Rebuild or renovate
Knockdown rebuild or
renovate in Melbourne?
The honest answer is a threshold, not a preference. If your renovation is heading past roughly 55% of what a new build would cost, a rebuild usually delivers more house for the money. Below that, renovating almost always wins. Here is how to work out which side of the line you are on.
New builds cost less per square metre than extensions
New construction is cheaper per square metre than extending. Industry figures put a standard-to-mid-range Melbourne build at roughly $2,100 to $3,900 per square metre, while extension rates start at $2,700 and run to $5,100.
That surprises people, and the reason is simple: an empty block is the easiest thing a builder will ever work on. No propping, no matching existing brickwork, no working around a family living in half the house, no discovering that the 1920s stumps have gone. You are paying a premium to keep the old building, and on a sound house that premium is worth it. On a failing one, it is not.
Knockdown rebuild cost in Melbourne
| Knockdown rebuild | Notes | Typical |
|---|---|---|
| Demolition | Brick and concrete cost more than timber; asbestos adds more again | $15k – $45k |
| Design, permits and consultants | Includes a Section 29A demolition consent where required | $12k – $35k |
| Construction | $2,100–$3,900/m²; premium custom builds run past $5,000 | $300k – $700k+ |
| Temporary accommodation | You cannot live on a construction site — this is not optional | $8k – $40k |
| Landscaping and external works | A new build leaves you a bare block | $10k – $50k |
| Total, typical Melbourne project | Four-bedroom double storey, middle suburbs: $550k – $750k | $450k – $900k |
Rebuild figures: published Melbourne market data, 2026 · Extension and renovation rates: Archicentre Australia CostGuide 2026
Against that, a major renovation of a pre-1940 house — a rear extension plus reworking the existing footprint, with wet areas, restumping, rewiring and re-plumbing — commonly lands between $400,000 and $700,000 in the inner suburbs. The two overlap far more than most people expect, which is exactly why the decision is genuinely difficult.
Should you rebuild or renovate? Four tests
Work through these in order. The first one often ends the conversation.
1. Is there a heritage overlay?
If there is, demolition of the significant fabric is usually off the table regardless of the economics. Much of the inner north, inner east and bayside sits under one. Check your planning property report first — it is free and it decides everything downstream.
2. How much of the house are you keeping?
If the plan retains less than about 40% of the existing structure, you are paying renovation rates for something close to a new build. That is the clearest signal to price both.
3. Is what you are keeping actually sound?
Failed stumps, unsafe wiring, old plumbing and asbestos are around $26,000 of work on pre-war stock before you add a square metre. If the bones are poor, the premium you are paying to keep them buys very little.
4. Do you want the old house?
Not a financial question, and it does not need to be. Period detail, a mature garden and a street you love are real things. Just make the decision knowing what the preference costs rather than assuming it is free.
Where rebuilding wins
Large flat blocks with light heritage coverage — much of Balwyn, parts of Brighton, the middle-ring east generally. Post-war housing you feel no attachment to. Sites where you want a fundamentally different layout rather than more of the same one. And any project where the renovation scope has crept until you are keeping four walls and a roofline.
Where renovating wins
Anything in a heritage overlay, where rebuilding is usually not permitted. Sound interwar and post-war construction where the existing structure genuinely does the job. Projects where you only need one more room. And constrained inner-city blocks, where a new build faces the same access, party-wall and approval problems the renovation would, without the offsetting saving.
There is also a timing argument. A rebuild means moving out for the whole build — commonly 12 to 24 months from design to handover. A rear extension often lets you stay in the front of the house for most of it. On a long project that difference is worth tens of thousands in rent you never see itemised anywhere.
Overcapitalising — the trap on both paths
Overcapitalisation. Every street has a price ceiling, and spending past it is money you do not get back at sale. This bites harder on rebuilds because the budgets are larger and the temptation to specify upward is stronger once you are starting from nothing.
Before committing to either, find out what the best house in your street has actually sold for. If your land plus your build lands above that number, you are buying lifestyle rather than making an investment. Which is a perfectly reasonable thing to do — but it should be a decision, not a discovery.
Price the renovation first
You cannot apply the 55% test without a renovation number. Eight questions, and you will see every line of the calculation.
Common questions
Is a knockdown rebuild cheaper than renovating in Melbourne?
Sometimes, and more often than people expect on older houses. New construction runs about $2,100 to $3,900 per square metre against $2,700 to $5,100 for extensions, because building on a clear site avoids the cost of working around an existing structure. The usual threshold is that if a renovation is heading past roughly 55% of the cost of a new build, a rebuild delivers more house per dollar.
How much does demolition cost in Melbourne?
Between $15,000 and $45,000 for a standard home, averaging around $18,000 to $30,000 for a single storey. Brick and concrete cost more than timber-framed houses, and asbestos requires licensed removal on top.
Can I knock down a house in a heritage overlay?
Usually not the significant fabric. Heritage overlays exist to prevent exactly that, and demolition applications on contributory or individually significant buildings have a low success rate. Check your planning property report before considering a rebuild — it is the first question, not a detail.
How long does a knockdown rebuild take?
Commonly 12 to 24 months from initial design through to handover. Demolition itself is quick, usually two to four weeks, but design, planning and building approvals take months and construction runs eight to fourteen.
What is the total cost of a knockdown rebuild in Melbourne?
Most projects fall between $450,000 and $900,000 all in, with a four-bedroom double-storey home in the middle suburbs typically landing at $550,000 to $750,000. That covers demolition, permits and design, construction, temporary accommodation and landscaping.
Will I need to move out?
For a rebuild, yes, for the entire build. Budget $8,000 to $40,000 depending on how long it runs and where you rent. A rear extension often lets you stay in the front of the house for most of the project, which is a real saving that no cost guide itemises.
Related
When you are ready to build
AE Index is not a building company. When a project is ready to be priced properly, we pass it to a builder from our verified network — who will walk the site, inspect what is under the floor, and put a fixed price in writing. We are paid a fee by them on work that proceeds, and you are under no obligation to use them.
Plenty of directories call their builders trusted without saying what that means. Ours means five specific things:
- Current domestic builder registration, confirmed with the Victorian Building Authority
- Domestic building insurance current and sighted
- Two completed projects contacted directly — not supplied testimonials
- Fixed-price contracts with a written variations policy
- Re-checked annually, and removed from the network on any lapse
The sensible order is estimate first, referral second. Run the numbers, decide whether the project is viable, and only then talk to a builder.
Last updated 28 July 2026