Innovista Group provides feasibility assessments that map these factors with precision. You’ll know upfront what portion of your land is genuinely available for development.
3. Access And Entry Requirements
Access isn’t just for your future tenant; it’s a crucial part of getting your granny flat approved. Most Melbourne councils require a clear, unobstructed path of at least 1.2 metres from the street to the proposed dwelling. This ensures emergency services can access the flat and that utility services like water, power, and gas can be connected.
If your home is in a tight suburb like Werribee, meeting this requirement might mean removing fences, widening paths, or relocating utilities. On the other hand, corner lots or properties with rear laneways often have a distinct advantage when it comes to access.
If your block lacks sufficient access, approval may be delayed or denied, or you may face costly redesigns mid-project.
4. Zoning And Local Planning Controls
Every property in Victoria is governed by a zoning designation. These zones affect whether you can build a second dwelling and what regulations you must follow.
Here’s a quick snapshot:
- GRZ (General Residential Zone): Usually allows granny flats
- NRZ (Neighbourhood Residential Zone): May impose tighter development controls
- RGZ (Residential Growth Zone): Supports higher density but involves stricter application processes
- Rural and Farming Zones: Require greater infrastructure and longer approval times
Overlay restrictions like heritage, bushfire, or flood overlays can also impact what and how you can build. A bushfire overlay, for example, might require you to use special flame-resistant materials or increase your setbacks, both of which raise your granny flat cost significantly.
This is where having the right guidance from dual occupancy property developers Melbourne residents trust becomes essential. Understanding and navigating local codes is not something you want to leave to chance.
5. Slope, Drainage, And Soil Conditions
The ground beneath your feet matters more than most people realise. Some of Melbourne’s outer suburbs, like Werribee and Sunbury, are known for having reactive clay soils or uneven ground that requires additional engineering, making From Soil Test to Slab: Behind the Scenes of a Granny Flat an essential part of understanding how early groundwork impacts both design and cost.
Our feasibility process includes:
- Slope analysis (if more than 3–5%, you may need a split-level design)
- Soil classification testing
- Drainage planning for proper water runoff management
Sloped or poorly drained land may require reinforced footings, drainage channels, or retaining walls, which can all increase your overall granny flat cost. Knowing this upfront helps you avoid expensive changes during construction.
6. Existing Structures And Tree Constraints
Before building, it’s important to consider what already exists on your land. Old garages, pergolas, or sheds may need to be removed. Even more importantly, trees can stop your project before it starts.
Melbourne councils often have strict regulations about removing trees, particularly large or native species. You may need a permit, and in some cases, you’ll be required to plant replacements elsewhere on the property.
A comprehensive site feasibility report, like the ones Innovista Group provides, will include a map of all existing structures and vegetation to help you plan smartly from day one.
What Innovista Group Offers
At Innovista Group, we’ve worked with hundreds of clients, both homeowners and developers, to assess the feasibility of building a second dwelling. Our detailed reports include:
- Council overlays and zoning guidance
- Full site measurements and slope analysis
- Infrastructure and access evaluations
- Legal and compliance checks for dual occupancy
- A clear picture of the potential build size and investment value
We not only tell you what’s possible, we help you make informed decisions about next steps. If you’re thinking of building in Werribee or surrounding suburbs, our team is ready to assist with full support from the first consultation through to construction.
Final Thoughts: Know Before You Draw
Building a granny flat can be a game-changer for property owners, whether your goal is rental yield, multigenerational housing, or future flexibility. But not every block is suitable, and assumptions can cost you dearly.
That’s why it’s so important to conduct a professional site feasibility assessment before you start engaging architects or submitting planning applications. From zoning to access, slope to overlays, getting expert advice early ensures your project is legally compliant, financially viable, and technically possible.
Whether you’re an investor or a long-term homeowner, don’t move forward blind. Let Innovista Group, the trusted dual occupancy property developers for Melbourne homeowners, help you unlock the full potential of your land.
Ready to get started on your granny flat project? Contact us for a personalised consultation.
