A single storey rear extension is the most common type of home extension
in Melbourne. It expands the ground floor living area, typically adding
a new kitchen, dining, and living area that opens to the garden. Costs
typically range from $2,500–$5,000 per square metre including
structural work, finishes, and glazing. A 40sqm extension costs
$100,000–$200,000.
Pros: Generally lower planning risk, simpler structural requirements,
maintains connection between indoor and outdoor living, faster to build.
Cons: Uses garden space, limited bedroom addition without converting
other rooms, may not add as much value per dollar in high-value suburbs.
Double Storey Extension: Pros and Cons
A double storey extension adds living space on two levels, typically
adding bedrooms and bathrooms upstairs while creating new ground floor
living areas. Costs are higher — typically $3,500–$6,000 per square
metre — but the cost per square metre of new space is often better
than a single storey extension because you’re building up rather than
out.
Pros: Maximises value from footprint, adds bedrooms (high value in
Melbourne), preserves garden space, can significantly transform a modest
home. Cons: Higher planning scrutiny (overlooking, overshadowing), more
complex structural requirements, longer build time.
Which Adds More Value?
In Melbourne’s inner and middle-ring suburbs, adding bedrooms and
bathrooms via a double storey extension typically achieves a higher
return on investment — particularly for three-bedroom homes that
become four or five bedroom homes. In outer suburbs where land is more
affordable and garden space is valued more highly, single storey
extensions may perform comparably.
Planning Considerations in Melbourne
Double storey extensions face more planning scrutiny than single storey
additions. Key issues include: overlooking (windows and balconies must
not overlook neighbouring private open space or habitable rooms within 9
metres), overshadowing (must not reduce solar access to neighbouring
properties below prescribed minimums), and neighbourhood character
(height and massing must be compatible with the neighbourhood). Single
storey extensions have lower hurdles but still need to meet setback
requirements.
Frequently Asked Questions
Does a double storey extension require a planning permit in
Melbourne?**
It depends on the council, zone, and specifics of the design. Many
double storey extensions are exempt from planning permits under the
VicSmart process or as of right development, but this depends on
specific zone provisions and whether the design meets all prescriptive
standards.
How long does an extension take to build in Melbourne?
Design and permits: 3–6 months. Construction: 4–8 months for single
storey, 6–12 months for double storey. Living in the property during
construction is challenging but possible with good site management.
Ready to Get Started? Contact Integral Design Solutions today for
expert extension design and project management services in Melbourne
and Victoria. Visit integraldesignsolutions.com.au/ or call us to book
a free consultation.
