Second-Storey Addition in Bentleigh, Bayside Melbourne
Adding a second storey to an existing single-storey home is the cheapest way to add bedrooms without touching your footprint or losing back-yard space. The catch is that many single-storey homes were not engineered to take an upstairs load. The structural upgrade often costs more than the new upstairs itself.
What to know about Bentleigh
Popular family suburb with post-war homes and a very active rebuild and extension market.
This suburb has an active knockdown-rebuild market. Established blocks, real character stock, and buyers already paying premium prices for good design.
Cost snapshot
Second-Storey Addition build costs in Bentleigh
Base-build rate (mid-range)
$2,700 - $3,600/m²
RLB Q4 2025 — Melbourne, custom (excl. GST)
Typical added area
60–120 m²
Habitable area, indicative
Indicative build cost
$160,000 – $430,000
Base build only; excludes land, site works, fees & GST
Build timeframe
5–10 months
Design to handover
Approval pathway
10–16 weeks
Lodged with City of Glen Eira
Victoria average (ABS)
$485,292 · $1,914/m²
ABS Building Activity 2024–25, completed detached house
Indicative planning figures only — a builder's fixed-price contract is always final. Sourced from RLB Rider Digest (Q4 2025), ABS Building Activity 2024–25, Cotality Cordell CCCI.
Local build notes for Bentleigh
Council
City of Glen Eira
Where people are building
Centre Road precinct, near Bentleigh East, McKinnon border
Typical lots
Post-war 550–700 m² blocks with a very active rebuild and extension market.
Council rules and overlays for second-storey addition in this area
In Victoria, a new build generally needs a planning permit (where the local planning scheme requires one) and a building permit issued by a registered building surveyor. Overlays such as Bushfire Management, Heritage, Significant Landscape and Development Contributions can apply, and growth-area blocks may attract the Growth Areas Infrastructure Contribution (GAIC). Confirm current requirements with your local council and the Victorian Building Authority before finalising a design.
The 3 decisions that shape your second-storey addition in Bentleigh
Structural upgrade scope
Get a structural engineer to assess the existing footings and frame BEFORE design. This determines whether a full second storey, a partial upstairs or a lightweight loft is realistic.
Staircase placement
The staircase eats floor area on both levels. Its location drives every other design decision.
Live in or move out
A full second storey usually requires removing the roof, which means moving out. A partial or lightweight loft can sometimes be done occupied.
Second-Storey Addition FAQs for Bentleigh
Can any single-storey home take a second storey?▾
No. Original engineering has to be checked. Some homes need major structural work first. A structural engineer can advise before design starts.
Is a second storey cheaper than moving?▾
Usually yes, especially in Melbourne's inner and eastern suburbs where you would pay a premium to buy a two-storey equivalent. The maths breaks down if the structural upgrade is major.
Do I need to move out?▾
For a full second storey, usually yes. For a partial or lightweight loft, sometimes not. Confirm with your builder.
Will my house lose character?▾
Only if it is designed poorly. Well-designed second storeys often lift a home's presence rather than detract from it.
Do I need council consent?▾
Yes. Second storey additions require both planning and building consent.
People also ask
Building a second-storey addition in Bentleigh
Which council approves a second-storey addition in Bentleigh?▾
Bentleigh sits in City of Glen Eira. That council administers the planning scheme and any overlays across the suburb, while your building permit and the mandatory inspections run through a registered building surveyor.
Where are new second-storey additions being built in Bentleigh?▾
Most of the building activity in Bentleigh is around Centre Road precinct, near Bentleigh East and McKinnon border.
What lot sizes are typical for a second-storey addition in Bentleigh?▾
Post-war 550–700 m² blocks with a very active rebuild and extension market.