Why this decision is harder than it looks
Most people approach this as a cost question. It's actually a structure question first, then a cost question. A house that looks tired on the outside can have a perfectly solid bones. A house that looks fine can have asbestos, subsidence, or a layout so awkward that no renovation will ever fix it.
The other thing nobody tells you is that major renovations — gutting and rebuilding internally while keeping the shell — can sometimes cost more than a knockdown rebuild because you're paying to work around existing constraints rather than starting clean.
The case for each path
The bones are good
- Structure is solid with no major issues
- Layout can work with reconfiguration
- Heritage listing applies
- You love the character and want to keep it
- Budget is under $300k
- You want to stay in the home during works
Start fresh
- Existing layout cannot meet your needs
- Asbestos or significant structural issues
- You want to maximise the block
- Budget allows $400k or more
- Block orientation suits a new design
- You want full warranty on a new home
The 4 questions to answer before you decide
What condition is the existing structure in?
Get a building inspection before you commit to anything. A $500 inspection can save you $50,000 in renovation surprises. Look specifically for: asbestos (very common in homes pre-1990), subsidence or movement, roof condition, and whether the subfloor is sound.
Can the existing layout actually become what you want?
This is where a designer earns their fee. Some layouts are fundamentally unworkable — wrong orientation, loadbearing walls in the wrong places, insufficient ceiling height. A 30-minute consultation with a designer will tell you whether renovation can get you to your goal or whether you're fighting the building the whole way.
Is the property heritage listed?
If yes, knockdown is likely off the table entirely. Heritage listed properties require council approval for almost any external change and demolition is rarely approved. Renovation becomes your only path — which changes the cost conversation significantly.
What does your block actually allow you to build?
Block size, zoning and overlays determine what a knockdown rebuild can produce. A 450m² block in an R2 zone can fit a generous new home. A 300m² inner-city block may be more constrained. Knowing this before you decide means you're comparing realistic outcomes, not imagined ones.
The real cost comparison
Budgeting for a renovation based on the visible work needed, then discovering the hidden costs halfway through. Asbestos removal, unexpected structural repairs, rising damp, and subfloor replacement are the most common budget blowouts. Always add 15-20% contingency to any renovation budget — more if the home is pre-1980.
Not sure what your block allows?
Before you decide between renovating and rebuilding, you need to know what approvals apply to your property. The ReadyBuild checker tells you in 2 minutes — free.
Check my propertyWhat about approval — does it differ?
Yes — significantly. Demolition always requires approval in NSW. The rebuild can often use the fast-track CDC pathway (no council, approved in 20 working days) if the design meets state standards. A DA through council takes 8-16 weeks.
Renovations vary enormously — minor internal work may need no approval at all, while a major extension requires either a CDC or DA depending on your block and design.
The single most valuable thing you can do before buying: spend 15 minutes with a designer who knows the local planning rules. Not to get plans drawn — just to understand what the block can realistically become. That conversation costs nothing at RO-KA Studio and could save you from the wrong decision.