Subdividing your property and building a second dwelling can be an excellent way to unlock the value of your land, create a new home for family members, generate rental income or prepare part of the property for sale
Subdividing your property and building a second dwelling can be an excellent way to unlock the value of your land, create a new home for family members, generate rental income or prepare part of the property for sale
Subdividing your property and building a second dwelling can be an excellent way to unlock the value of your land, create a new home for family members, generate rental income or prepare part of the property for sale.
However, a dual occupancy project involves much more than selecting a home design and calculating the construction cost.
Whether you are considering building a new home behind an existing dwelling, constructing at the front of the property or replacing the original house with two new homes, there are several planning, subdivision and infrastructure requirements that may need to be addressed before the building stage can begin.
At Bevnol Homes, we believe property owners should understand the broader project costs early, so they can make informed decisions before investing heavily in plans and permits.
Not every block can be developed in the same way.
The property’s zoning, overlays, frontage, dimensions, easements, slope, access, existing services, vegetation and surrounding development can all influence what may be possible.
The location and condition of the existing dwelling also need to be considered. A house positioned close to one boundary may leave space for a second dwelling, while another property may require significant alterations, demolition or changes to vehicle access.
Before progressing too far, it is important to establish whether the proposed development is likely to satisfy local planning requirements and whether the property can practically accommodate another home.
A licensed land surveyor may be required to prepare a proposed plan of subdivision showing how the land could be divided.
This process can include reviewing title information, existing boundaries, easements, access arrangements, private open space and the proposed location of each dwelling.
A re-establishment survey may also be required to accurately confirm the property boundaries before design or construction work begins.
Boundary discrepancies can create major issues later, so relying on old fencing or approximate measurements is not sufficient for a development project.
Dual occupancy developments will often require a planning permit through the relevant local council.
An experienced town planner can help assess the planning controls affecting the property, prepare the planning submission and respond to council requests during the approval process.
The planner may need to address matters such as:
Neighbourhood character
Building height and setbacks
Overlooking and overshadowing
Private open space
Vehicle access and car parking
Landscaping
Site coverage
Stormwater management
The relationship between the new and existing dwellings
Planning approval can take time, particularly where council requests further information, changes to the design or specialist reports.
Property owners should allow for this when considering their overall project timeframe.
A dual occupancy development can require more documentation than a standard new home build on an uncomplicated vacant block.
Depending on the property and council requirements, additional investigations may include:
Land surveying
Feature and level surveys
Town planning reports
Arborist reports
Traffic assessments
Stormwater or drainage reports
Civil engineering
Landscape plans
Bushfire assessments
Acoustic reports
Soil testing
Service location investigations
Easement and title reviews
Not every project will require every report, but it is important to identify the likely requirements early.
Each specialist consultant adds cost and may also affect the approval timeline.
Stormwater management is an important part of a dual occupancy development.
Council or the relevant authority may require a full drainage design showing how stormwater from both dwellings, driveways and other hard surfaces will be collected and discharged.
The project may require new drainage connections, on-site detention, water tanks, pumps, pits or upgrades to existing systems.
Drainage can become particularly complex where the property slopes away from the street or where there is no simple legal point of discharge.
These costs are separate from the standard construction price of the new dwelling and need to be allowed for within the overall development budget.
The existing electrical supply may not be adequate for two dwellings.
A new electrical pit, upgraded connection or three-phase electrical supply may be required. Depending on the site and authority requirements, this can cost thousands of dollars.
Further costs may apply for underground power, meter locations, switchboard upgrades, trenching or alterations to the electricity supply for the existing home.
These works often involve external authorities and contractors, which means they may sit outside the builder’s standard construction price.
Consent from the relevant water authority may be required before the subdivision or development can proceed.
This may involve application fees, new water connections, sewer connection works, asset protection requirements or contributions toward authority infrastructure.
The cost can vary considerably depending on the location of existing services and whether separate connections are required for each dwelling.
Obtaining water authority consent and completing the required infrastructure works can cost thousands of dollars and may take additional time.
When retaining the existing dwelling, it is important not to assume it can remain completely unchanged.
Modifications may be required to make the overall development compliant or functional.
These could include:
Relocating windows to address overlooking
Installing screening
Modifying private open space
Changing the driveway or crossover
Relocating services
Updating drainage
Removing garages, sheds or verandahs
Altering fencing
Upgrading electrical infrastructure
Completing fire separation works
Adjusting access around the existing home
The condition of the existing dwelling should also be reviewed. It may not make financial sense to retain a house that requires extensive repairs or alterations to support the proposed development.
A dual occupancy project involves several stages before construction can start.
These may include:
Preliminary site and planning assessment
Surveying and property investigations
Concept design
Town planning documentation
Planning permit assessment
Further information requests or design amendments
Engineering and drainage documentation
Authority approvals
Subdivision documentation
Building permit approval
Service upgrades and site preparation
Construction
Planning permits, authority approvals and subdivision processes can take months. Delays can also occur where additional information is requested or where infrastructure upgrades are required.
A realistic timeframe should include the entire development process, not only the construction period.
When calculating whether a dual occupancy project is financially viable, property owners should consider costs that may sit outside the new home building contract.
These can include:
Surveyor fees
Town planning fees
Council application fees
Specialist reports
Engineering and drainage design
Water authority fees
Sewer and water connections
Electrical supply upgrades
New pits and meters
Driveways and crossovers
Landscaping
Demolition or removal of existing structures
Modifications to the existing dwelling
Subdivision certification
Titles office and legal costs
Finance and holding costs
Contingency allowances
A project that initially appears straightforward can become significantly more expensive once these items are properly investigated.
The most important advice we can give is to complete your research before assuming a second dwelling will fit, gain approval or remain within your intended budget.
Speak with suitably qualified consultants, investigate the planning controls, understand the authority requirements and obtain realistic estimates for the non-construction costs.
Early due diligence may involve upfront expense, but it can prevent much larger costs later.
Bevnol Homes works with clients across Melbourne, the Mornington Peninsula, Bayside, Frankston, Langwarrin, Pearcedale, Warragul, Drouin and surrounding areas on custom homes, knockdown rebuilds, dual occupancies and townhouse developments.
Our designs are starting points. We can review the land, understand how you want to use the property and reimagine a design to suit the site, planning requirements and your broader development goals.
Before focusing solely on the new home price, we encourage clients to look at the complete project.
Bring us your property details, existing plans or early development ideas and we can help you understand the next steps and the questions that need to be answered.
Please note: Planning, subdivision and authority requirements vary between properties and municipalities. Independent advice should be obtained from the relevant council, licensed surveyor, town planner, authorities and other qualified consultants before proceeding.