Guest article · Building and renovating
Renovate or rebuild? How to make the call on a Sydney home
Quick answer: Renovate when the structure is sound, you like most of the layout and the work is limited to a few rooms. Rebuild when the footings, frame, roof and services all need replacing, when the renovation quote gets close to the price of a new build, or when the house can't give you the layout you want. Get a building and pest inspection before you decide.
If you own an older house in Sydney, you've probably stood in the kitchen and asked whether to fix the place up or knock it down and start again. I get asked this almost every week. The answer depends on a handful of things you can check, in this order.
Renovate or rebuild at a glance
Five questions settle most cases. If three or more of your answers sit in the rebuild column, get a rebuild quote before you commit to renovating.
| Question | Points to renovating | Points to rebuilding |
|---|---|---|
| Structure | Sound footings and frame, a roof with life left in it | Cracked or sinking footings, termite damage through the frame, a roof due for full replacement |
| Services | Wiring and plumbing mostly up to date | Old wiring and plumbing throughout |
| Layout | It mostly works; you want better rooms, not different ones | You want a layout the house can't give you |
| Scope | A kitchen, bathrooms, opening up a living area, a deck | Most of the house would be replaced anyway |
| Price | The quote is well under a comparable new build | The quote is getting close to new-build pricing |
The author's rules of thumb from his own building work, not an official test. Sources are listed at the end of this guide. Checked 10 November 2026. General information, not building, legal or financial advice.
Start with the structure
A house with solid footings, a sound frame, a decent roof and a layout that mostly works is a good renovation candidate. Once you are replacing most of the house, you are paying renovation prices for what is basically a rebuild.
Before you get excited about floor plans, look at what you're working with. With a sound structure you can update kitchens and bathrooms, open up living areas and add a deck without touching the bones much.
It gets harder when the problems are structural: cracked or sinking footings, termite damage through the frame, a roof that needs full replacement, or old wiring and plumbing throughout. Each one adds up quickly, and none of them gives you the freedom a fresh design does.
Get the inspections done first
Have a building inspection and a pest inspection done before you price either option. The NSW Government's advice is to use a suitably qualified person, such as a licensed builder, a surveyor or an architect, for the building report. That report won't generally cover termites, which is why you get a separate pest inspection.
Asbestos and lead paint
These are not do-it-yourself jobs, and this article doesn't cover removing either. What you need to know for the decision:
- A home built before 1990 is likely to contain asbestos, and one renovated between 1990 and 2004 may, according to the NSW Government's asbestos site. It also warns that building reports don't always cover asbestos.
- In NSW, removing more than 10 m² of non-friable asbestos, or any amount of friable asbestos, needs a licensed asbestos removalist.
- Lead paint is most likely in homes built before 1970, according to the Australian Government's YourHome guide.
Ask for an asbestos assessment before any demolition or strip-out, and price the removal into both options. For advice, call 1800 Asbestos (1800 272 378) or see asbestos.nsw.gov.au.
The cost question
A cosmetic or mid-level renovation usually costs less than rebuilding. A big renovation often doesn't, because the price keeps growing after the walls come off. Compare a renovation quote and a rebuild quote for the same floor area and finish level.
People often assume renovating is always cheaper. Big renovations have a habit of growing. Once walls come off, you find things you couldn't see, and every one of those discoveries is a variation on your contract.
A knockdown rebuild has demolition and site costs up front, but the pricing tends to be more predictable because you're building new from a set of plans.
What the numbers look like in Sydney
These are Buildana's own published estimates, not quotes for your block. They exclude GST unless stated and were last updated in 2026:
- Knockdown rebuild: $565,000 to $1.27 million plus GST for the build, or about $2,820 to $4,250 per m² (Buildana's knockdown rebuild cost guide, updated 8 November 2026).
- Full-house renovation: $120,000 to $250,000. A ground-floor extension runs $2,200 to $3,800 per m² and a second storey $2,800 to $4,500 per m² (Buildana's renovation cost guide, 25 March 2026).
As an independent check, quantity surveyor BMT's 2026 cost table puts a new four-bedroom, two-level brick veneer house in Sydney at $3,167 to $4,154 per m² before GST, depending on the finish.
The rates per square metre overlap. That is the point: a second storey can cost as much per square metre as a new house, on top of a ground floor you haven't improved.
Running costs
A new home has to meet today's BASIX standards. Since 1 October 2023 that has meant a 7-star thermal performance rating for most new houses in NSW, and the NSW Government says the higher standards could save a household as much as $980 a year on energy bills. BASIX also applies to renovations: any alteration or addition valued at $50,000 or more needs a BASIX certificate.
If the renovation is getting close to the cost of a new build, the rebuild is often the smarter money.
Approvals: exempt, CDC or DA
There are three paths in NSW. Small low-impact work can be exempt development. A project that meets the set standards can get a complying development certificate (CDC) in as little as 20 days. Everything else needs a development application (DA) to your council.
This is the part that trips a lot of people up in Sydney. A CDC is the fast track: one combined planning and construction approval, issued by your council or a private certifier. A DA is assessed on its merits by the council and takes longer.
Your block decides which path you get, not your builder. Under the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, complying development is not allowed:
- on a heritage item, and for most work in a heritage conservation area
- on bush fire prone land rated BAL-40 or in the flame zone
- on a flood control lot, unless that part of the lot is certified as outside the flood storage area, floodway, flow path and high hazard or high risk areas.
A section 10.7 planning certificate from your council shows the zoning and the constraints on the property, including flooding and bush fire prone land. Get one before you pay for designs.
Demolishing a house needs approval too, usually a CDC under the Demolition Code, and you must notify your neighbours before the work starts. Check before you start pulling things out.
| Path | What it covers | How long |
|---|---|---|
| Exempt development | Minor, low-impact work that meets the set standards, such as a deck, a carport or repairing a window | No planning approval needed |
| Complying development (CDC) | Straightforward projects that meet the standards in the code, including many new houses and some renovations | As little as 20 days |
| Development application (DA) | Anything that is neither exempt nor complying, including most work on constrained blocks | 84 days on average across NSW (31 May 2026) |
DA times vary a lot by council. In the October 2026 snapshot of the NSW council league table, the average was 56 days at the City of Sydney, 90 at Parramatta and 116 at Blacktown. The NSW Government's target for councils is 90 days from 1 July 2026. Exempt development cannot be carried out on land on the State Heritage Register. Sources are listed at the end of this guide. Checked 10 November 2026. General information, not building, legal or financial advice.
Work on a NSW house is exempt development, complying development or needs a development application. Timeframes and the land where complying development is not allowed are in the table and text beside this diagram, with their sources.
Read the illustration as text
- Exempt development
- Minor, low-impact work that meets the set standards.
- Complying development
- A fast-track certificate from a council or a certifier.
- Development application
- A merit assessment by your council for everything else.
Your block decides the path, not your builder.
Timelines and where you'll live
A new house in NSW took about nine months on average from the start of construction to completion in 2025-26, before you count design, approvals and demolition. A rebuild means moving out for all of it, so budget for rent on top of the build.
The Australian Bureau of Statistics tracks how long new houses take from commencement to completion. In NSW the average was 2.99 quarters in 2025-26, about nine months. Five years earlier it was 2.36 quarters, about seven months, and it peaked at 3.39 quarters in 2023-24. So build times have stretched, and they are only now coming back.
That figure starts when construction starts. It doesn't include design, approvals or demolition, so ask your builder for a proper program in writing, not a guess.
A renovation can sometimes be staged so you live in part of the house while the work happens. Anyone who has done this will tell you it's dusty and stressful. A rebuild means moving out for the whole build.
What your contract must include
In NSW the law sets the basics for any residential building contract, whether you renovate or rebuild: a written contract, a capped deposit, insurance and statutory warranties.
From the NSW Government's contract rules:
- Written contract: required for any job over $5,000 including GST. Jobs over $20,000 need the more detailed contract, and you get a cooling-off period of five clear business days.
- Deposit: no more than 10% of the contract price.
- Insurance: for jobs over $20,000, your builder must have home building compensation cover. Don't pay the deposit until you've seen the certificate.
- Progress payments: tied to completed stages of work, or to costs backed by invoices and receipts, not to time on the job.
- Warranties: six years for major defects and two years for other defects, from completion.
Check the licence of any builder you're considering on the Service NSW licence check before you sign.
The duplex option
If you're knocking down anyway, your block may suit a duplex (dual occupancy). Since 1 July 2024, dual occupancies have been permitted in the R2 low-density residential zone across NSW, but lot size and width rules still decide whether your block qualifies.
Here's something many owners don't consider. A duplex lets you build two homes on one block. Some families live in one side and sell or rent the other to offset the build cost. Others build for multigenerational living, with parents on one side and adult kids on the other.
The rules in brief:
- As complying development: under the Low Rise Housing Diversity Code, the lot must be at least 400 m², or your council's own minimum for dual occupancies if that is larger. It must be at least 15 m wide at the building line, or 12 m if the parking is reached only from a secondary road, parallel road or lane. The code applies only where your council's planning rules already permit dual occupancies.
- Near town centres and stations: in residential zones within 800 m walk of 171 nominated centres and stations, a council can't refuse a dual occupancy DA on lot size or width if the lot is at least 450 m² and 12 m wide. That has applied since 28 February 2025.
- Pattern book designs: the NSW Housing Pattern Book includes semi-detached and dual occupancy designs endorsed by the Government Architect. Where they qualify as complying development, approval takes 10 days.
Heritage items and land with high bush fire or flood risk are excluded, and some council areas are too. To find out whether your block qualifies before you spend money on designs, talk to a builder who does this work, such as Buildana's duplex team, who can check zoning, lot size and frontage.
So which is right for you?
Renovate if the structure is sound, you mostly like the layout and your changes are focused on a few rooms. Rebuild if the house has serious structural issues, the renovation quote is creeping towards new-build pricing, or you want a layout the current house can't give you.
Do it in this order:
- Get the building and pest inspections and an asbestos assessment.
- Get a section 10.7 planning certificate, so you know which approval path your block allows.
- Get a renovation quote and a rebuild quote for the same floor area and finish.
- If you're rebuilding anyway, check whether a duplex makes sense for your block.
The order the article recommends: inspections first, then the section 10.7 planning certificate, then a renovation quote and a rebuild quote for the same floor area and finish.
Read the illustration as text
- Inspect the structure
- Building and pest inspections, plus an asbestos assessment.
- Check the planning rules
- A planning certificate shows the constraints on your block.
- Compare like for like
- A renovation quote and a rebuild quote for the same floor area.
Decide after the three checks, not before.
After the build: the clean
Whichever way you go, finish strong. Construction dust gets everywhere, and it keeps settling for days after the trades leave. Plan two cleans: the builder's clean at handover, and a home clean before you move in or hand over to tenants.
This section was added by Simply Maid.
Ask your builder what their final clean covers and get it written into the contract. Paint spots, adhesive, grout haze and site rubbish belong to that clean, not to a house cleaner.
Fine dust is the part that lingers. On a work site, SafeWork NSW's code of practice for silica dust says dry sweeping and compressed air should never be used to clean up. It calls for wet methods or an M-class or H-class vacuum, because a broom puts the dust back into the air. The same logic holds at home: damp cloths and a vacuum with a good filter, working from the top of each room down.
Once the house is handed over and the dust has had a few days to settle, a deep clean picks up what's left. Simply Maid's deep clean in Sydney includes skirting boards, door frames, ceiling fans, window sills and tracks, which is where building dust collects. For doing it yourself, see our guides to cleaning a new home before you unpack and getting rid of dust.
A home deep clean is for a finished home. It isn't a construction clean, and cleaners don't handle asbestos, lead paint or building waste.
The builder's final clean belongs in the building contract. A home deep clean a few days after handover is for the fine dust that settles once the trades have gone; it is not a construction clean.
Read the illustration as text
- The builder's clean
- Paint spots, adhesive, grout haze and site rubbish, at handover.
- The home clean
- Settled dust on skirtings, frames, fans and window tracks.
Ask what the builder's clean covers, in writing.
Questions people ask
Do I pay capital gains tax if I knock down my home and rebuild?
Usually not, if you move back in. The ATO lets you treat the land as your main residence for up to four years while you build a replacement home, as long as you move in as soon as practicable once it's finished and live there for at least three months. You can't claim another home as your main residence for the same period. A duplex where you sell or rent one side is different, so talk to your accountant first.
Do I need council approval to renovate inside my house?
Not always. Some minor renovations and low-impact building works are exempt development and need no planning approval, provided the work meets the standards in the code and the National Construction Code. The exemption doesn't apply to land on the State Heritage Register, and heritage conservation areas limit what you can do. Check the NSW Planning Portal or ask your council before you start.
About this article
Oliver Alameri, founder of Sydney builder Buildana, wrote this article as a guest. Simply Maid edited it, added the official sources and figures, and wrote the section on cleaning after the build.
Simply Maid wrote an article for Buildana's website in exchange, and no payment was made either way. The links to Buildana are to the author's own business. Simply Maid doesn't build or renovate homes.
Moving back in
Book the clean for the week you get the keys
Tell us the size of the home and when the builder hands over. A deep clean a few days after handover picks up the dust that settles once the trades have gone.
Handing over to tenants instead? See what a deep clean includes
Sources
The pages this article relies on, with the date we read each one.
- Complying development, NSW Department of Planning, Housing and Infrastructure (Updated 26 June 2026). Read 10 November 2026. What a CDC is, who issues it, the 20-day and 10-day timeframes.
- Exempt development, NSW Department of Planning, Housing and Infrastructure (Updated 23 October 2026). Read 10 November 2026. Examples of exempt work and where it cannot be carried out.
- Do I need consent from my council?, NSW Department of Planning, Housing and Infrastructure. Read 10 November 2026. What a development application is.
- Statement of Expectations Order, NSW Department of Planning, Housing and Infrastructure (Updated 2 July 2026). Read 10 November 2026. The 84-day statewide average at 31 May 2026 and the 90-day target from 1 July 2026.
- Council league table, NSW Department of Planning, Housing and Infrastructure (Updated 9 November 2026). Read 10 November 2026. Average DA assessment days by council, 2026-27 year to date, October snapshot.
- State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, NSW legislation. Read 10 November 2026. Clauses 1.17A, 1.19, 1.19A and 3.5 (land where complying development is not allowed); clause 3B.8 (dual occupancy lot size and width).
- Online section 10.7 planning certificate service, NSW Planning Portal (Last updated 14 December 2023). Read 10 November 2026. What a section 10.7 certificate shows.
- Demolition of buildings: rules for exempt and complying development, NSW Department of Planning and Environment (January 2022). Read 10 November 2026. Demolishing a dwelling under a CDC and notifying neighbours.
- Low and Mid-Rise Housing Policy, NSW Department of Planning, Housing and Infrastructure (Updated 16 July 2025). Read 10 November 2026. Dual occupancies in R2 zones from 1 July 2024; stage 2 from 28 February 2025.
- Low and Mid-Rise Housing Policy: summary of key provisions, NSW Department of Planning, Housing and Infrastructure (Updated 21 March 2025). Read 10 November 2026. The 450 m² and 12 m standards for dual occupancies near centres and stations.
- NSW Housing Pattern Book, Government Architect NSW (Updated 9 November 2026). Read 10 November 2026. The low-rise design types, including semi-detached and dual occupancy homes.
- BASIX: alterations and additions, NSW Planning Portal (Last updated 7 May 2025). Read 10 November 2026. The $50,000 threshold for renovations.
- BASIX standards, NSW Planning Portal (Last updated 10 March 2025). Read 10 November 2026. The 7-star standard from 1 October 2023 and the energy bill estimate. Exceptions apply in north-east NSW and for some apartment buildings.
- Building Activity, Australia, June 2026: average dwelling completion times, Australian Bureau of Statistics (Released 7 October 2026). Read 10 November 2026. Table 1, new houses, NSW: 2.36 quarters (2020-21), 3.39 (2023-24), 2.99 (2025-26). Months are our conversion.
- Contracts, NSW Government (Building Commission NSW) (Modified 14 May 2026). Read 10 November 2026. Contract thresholds, deposit cap, cooling-off, progress payments and home building compensation cover.
- Building defect complaints, Building Commission NSW. Read 10 November 2026. Statutory warranty periods.
- Inspection reports, NSW Government (Modified 22 September 2025). Read 10 November 2026. Who should do a building inspection and what the report leaves out. Written for buyers.
- Asbestos safety in the home, NSW Government (asbestos.nsw.gov.au). Read 10 November 2026. Home ages likely to contain asbestos. The planning department's pages use 1987 for the same warning.
- Unlicensed asbestos removal, NSW Government (asbestos.nsw.gov.au). Read 10 November 2026. When a licensed asbestos removalist is required.
- Indoor air quality, Australian Government, YourHome (Updated 2020). Read 10 November 2026. Lead paint in homes built before 1970.
- Engineered stone code of practice: clean-up and disposal of silica dust, SafeWork NSW. Read 10 November 2026. Dry sweeping and vacuum classes. A workplace code for trades, not advice written for householders.
- Building or renovating your home, Australian Taxation Office (Last updated 22 June 2026). Read 10 November 2026. The four-year main residence rule.
- Knock down rebuild cost Sydney 2026, Buildana (the author's business) (Published 14 April 2026, modified 8 November 2026). Read 10 November 2026. The author's own knockdown rebuild estimates.
- How much does a home renovation cost in Sydney? 2026 price guide, Buildana (the author's business) (25 March 2026). Read 10 November 2026. The author's own renovation and extension estimates.
- Construction cost table, 2026, BMT Tax Depreciation Quantity Surveyors. Read 10 November 2026. Sydney, four-bedroom brick veneer two-level house, low to high finish, excluding GST.
- Deep cleaning, Simply Maid. Read 10 November 2026. What Simply Maid's deep clean includes.
General information, not building, legal or financial advice. Planning rules and costs change; check the official source and get advice for your own property before you act.