Building a townhouse behind an existing home used to be something you mostly saw in inner Melbourne suburbs. These days, it is happening right across Bayside and the south-east. We see it in Bentleigh East, Cheltenham, Hampton, Glen Iris and even quieter residential pockets where large backyards are slowly giving way to modern dual occupancy homes.
Over the years, our team at MJS Construction Group has spoken with hundreds of homeowners asking the same question: “Can I subdivide my block and build a townhouse?”
Sometimes the answer is straightforward. Other times, the site looks perfect at first glance but has a covenant, drainage issue or planning overlay sitting quietly in the background waiting to throw a spanner in the works.
The good news is this: if you approach subdivision properly from the start, there is genuine opportunity to unlock value from your land while creating a quality home that fits the area.
The First Question: Is Your Block Suitable for Subdivision?
Before anyone starts sketching townhouse designs or talking demolition, the first step is checking whether the land can actually support subdivision.
A large backyard alone does not guarantee approval. We have seen blocks over 700 square metres fail because of access restrictions, while smaller corner sites moved through council smoothly because the layout worked better.
Zoning, overlays and council rules decide what is possible
Every Melbourne council has its own planning controls. Your zoning affects density, setbacks, height limits and neighbourhood character expectations.
In many Bayside suburbs, these are the common residential zones:
| Zone Type | What It Usually Means |
| General Residential Zone (GRZ) | Often supports dual occupancy or townhouse projects |
| Residential Growth Zone (RGZ) | Encourages higher-density housing |
| Neighbourhood Residential Zone (NRZ) | More restrictive with tighter development controls |
Planning overlays also play a major role. Heritage overlays, flood overlays, vegetation protection controls and bushfire management overlays can all affect what council will approve.
One project we reviewed in Beaumaris looked ideal from the street. Big frontage. Flat land. Plenty of backyard space. Then the title search revealed a restrictive overlay tied to vegetation protection. That single issue reshaped the entire design.
That is why early planning advice matters. Better to find out before spending money on architectural drawings.
Minimum land size is only part of the answer
People often hear that you need 650 to 700 square metres for subdivision. There is some truth in that, but it is far from a hard rule.
Councils look at:
- Usable land area
- Site width
- Access requirements
- Private open space
- Parking
- Existing dwelling location
- Overlooking and overshadowing
A narrow block with poor access can become difficult very quickly.
Corner blocks, on the other hand, are often worth their weight in gold. Separate street frontages can improve access, simplify planning and boost resale appeal later.
Site Features That Can Make or Break a Townhouse Project
Once zoning and planning controls look promising, the next step is reviewing the physical characteristics of the land.
This is where experience matters. A site may look fine to the average buyer but raise red flags immediately for a builder or surveyor.
Why corner blocks often give you more options
Corner sites give designers breathing room.
Instead of squeezing a shared driveway down one side, each townhouse may gain its own street frontage. That can improve privacy, natural light and vehicle access.
We worked with a family in Cheltenham who wanted to retain their existing weatherboard home while building a modern townhouse beside it. Because the site sat on a corner, council supported a cleaner design outcome with independent access for both homes.
The finished result felt less like a subdivision and more like two quality homes sitting naturally within the streetscape.
Driveway access, slope and services can change the budget fast
If you plan to build behind an existing home, driveway access becomes critical.
In many Melbourne councils, a rear dwelling requires a driveway around 3 metres wide. Older homes positioned too close to the boundary can make this difficult.
Slope is another hidden cost.
A relatively flat block is easier and cheaper to develop. Once retaining walls, excavation and complex foundations enter the picture, costs climb quickly.
Then there are underground services.
We recently assessed a site in Bentleigh East where a sewer easement ran directly through the proposed townhouse footprint. On paper, the block looked straightforward. In reality, the design needed major revisions before council would even consider it.
As the saying goes, the devil is in the detail.
The Hidden Legal Issues Sitting on Your Title
Legal restrictions catch many owners off guard.
You can have the right zoning, enough land and strong market demand, yet still hit a brick wall because of something hidden in the title documents.
Easements can limit where you build
An easement is an area of land reserved for infrastructure like:
- Sewer pipes
- Drainage
- Water mains
- Power services
Building permanent structures over easements is usually restricted unless authorities provide written consent.
In practical terms, that can reduce your building footprint or limit where garages, driveways and extensions can go.
Single dwelling covenants can stop multi-home plans
Restrictive covenants are another common issue across older Melbourne suburbs.
Some titles contain clauses limiting the property to one dwelling only. Removing or varying a covenant is possible, but it can become expensive and time-consuming.
We have seen owners purchase sites assuming subdivision was possible, only to discover later that the covenant process would add another 12 months of legal work.
That is a hard pill to swallow after signing a contract.
The Townhouse Subdivision Process Step by Step
Subdivision is a structured process. Most projects take between 9 and 18 months before new titles are issued.
1. Feasibility check and title review
This early stage includes:
- Reviewing zoning and overlays
- Checking easements and covenants
- Assessing nearby townhouse approvals
- Estimating development costs
- Reviewing site access
This is the stage where experienced advice saves money.
2. Site survey and concept design
A licensed surveyor prepares:
- Re-establishment survey
- Features and levels survey
An architect or designer then prepares concept plans that address:
- Overshadowing
- Privacy
- Open space
- Parking
- Building setbacks
3. Town planning application and council review
Council reviews the proposal and may request additional information.
Neighbours are often notified during this stage. Objections may lead to design changes or delays.
Some councils move quickly. Others can feel slower than peak-hour traffic on Nepean Highway.
4. Services, civil works and compliance
Once permits are approved, infrastructure works begin.
This may include:
- Sewer connections
- Stormwater drainage
- Driveways
- Crossovers
- Water connections
- Electrical upgrades
- NBN connections
5. Statement of Compliance and new titles
After all permit conditions are satisfied, council issues a Statement of Compliance.
The Plan of Subdivision is then lodged with Land Use Victoria so new titles can be created.
How Long Does It Take to Subdivide and Build a Townhouse?
Timing depends heavily on council workload, site conditions and service authority approvals.
Here is a realistic guide:
| Stage | Typical Timeframe |
| Initial feasibility | 2–4 weeks |
| Surveys and concept plans | 1–2 months |
| Council planning approval | 6–12 months |
| Subdivision compliance | 3–6 months |
| Townhouse construction | Around 44–56 weeks |
Weather can also play a role. Melbourne winters are not always kind to construction schedules, particularly during excavation and slab preparation.
What Does Subdivision Cost Before Construction Starts?
Many first-time developers focus heavily on building costs while overlooking the soft costs sitting upfront.
These expenses add up quickly.
Professional and authority fees to allow for
Typical pre-construction costs include:
- Land surveyor fees
- Town planner fees
- Architectural drawings
- Engineering reports
- Council application fees
- Water authority fees
- Land registry charges
- Legal costs
A straightforward two-lot subdivision can easily reach $25,000 to $40,000 before construction even begins.
Infrastructure costs many owners forget
Some of the most overlooked expenses include:
- Stormwater upgrades
- Power pit relocation
- Sewer connections
- Driveway construction
- Retaining walls
- Landscaping
- Service trenching
We always recommend keeping a contingency fund of at least 10 to 15 per cent. Building has a habit of uncovering surprises once the ground opens up.
Should You Keep the Existing House or Knock Down and Rebuild?
There is no universal answer here. It depends on your budget, land size and long-term goals.
Keep the front home and build at the back
This approach suits many owner-occupiers.
Benefits can include:
- Lower holding costs
- Rental income potential
- Less demolition work
- Ability to remain living onsite during parts of the project
The challenge is making the existing home work alongside the new dwelling.
Older homes often need upgrades so the finished development feels cohesive.
Knock down and build multiple townhouses
For larger sites, demolition may create a cleaner and more profitable result.
This option often allows:
- Better layouts
- Improved parking solutions
- More efficient construction
- Higher resale appeal
It also comes with higher upfront costs and more complex financing requirements.
How to Improve Your Chances of Council Approval
Council approval is rarely about squeezing the maximum size onto the block.
Good projects respect the surrounding streetscape.
Look for nearby townhouse approvals
One of the best indicators of potential success is nearby precedent.
Walk the surrounding streets. Look for:
- Similar lot sizes
- Comparable setbacks
- Recent townhouse developments
- Shared driveway layouts
- Building heights
If neighbouring sites have successfully subdivided, council may already support that style of development in the area.
Design for the street, not just the spreadsheet
Overdeveloping a site is one of the fastest ways to attract objections.
A quality townhouse project should:
- Protect privacy
- Allow natural light
- Include usable outdoor space
- Fit the neighbourhood character
- Appeal to future buyers
Smart design wins more often than oversized design.
Common Mistakes That Hurt Townhouse Subdivision Projects
We see the same mistakes time and time again:
- Buying a site before checking title restrictions
- Ignoring drainage and service costs
- Assuming large land size guarantees approval
- Choosing builders without townhouse experience
- Overcapitalising for the suburb
- Underestimating council timeframes
- Forgetting contingency allowances
A townhouse project can stack up beautifully on paper, then unravel because one key issue was missed early.
Why the Right Builder Matters Before You Lodge Plans
Many owners speak with designers and planners first, but involving a builder early can prevent expensive redesign later.
A project might satisfy council requirements while still being difficult or costly to construct.
At MJS Construction Group, we often review concept plans before permit lodgement and identify practical construction issues early:
- Access challenges
- Structural complications
- Drainage conflicts
- Service limitations
- Inefficient layouts
That early input can save months of redesign work.
After more than 35 years building across Melbourne, we have learned that successful townhouse developments rely on communication just as much as construction. Clear advice, realistic budgets and proper planning keep projects moving forward without unnecessary stress.
Final Checklist Before You Subdivide Your Block
Before moving ahead, make sure you:
- Check zoning and overlays
- Review the property title carefully
- Confirm driveway access
- Assess slope and drainage
- Review nearby townhouse developments
- Allow for authority and infrastructure costs
- Speak with an experienced townhouse builder
- Keep a contingency budget
- Understand likely council timelines
Subdividing a block and building a townhouse can create strong long-term value when the project is planned properly from the start.
The key is understanding that subdivision is not just about land size. Council controls, title restrictions, site access, drainage and construction costs all shape the final outcome.
The owners who achieve the best results are usually the ones who seek advice early, build realistic budgets and work with experienced professionals who understand Melbourne’s planning environment.
If you are considering a townhouse or dual occupancy project in Bayside or Melbourne’s south-east, speaking with the right team early can save significant time, stress and money later.
