Second Storey Extension Melbourne Cost Breakdown

Second storey extension Melbourne cost varies dramatically based on your specific requirements and location. Most homeowners underestimate the true investment needed for a quality double storey addition.

We at Cameron Construction see budgets range from $150,000 to $400,000 depending on size, finishes, and council requirements. Understanding these cost factors upfront prevents expensive surprises during construction.

What Drives Second Storey Extension Costs

Structural Engineering Requirements

Structural engineering creates the largest cost variable in second storey extensions. Melbourne’s varied soil conditions demand comprehensive foundation assessments before builders add upper levels. Clay soil areas like Glen Waverley and Doncaster require deeper footings and reinforced foundations, which add $15,000 to $30,000 to project costs.

Existing timber frame homes need significant structural upgrades that include steel beam installations and wall reinforcements. The Building and Plumbing Commission requires detailed structural drawings for all second storey work, with engineering fees that range from $8,000 to $15,000 based on complexity.

Council Permits and Planning Costs

Planning permit fees across Melbourne councils vary dramatically based on project value and location. Boroondara Council charges $1,462.50 for extensions valued up to $500,000, while heritage overlay areas incur additional assessment fees of $2,000 to $5,000.

Building permit costs start at $500 for basic applications but increase substantially for complex designs. Asset protection permits range from $2,000 to $2,500 per street frontage as refundable bonds (with minimum requirements per street frontage). Council inspection fees add another $800 to $1,200 throughout construction phases.

Heritage areas require specialised consultants who add $3,000 to $8,000 in professional fees to your project budget.

Material Selection Impact

Material choices create the widest cost spread in second storey extensions. Standard brick veneer costs $180 per square metre while premium rendered finishes reach $350 per square metre. Roof materials range from $45 per square metre for Colorbond to $120 per square metre for concrete tiles.

Window specifications dramatically affect budgets with standard aluminium frames at $800 per square metre compared to thermally broken systems at $1,400 per square metre. Hardwood floors add $100 to $200 per square metre over standard carpets (depending on timber species and finish quality).

Quality insulation and weatherproofing materials increase upfront costs by 15% but reduce long-term energy expenses significantly. These material decisions directly influence the permit requirements and council approval processes that follow.

What Do Melbourne Council Permits Really Cost

Melbourne councils impose dramatically different permit fees that directly impact your extension budget. Planning permit fees vary significantly across councils, while Stonnington Council applies different fee structures based on development complexity. Yarra Council adds heritage assessment fees of $2,000 to $5,000 for properties in overlay zones, which makes location selection critical for budget planning.

Planning Permit Variations Across Councils

Port Phillip Council requires additional traffic management permits that cost $283 for short-term construction zones and extend to $1,415 for projects that exceed 30 days. Darebin Council imposes asset protection bonds of $2,500 per street frontage as refundable deposits, while Whitehorse Council charges lower bonds of $2,000 for similar works. Building permit application fees start at $500 across most Melbourne councils but increase to $900 for complex Class 4 residential extensions. Mandatory inspections add $200 to $300 per stage, with foundation, frame, and final inspections required for all second storey work.

Heritage Compliance Costs

Heritage overlay areas demand specialised heritage consultants who charge $3,000 to $8,000 for impact assessments and design modifications. Fitzroy and Carlton properties face additional conservation architect fees of $5,000 to $12,000 for detailed heritage reports. These heritage areas require materials that match existing facades, which increases construction costs by 20% to 35% compared to standard extensions. Council heritage officers often request design revisions that add 6 to 8 weeks to approval timelines (affecting overall project schedules and holding costs).

Asset Protection and Temporary Permits

Construction zones require temporary traffic management permits that vary significantly between councils. Moreland Council charges $132 for construction zone applications plus daily occupancy fees based on square metres occupied. Melbourne City Council imposes higher fees of $200 to $400 for similar permits in high-traffic areas. Asset protection bonds protect council infrastructure during construction, with most councils requiring $2,000 to $2,500 per street frontage. These bonds return after successful project completion and infrastructure inspection.

These permit costs represent just the regulatory foundation for your project. The actual construction expenses create the major budget considerations that determine your final investment.

What Do Real Melbourne Extensions Actually Cost

Second storey extensions in Melbourne cost between $2,800 and $4,500 per square metre for standard specifications, while premium finishes push costs to $5,500 per square metre. A typical 80 square metre second storey addition ranges from $224,000 to $360,000 based on material selections and structural complexity. Smaller 50 square metre extensions start at $140,000 for basic specifications but reach $275,000 with premium finishes like hardwood floors, stone benchtops, and high-end fixtures.

Standard Versus Premium Specification Costs

Standard specifications include painted brick veneer, Colorbond roofing, laminate benchtops, and carpet floors which cost approximately $3,200 per square metre. Premium specifications feature rendered facades, concrete roof tiles, stone benchtops, and hardwood floors that increase costs to $4,800 per square metre. The Building and Plumbing Commission requires identical structural work regardless of finish quality, which means premium selections only affect interior and exterior materials rather than foundation or frame expenses.

Hidden Costs That Destroy Budgets

Soil tests reveal clay conditions in Melbourne properties, which adds $18,000 to $35,000 for deeper footings and reinforced foundations. Asbestos removal affects homes built before 1990 and costs $8,000 to $25,000 based on contamination extent. Utility relocations (gas, electricity, and NBN connections) add $3,500 to $8,000 per service. Council infrastructure contributions range from $2,500 to $12,000 based on property location and development impact assessments.

Project Contingencies That Matter

Professional builders recommend 15% contingencies for standard extensions and 20% for heritage properties due to unexpected structural discoveries. Weather delays cost $500 to $800 per week in expenses that include site security and equipment rental. Material price fluctuations affect projects longer than six months, with steel and timber prices that increase 8% to 12% annually since 2022. These contingencies protect against cost overruns that force project delays or specification compromises.

Labour and Subcontractor Expenses

Labour costs account for 30% to 35% of total project expenses in Melbourne’s competitive construction market. Skilled tradespeople charge premium rates (particularly electricians and plumbers who handle complex second storey installations). Seasonal labour shortages during peak construction periods increase costs by 10% to 15% compared to winter months when demand drops significantly.

Final Thoughts

Second storey extension Melbourne cost varies from $150,000 to $400,000 based on structural requirements, council permits, and material selections. Heritage properties, clay soil conditions, and utility relocations create budget surprises that proper planning prevents. Professional consultation stops expensive mistakes when homeowners underestimate structural needs or council compliance requirements.

We at Cameron Construction handle concept to completion projects with extensive experience in Melbourne’s complex regulatory environment. Our team manages permits, BCA compliance, and construction phases that protect your investment. Start with soil testing and structural assessments before you finalise budgets.

Obtain multiple quotes from licensed builders who understand Melbourne council requirements. Budget 15% to 20% contingencies for unexpected costs that affect most extension projects (particularly heritage properties). Professional builders prevent cost overruns that force project delays or specification compromises.