Dual Occupancy
Duplex Builders Melbourne: Double Your Income From One Block
100%
Customer Focus
70+
Projects Completed
25+
Years of Experience
100%
Custom Homes
The Tombay Experience
Transforms Builder Disappointment Into Your Dream Home
You’ve seen what volume builders deliver. Cookie-cutter designs. Rushed timelines. Zero flexibility when you want to change something.
At Tombay Constructions, we build the home you actually want, not the home that’s easiest for us. Every room purpose-built. Every detail exactly as you imagined. Because after 25 years, we’ve learned that personalised service isn’t optional. It’s everything.
What You May Not Know
The Dual Occupancy Trap: One Quote, Two Very Different Dwellings
You ask three builders to quote your side-by-side duplex. All three come back around $700,000. You pick the cheapest at $680,000.
Four months into construction, you notice the front dwelling getting premium fixtures while the rear dwelling gets budget alternatives. When you question it, the builder shrugs: “Same external appearance, mate. No one said anything about matching the interiors.”
Your rental manager tells you the front unit will achieve $650 per week, but the rear unit with cheaper finishes will only get $420. You’ve just lost $12,000 per year in rental income because the contract didn’t specify matching quality throughout.
Or consider this: your builder quotes mirror-image floor plans to save on design costs. Sounds efficient until you realise the rear dwelling’s living areas face south into your neighbour’s colourbond fence while the front dwelling captures northern sun. One dwelling is light-filled and desirable. The other is dark and difficult to lease.
The dual occupancy market in Melbourne is flooded with poorly designed duplexes where one dwelling clearly got the better orientation, the better street appeal, or the better finishes. These compromises might save $30,000 during construction, but they cost you $15,000 annually in lost rental income for the next twenty years.
The difference between a dual occupancy project that generates genuine dual income and one that delivers one premium dwelling plus one compromise isn’t always visible in the initial quote.
Testimonials
Don’t just take our word for it
“We wanted a builder that was going to do a fabulous job, but also for it to last”
Rachel & Rob
“We wanted a builder that was going to do a fabulous job, but also for it to last”
Rachel & Rob
Expectations Building With Us
What to Expect When Building Dual Occupancy With Tombay
Transparent Pricing From Day One
Your quote includes both dwellings built to matching specifications. We itemise connection costs for services, retaining walls if your site has slope, and any council contribution fees specific to your local government area. You’ll know the total investment before signing anything.
One Project Manager for Both Dwellings
The same person manages your entire dual occupancy build from site preparation through to handover. You won’t get transferred between departments or deal with different contacts for each dwelling. Questions get answered immediately, not passed around.
Matching Quality Throughout
When we say both dwellings are built to the same standard, we mean it literally. Same flooring, same tapware, same appliances, same heating and cooling systems. Your rental income reflects two genuinely comparable properties.
Regular Site Meetings
We meet on site every two weeks to walk through progress together. You’ll see both dwellings taking shape simultaneously and can ask questions while the work is happening, not after it’s completed.
Realistic Timeframes
Most dual occupancy projects take 12-18 months from slab to handover. We don’t promise unrealistic completion dates to win the job, then extend the timeline once you’ve signed. Your build schedule accounts for Melbourne weather, material lead times, and mandatory inspection hold points.
Subdivision Coordination if Required
If you’re planning to subdivide and sell one dwelling, we coordinate with your surveyor and conveyancer to ensure the build meets all requirements for separate titles before construction starts.
Clear, honest communication
Transparent Pricing & Timelines
Quality Craftsmanship
In-House Carpenters
Experienced Team
Meet Lee & The Team: Building Trust Through 25 Years of Custom Craftsmanship
After 25 years in the building industry, Lee started Tombay Constructions with a simple belief. Homeowners deserve better than being passed around between different people, hit with surprise costs, and left wondering if their custom home builder even cares about delivering their vision.
Lee had seen firsthand what happens when builders cut corners or treat custom projects like production lines. Cookie-cutter designs. Rushed timelines. Zero flexibility when you want to change something. That’s not how Tombay operates.
Every Tombay client works with Lee directly. One point of contact. Clear communication about design choices, material selections, and any decisions that need to be made. No confusion about who’s managing your custom build.
We’ve built custom homes throughout Mornington, Rye, Sorrento, and Mount Eliza. We understand local council requirements. We know which suppliers deliver quality materials on time. We’ve established relationships with local trades who share our standards.
This local knowledge means we can navigate the specific challenges of building in Peninsula municipalities. Coastal soil conditions. Heritage overlays. Bushfire regulations. Site access on narrow streets. These aren’t theoretical concerns. We’ve solved them dozens of times.
Rye
Edithvale
Sorrento
Investment Guide To Dual Occupancy
How Much Does It Cost To Build A Dual Occupancy Property In Melbourne?
Complete Dual Occupancy Investment
A complete dual occupancy build in Melbourne typically costs around $1,000,000 to $1,500,000+ for both dwellings, depending on size, specifications, and site conditions. That’s usually in the range of about $400,000 to $700,000 per dwelling.
Per Square Metre Rates
Basic project builder specifications: $2,000 per square metre. Mid-range specifications with quality fixtures: $2,600 to $3,000 per square metre. Inner Melbourne high-specification builds: $3,200 to $3,800 per square metre. These rates apply to 2026 construction in Melbourne and can change.
Development and Professional Costs
Town planning, design, and consultant fees for a dual occupancy planning permit typically total $40,000 to $50,000 if you’re subdividing to separate titles, including town planner input, architectural design, engineering, surveying, and council application fees.
Site works including demolition if removing an existing dwelling: up to $20,000 depending on size, materials, and asbestos.
Structural engineering for shared walls and foundations: $3,000 to $5,000.
Council contribution fees and infrastructure levies vary by local government area and planning controls.
Service Connection Costs
Separate electricity, gas, water, and sewerage connections for each dwelling can add around $8,000 to $15,000 per dwelling on more complex sites, particularly where existing services need upgrades or extensions. Connection timeframes typically require around four weeks, but can stretch longer depending on utility provider scheduling. Sites where services come from the opposite side of the street often face higher connection costs.
Timeline and Holding Costs
Design and planning approval: 4 to 6 months.
Construction from slab to handover: 8 to 12 months.
Total project timeline: 12 to 18 months.
During this period, you’re paying loan interest, land tax, and council rates without rental income, so holding costs need to be built into your feasibility.
Return on Investment
As an example, a dual occupancy might generate around $1,100 per week combined rent (for instance, $650 for the front dwelling and $450 for the rear), which is $57,200 in annual rental income. In many Melbourne suburbs, dual occupancy yields typically sit in the 4% to 6% gross range depending on location, land cost, and total build cost.
Our Process
The steps we take to ensure excellence in every project.
Generate Returns
How Tombay Delivers Dual Occupancy Projects That Generate Equal Returns
Dual Income From Single Title
Keep both dwellings on one title and avoid separate council rates, water rates, and body corporate fees. You pay one set of property costs while collecting two rental incomes. A typical dual occupancy generates $1,100 per week combined rent versus $650 for a single dwelling on the same block.
Multi-Generational Living Solution
Build two separate dwellings that let extended family live independently on one property. Parents in the front dwelling, adult children in the rear. Privacy for everyone, proximity when needed, and no need to coordinate schedules or share living spaces.
Shared Wall Expertise
Side-by-side duplexes require specialist knowledge of acoustic separation and fire ratings between dwellings. We install acoustic insulation, resilient channels, and fire-rated plasterboard systems that exceed minimum code requirements. Your tenants won’t hear each other through the shared wall.
Mirror-Image Design Efficiency
Identical floor plans reversed left-to-right reduce architectural costs and streamline construction. We position both dwellings to capture northern light despite the mirrored layout, ensuring neither dwelling compromises on solar orientation.
Why Choose Us
Are Hidden Building Costs Robbing Melbourne Homeowners?
Every year, hidden costs and budget overruns plague home building projects across Melbourne, turning dream homes into financial nightmares. Don’t let this happen to you. Here’s how Tombay Constructions ensures your dream home stays within reach:
Common Mistakes
Common Dual Occupancy Melbourne Mistakes That Cost Thousands
Buying Land Without Checking Dual Occupancy Eligibility
Property owners purchase blocks assuming they’re suitable for dual occupancy, only to discover council requires greater frontage or site area than their property has. Or a sewer easement prevents the second dwelling. Always verify dual occupancy eligibility before purchasing, not after.
Choosing Builders Without Duplex Experience
Dual occupancy and side-by-side duplex construction require specific knowledge of fire ratings between dwellings, acoustic separation in shared walls, and separate service connections. Builders without duplex experience miss critical details that create ongoing tenant complaints and council compliance issues.
Using Mirror-Image Plans Without Considering Orientation
Mirror-image designs reduce architectural costs but create problems when both dwellings can’t achieve solar access. The front dwelling gets north-facing living areas while the rear dwelling faces south into shadow. One dwelling rents for $650 weekly, the other struggles at $480 because tenants notice the lack of natural light immediately.
Not Planning Service Connections Early
Connecting electricity, gas, water, and sewerage to both dwellings becomes expensive when discovered late. Water mains on opposite street sides require costly road crossings. Electricity transformers lacking capacity need expensive upgrades. Service connection costs that should surface during site assessment become $15,000 to $25,000 surprise variations.
Ignoring Subdivision Setback Requirements
Building both dwellings on single title planning to subdivide later fails when dwellings don’t meet subdivision setback requirements. Dwellings sitting 1.2 metres from boundaries can’t subdivide when council requires 1.5 metres. Check subdivision requirements during design, not after construction.
Areas We Service
Building Dream Homes Across Melbourne’s South-East and Bayside
At Tombay Constructions, we’re proud to serve families and professionals throughout Melbourne’s south-east corridor, Bayside suburbs, and the Mornington Peninsula. Our deep local knowledge means we understand council requirements and neighbourhood nuances unique to each area.
From coastal retreats to family homes in thriving urban communities, we help clients transform their vision into beautifully crafted, custom homes.
Trusted by Families Across These Suburbs
- Mornington
- Mount Eliza
- Dromana
- Parkdale
- Rye
- Aspendale
- Sorrento
- Balnarring
- Portsea
- Chelsea
- Mount Martha
- Flinders
Our Vision
At Tombay Constructions, our vision is to change how people experience building a home. We believe building isn’t about being the cheapest. It’s about being the clearest, with transparent communication and creating spaces that perfectly reflect each client’s style and way of life.
Duplex Builders Melbourne
Duplex builders don’t just construct houses — they create homes that suit modern lifestyles while making the most of every block. At Tombay Constructions, we specialise in dual occupancy and duplex projects across Melbourne’s south-east and the Mornington Peninsula, delivering designs that combine privacy, functionality, and lasting value.
Whether you’re looking to accommodate extended family, generate rental income, or make the most of your investment, our team ensures every project feels thoughtful, personalised, and built to the highest standard. Every duplex we design is tailored to the way people live, with a focus on light, space, and connection to the outdoors.
Duplexes Designed Around You
Every duplex project begins with understanding how the homes will be used and who will live in them. Our team works closely with architects and consultants to design layouts that balance light, flow, and practicality, while ensuring both dwellings feel private and connected to the outdoor environment.
We carefully consider orientation, room proportions, storage, and outdoor areas to create homes that feel spacious and welcoming. At Tombay Constructions, our approach ensures your duplex doesn’t just look good — it works beautifully for those who live in it, providing comfort, functionality, and a sense of home from day one.
Expert Guidance Through Every Stage
Building two homes on one block comes with unique challenges, from council approvals to shared services and site constraints. Working with experienced builders of duplex homes like Tombay Constructions makes the process seamless. We coordinate trades, manage timelines, and offer guidance on materials and finishes so every detail aligns with your vision.
Halfway through a project, the benefits of working with professional duplex home builders in Melbourne become clear — consistent quality, careful attention to detail, and smooth communication all combine to make the process stress-free and predictable, ensuring your investment is protected at every stage.
Maximising Function and Value
Dual occupancy projects aren’t just about building two homes; they’re about creating spaces that feel complete and thoughtfully planned. From parking and storage to outdoor areas and room flow, we focus on designing homes that function for residents today and retain long-term value.
Durable materials, energy-efficient features, and low-maintenance finishes are standard in every project, ensuring the homes are as practical as they are stylish. Each duplex is designed to appeal to future buyers or tenants, enhancing market value while delivering a home you can enjoy now. When you build with Tombay Constructions, you’re investing in homes that perform beautifully for decades.
Confidence From Start to Finish
Choosing the right team is critical for any dual occupancy or duplex project. At Tombay Constructions, our duplex builders in Melbourne combine technical expertise with a personal approach, keeping you informed and involved at every stage. From initial concept through to completion, every element is carefully managed so the final homes feel cohesive, functional, and beautifully finished.
By the time your project is complete, you’ll have two residences that are thoughtfully designed, built with care, and perfectly suited to contemporary living. With Tombay Constructions, building duplexes isn’t just construction — it’s about working with duplex builders who understand how to create homes that provide comfort, flexibility, and enduring value for the people who live in them. Every detail reflects our commitment to quality, practicality, and timeless design.
Get in touch
Reach out to see how we can bring your ideal property to life. Experience a seamless building journey with Tombay Constructions.