Renovate or extend when the house is structurally sound, the layout can be fixed, and what you are really short of is space or updated rooms. Knock down and rebuild when the structure is failing, the layout fights you in every room, or the work needed to fix the old house would approach the cost of a new one. We build new homes and extensions, so we have no reason to push you either way, and we'll tell you straight which one your house and block point to.
Signs renovating or extending is the smart money
- The footings, frame and roof are in good condition, with no major movement cracking.
- You like the location and the block, and the house mostly works; you need another bedroom, a second living area or a bigger kitchen.
- The problem rooms are the usual suspects: a tired kitchen, a dated bathroom, a closed-in living area that could be opened up.
- Your block has room to extend out, or the structure can take a second storey.
Much of northern Adelaide fits this description. Plenty of homes in suburbs like Munno Para and Elizabeth were built decades ago with solid structure but tired kitchens, bathrooms and floorplans. A well-planned renovation and extension can turn those into very different homes. Our guides to extension costs and building out vs going up help with that side of the decision.
Signs a knock down rebuild is worth pricing
- Significant structural problems, such as footing movement on reactive clay, failing walls or a roof that needs replacing.
- A layout that needs changing almost everywhere, not just in one or two rooms.
- The renovation list keeps growing: rewiring, replumbing, new windows, new floors, asbestos removal, re-roofing.
- You want a home that meets current standards for comfort and running costs.
- Your zone allows a bigger or two-storey home that would suit the family for decades.
On the standards point: from 1 October 2024, the NCC 2022 modern homes provisions apply to new homes in South Australia (subject to transitional arrangements). They include 7-star equivalent energy ratings (up from 6), a whole-of-home annual energy budget, and livable housing design features such as a step-free entry and wider doors and corridors (PlanSA). A rebuild gets you all of that from day one. An older house can be improved a lot, but rarely to the same level.
What a knock down rebuild involves in SA
- Check the property's zone and overlays on PlanSA's Zoning for a property tool. Heritage and character overlays can restrict demolition, and the zone sets what you can build in its place.
- Asbestos survey. SafeWork SA says homes built or renovated before the mid-1980s are highly likely to contain asbestos. Friable asbestos must be removed by a licensed asbestos removalist, and SafeWork SA recommends a licensed removalist for large amounts of non-friable asbestos too (SafeWork SA).
- Approvals for the demolition and the new home. PlanSA lists demolition as development that needs building consent, and building a house needs planning consent as well (PlanSA, Types of consent).
- Disconnect services (power, water, gas, sewer) before demolition, then reconnect for the new build.
- Soil test and site classification for the new footings.
- Building indemnity insurance for work that needs council approval and costs $20,000 or more, with the certificate to you and the council before work starts (SA.GOV.AU).
- Demolition, site works, slab, frame, lock-up, fit-out and handover.
Costs to compare honestly
Comparing a rebuild with a renovation on headline prices alone is misleading. Put these side by side:
| Knock down rebuild | Renovate and extend |
|---|---|
| Demolition, asbestos removal, service disconnection | Asbestos removal where works disturb it |
| Design, engineering, approvals for a whole new home | Design, engineering, approvals for the extension |
| Full new build, built to current standards | New work plus bringing old parts up to standard where they're touched |
| Rent or somewhere else to live for the whole build | Possibly living on site, or moving out for part of it |
| Few surprises once the slab is down | More unknowns behind walls, under floors and in the roof |
We don't publish a standard price for either, because the house, block and finishes drive everything. What we do is price both paths properly when a rebuild is a real option, so you are comparing like with like.
How we help you decide
We're licensed builders (BLD 360698) who build custom new homes as well as home extensions and renovations. If a knock down rebuild is the better path, we can manage the demolition, design and new build as one coordinated project. You can see three of our completed custom homes in Riverlea Park in our portfolio.
Common questions
Do you need approval to demolish a house in SA?
Yes. PlanSA lists demolition as development that needs building consent. The new home also needs planning consent and building consent, and if the property is under a heritage or character overlay, demolition can be restricted, so check the zoning first.
Is it cheaper to knock down and rebuild than to renovate?
It depends on the house. A rebuild avoids the unknowns of an older structure and delivers current energy and livability standards, but adds demolition and a full new build. When the structure is sound and you mainly need space, renovating and extending is usually the better value. We'll price both if a rebuild is genuinely on the table.
What about asbestos in an older Adelaide home?
SafeWork SA says homes built or renovated before the mid-1980s are highly likely to contain asbestos. Friable asbestos must be removed by a licensed asbestos removalist, and a licensed removalist is recommended for large amounts of non-friable material.
Can ASP Build & Co manage a knock down rebuild?
Yes. We can manage the demolition, design and new build as one coordinated project, with one point of contact from the first conversation to handover.
Related pages
Sources
- PlanSA, NCC 2022 modern homes provisions
- PlanSA, Types of consent
- PlanSA, Zoning for a property
- SafeWork SA, A DIY guide to asbestos safety for home renovators (30 March 2026)
- SA.GOV.AU, Building indemnity insurance (updated 19 February 2026)
Rules and published figures checked on 5 October 2026. Third-party cost ranges are not ASP Build & Co prices; we quote every job individually after a site visit.
