Guide · Home construction · Wollongong

Is $400,000 enough to build a house in Wollongong?

On land you already own, yes — for a modest home on a straightforward block. As a budget to buy land and build, no. The difference is arithmetic you can check yourself, and most of it sits outside the building contract.

By Keiron Moore, Founder and Managing Director, CKS Projects Published 28 September 2026 Updated 28 September 2026 14 min read

$565,749average cost to construct a detached house in NSW, 2024/25
$2,396average per square metre, NSW detached house, 2024/25
10%maximum deposit under the Home Building Act 1989
6 / 2years of statutory warranty — major defects / other defects

Construction figures: Master Builders Association of NSW, 26 May 2026, from ABS data. Warranty and deposit figures: Home Building Act 1989 (NSW). Sources are listed at the end of this page. These are state-wide averages and legal limits — not a price for your build.

The short answer

There are two different questions hiding inside “$400,000”, and they have different answers.

If you already own the land — a block you have held, a subdivision behind your house, or an existing home you are knocking down and rebuilding on — then $400,000 is a genuine construction budget. It will not build a large home, and it will not build anything that needs substantial earthworks, retaining or engineered footings. It can build a modest, well-detailed house on a flat, well-serviced block, provided $400,000 is your whole budget and not just the contract price.

If you still have to buy the land, then no. In 2026, $400,000 will not buy land and build a house in Wollongong, and the gap is not marginal. Master Builders Association of NSW reports that the average cost of constructing a detached house in NSW was $565,749 in 2024/25, or $2,396.23 per square metre. That is construction only. Land, transfer duty, site costs, consultants, approvals, connections and external works all sit on top of it.

The rest of this page is about that second sentence: what sits on top, how large it gets, and how you find out before you are committed rather than at contract stage.

What $400,000 actually has to cover

A build price is one layer of a stack. Most budget blowouts I see are not the builder's price rising — they are layers nobody counted at the start. Here they are in the order they hit you.

The cost layers of a new home
Layer	What it covers	Where budgets lose it
Land and duty	The block, plus NSW transfer duty unless you qualify for an exemption or concession.	Assuming duty is a rounding error. Under the First Home Buyer Assistance Scheme, vacant land gets a full exemption at or below $350,000 and a concessional rate above $350,000 and below $450,000 — so a $400,000 lot sits in the concessional band, not the exempt one. The First Home Owner Grant (New Homes) is $10,000, and where you buy land and sign a comprehensive home building contract the combined land value, contract value and variations must not exceed $750,000.
Building contract	The house: structure, envelope, linings, wet areas, and the inclusions listed in the specification.	Comparing contract prices without comparing inclusions. Two contracts for the same floor area can differ by six figures because of what each excludes.
Site costs	Getting a level, stable, drained platform: earthworks, rock, fill compaction, retaining, engineered footings, temporary works.	Treating it as a provisional sum. On a sloping or wet Illawarra block it is frequently the largest single variance in the job.
Design and consultants	Architect or building designer, structural engineer, geotechnical report, survey, BASIX assessment, bushfire assessment, certifier.	Starting design before the ground is understood. On a difficult site, redesign after the geotech arrives costs more than the reports ever did.
Approvals and levies	DA or CDC fees, construction certificate, the long service levy, council development contributions.	Timing. The long service levy must be paid before the construction or complying development certificate is released, so unpaid levies delay a start date.
Connections	Water, sewer, stormwater, electricity, telecommunications — and Sydney Water's compliance and infrastructure charges.	Assuming a gravity sewer connection. Where the main sits low or the block falls away from it, you are looking at a pumped system.
External works	Driveway, crossover, fencing, retaining to boundaries, landscaping, letterbox, clothesline, external taps.	Leaving it out entirely. A house is not habitable in practice without a driveway and fencing, and these are commonly excluded from the contract.
Insurance and holding costs	Home Building Compensation Fund premium, construction and public liability cover, rent or interest while you build.	Forgetting that you may be paying a mortgage and rent at the same time for twelve to eighteen months.
Contingency	The money you have not spent yet on the things you cannot see yet.	Setting it at zero. A contingency that gets spent is not a failure; a build with no contingency is.

The one number worth checking yourself

On 26 May 2026, Master Builders Association of NSW published average construction costs drawn from ABS data. For a detached house in NSW, it reported $565,749 for 2024/25, up from $276,522 in 2007/08 — nearly $300,000 of increase in eighteen years — and $2,396.23 per square metre.

Use that number, but understand what it is. Three caveats matter:

It is an average, not a price. It blends project homes and custom homes, small and large, flat and difficult sites. Individual builds sit either side of it, often by a wide margin.
It is construction only. Land, duty, external works and holding costs are not in it.
Per-square-metre rates hide the biggest local variable. In the Illawarra that variable is the ground. Two blocks with identical houses on them can have site costs that differ by more than the difference between their floor areas.

Do the arithmetic honestly and it is sobering. At the NSW average of $2,396.23 per square metre, $400,000 of construction buys roughly 167 m² — about a three-bedroom home — and that is before any site cost, driveway, landscaping or approval fee. So the real question is not “how many square metres can $400,000 buy”, it is “how much of my $400,000 survives contact with my block”.

Why two quotes for the same house can differ by six figures

This is where I would concentrate if you are testing a $400,000 budget. A quote is not a price until you know what it excludes.

A low number is often achieved by moving risk out of the contract and into allowances — provisional sums for site works, prime cost items for fixtures, and an inclusions list that stops short of the driveway, the retaining and the landscaping. Those allowances are legitimate when the scope genuinely cannot be priced yet. They become a problem when they are used to make a number look affordable, because the money comes back later as variations.

NSW law gives you some protection here, and it is worth knowing what it does and does not do. Under the Home Building Act 1989, a contract must state the price where it is known, and where the price is not known or may vary, the contract must carry a warning and an explanation next to the price (section 7). Variations have to be in writing, signed by both parties, and form part of the contract — and the guidance from NSW Fair Trading is that the cost calculation should be shown, not just a dollar figure.

Four questions to ask any quote

What is excluded? Ask for the list in writing, not a summary.
Is the site cost a fixed amount or an allowance? If it is an allowance, what was it based on, and who carries the risk if the ground is worse?
What is the specification behind the rate? Fixtures, glazing, insulation, floor coverings, painting, external works.
Who priced the design? A quote against an unresolved design is an estimate dressed up as a number.

This is the reason CKS Projects works in a fixed order — ground, design, price, build — and quotes one fixed number once the design and the site are resolved. A price produced before the ground is known is not a price.

Site costs are what decide whether $400,000 works at all

“Site costs” is an unglamorous phrase for a simple job: getting a level, stable, drained platform to build on. On a flat, cleared, well-serviced suburban block it is modest. On the blocks I am usually asked about, it is not.

The things that move the number in the Illawarra:

Slope, and which way it falls. A block falling away from the road pushes spoil, materials and services uphill. Cut-and-fill balance matters more than the total fall.
Cut versus fill. Natural ground can generally be built on once it is proven. Fill has to be placed and compacted in controlled layers and tested, or the footing design has to bridge it.
Rock. Illawarra sandstone does not excavate like soil. It is sawn, split or hammered, and the spoil has to go somewhere.
Water. A high water table, springs or seepage at a rock-shale contact changes drainage, waterproofing and footing design. It is also the thing most likely to have been missed by a design drawn from a contour map.
Retaining. Retaining near a boundary is engineered, sometimes fire-rated, always expensive, and it is frequently excluded from build contracts.
Access. Can a truck, a concrete pump and, on a steep site, a crane actually get where they need to be? Restricted access turns a normal pour into a slow one.
Bushfire. A higher Bushfire Attack Level can require specific glazing, seals, screens and materials, which is a construction cost, not just an approval cost.
Mining history. Parts of the Illawarra sit above historic coal workings. If your land is in a declared mine subsidence district, check early with Subsidence Advisory NSW what approval is needed and how it affects footing design.

Anyone who can give you a site-cost percentage without seeing the block has not priced your job. What I can tell you is that on a steep or wet site, site costs stop being a line item and become the project.

You can see what that means in practice in the Illawarra Escarpment guide, and on the Wombarra Clifftops build, where the site sat in an escarpment slip zone with water running beneath it.

What $400,000 can genuinely do

If $400,000 is your ceiling, these are the routes I would actually discuss with you. All of them depend on your property, your zoning and your finances, and none of them is a promise.

Build on land you already own. The single biggest lever. Removing land and duty from the equation is what makes $400,000 a workable construction budget at all.
Reduce floor area, not specification of the essentials. Smaller and simpler beats larger and cheaper. A compact plan with a straightforward roof form, standard window sizes and a wet area concentrated in one place costs meaningfully less than a sprawling one with the same finishes. Cut scope in this order: area, complexity, then finishes. Do not cut drainage, footings, fire separation or waterproofing.
Build the secondary dwelling first. A secondary dwelling is a different product with a different approval pathway and a much smaller budget than a house. It is not a duplex and it cannot be sold separately — this page explains the difference — but as a first step on a larger block it is a route people take.
Consider two dwellings where the lot allows. A duplex or dual occupancy spreads land cost across two incomes or two titles. It also brings two sets of approvals, contributions and connections, so the numbers need to be tested, not assumed. Start with the minimum lot size rules for Wollongong.
Look at the land market next door. CKS Projects builds across the Illawarra, Shellharbour, Kiama, the Shoalhaven and the Southern Highlands. The same budget buys very different land in Wollongong and in the Shoalhaven, and the builder's cost base does not change as much as the land price does.

BASIX and the 7-star standard now shape your specification

Energy compliance is not a paperwork exercise any more; it changes what you buy. Increases to the BASIX standards took effect on 1 October 2023, introduced through the State Environmental Planning Policy (Sustainable Buildings) 2022, with a twelve-month transition for applicants who had signed a building contract before that date which ended on 30 September 2024.

For a detached or attached house, the thermal performance requirement moved from heating and cooling caps delivering an average 5.5–6 NatHERS stars to 7 NatHERS stars, with revised heating and cooling caps, to align with the National Construction Code 2022. Energy standards now vary with total floor area, and a new materials index calculates and reports the embodied emissions of the home — with no limit set on it at present.

One detail lands squarely on this region. Under the DIY method, dark roofs — solar absorptance greater than 0.7 — cannot be selected for developments in coastal areas north of Wollongong, including Greater Sydney, and inland west of the Great Dividing Range. Wollongong is effectively the line on that map. The simulation method and the Passive House pathway can still model a dark roof, and where a dark roof is allowable, other specifications usually have to improve to compensate.

A BASIX certificate is required for a new home and for renovations of $50,000 or more. The published maximum fee for a single dwelling is $50, plus a $5 NSW Planning Portal fee. Budget-wise, the real cost is not the certificate — it is the glazing, insulation, sealing and orientation needed to pass it, which is cheaper to design in than to retrofit.

The rules that protect a $400,000 contract

At this budget you are inside every consumer protection in the Home Building Act 1989 (NSW). These are the ones I would check before signing anything, with anyone.

Home Building Act 1989 (NSW) — what applies to a new home contract
Requirement	What the law says	Section
Written contract	Required for residential building work over $5,000 including GST. Work between $5,000 and $20,000 is a small job; over $20,000 is a large job with fuller prescribed contents.	s 7, s 7AAA
Consumer Building Guide	Must be given to the owner before entering a contract for work over $5,000, along with the prescribed checklist and the owner's acknowledgement.	s 7AAA
Maximum deposit	Ten per cent of the contract price.	s 8(1)
Cooling-off period	Five clear business days for contracts over $20,000. It can only be waived by a certificate from a solicitor independent of the builder. If the required cooling-off statement was not in the contract, the owner may rescind within seven days of becoming aware of that.	s 7BA, s 7BB(2)
Copy of the contract	The contractor must give the owner a signed copy within five clear business days of entering the contract.	s 7B
Insurance	Home Building Compensation Fund cover is required for residential building work over $20,000. The principal contractor must take it out, and it must be in force before work starts and before any payment is taken, including the deposit.	Part 6
Progress payments	Must match the work carried out. Authorised forms are a fixed amount or percentage on completion of a described stage, payment for labour and materials already incurred supported by invoices or receipts, or a combination.	s 8A(2)
Variations	In writing, signed by both parties, attached to and forming part of the contract, with the cost implications and the calculation explained.	s 7(2), s 7(5)
Statutory warranties	Six years where the breach results in a major defect, two years in any other case, running from completion of the work.	s 18B, s 18E
Security of Payment Guide	Since 26 June 2021, an owner-occupier contract over $20,000 must include the Security of Payment Guide.	Building and Construction Industry Security of Payment Act 1999

Summarised for homeowners, not legal advice. Check the current text with NSW Fair Trading or a solicitor before you rely on it — the Act and its Regulation change.

Fees, levies and charges people forget

Long Service Payments Levy. 0.25% of the cost of building and construction works of $250,000 or more including GST, paid to the Long Service Corporation. On a $400,000 contract that is $1,000. It matters for your start date as much as your budget: a council or certifier can only release a construction certificate or complying development certificate after the levy is paid. (Before 1 January 2023 the rate was 0.35% on works of $25,000 and above.)
DA and construction certificate fees. Set by Schedule 4 of the Environmental Planning and Assessment Regulation 2021 and calculated on the estimated cost of development in fee units, indexed each 1 July. The fee unit for 2026/27 is $118.55. Confirm the current figure for your development with Wollongong City Council.
Development contributions. Wollongong levies contributions under section 7.12 through its City-Wide Development Contributions Plan, proportional to the proposed cost of development. The 2025 plan, in force from 8 December 2025, sets nil up to $100,000, 0.5% between $100,000 and $200,000, and 1% above $200,000. These plans are replaced and re-indexed regularly, so check the current one before you budget. Note also that where a section 7.11 contribution was already paid at subdivision and the development does not increase demand, a section 7.12 contribution cannot be levied — and that inside the West Dapto Urban Release Area a separate plan levies per additional lot or dwelling instead of as a percentage.
Sydney Water. A Section 73 Compliance Certificate is part of the approval process, and infrastructure contributions may apply, calculated by a method determined by IPART and adjusted for CPI each 1 July. The Illawarra is covered by its own drinking water and wastewater development servicing plans, so the charge here is not the same as in Sydney.
BASIX. Certificate required for a new home; maximum fee $50 for a single dwelling plus the $5 portal fee.
Independent progress inspections. If you want them, NSW guidance puts an independent progress inspection at $250 to $500 each. On a build where you are not on site, they are cheap insurance.

How I would answer this for your block

I cannot answer “is $400,000 enough” honestly from a floor plan. The answer lives in the ground, the zoning, the access and the specification, in that order.

What I do instead is spend 45 minutes on your site, and I do it myself rather than sending a sales representative. I look at slope, frontage, access, zoning and water. Then I tell you what the block will carry, what a realistic budget range is for what you want on it, and whether your brief and your budget are pointing at the same house. Sometimes the honest answer is “not on this block, not at this budget”, and I would rather say that in week one than discover it in month nine.

If the numbers do work, CKS Projects prices from the resolved design and the site assessment and issues one fixed number. No provisional sums used to win the job and recovered later in variations. We take a limited number of builds at a time so I stay close to each one.

What to bring to the assessment

Your deposit number and your whole budget — including land, duty, fees, external works and holding costs, not just construction.
The block: address, lot and DP number, and any survey, contour or drainage plan you already have.
Any plans or inspiration, and be clear about which parts are non-negotiable.
Your target date to be living in it, and where you will live during the build.

Building a home on the Illawarra Escarpment

Ground, slope, water, access and bushfire — what changes when the block is on the escarpment rather than behind it.

What is a DualOcc?

Dual occupancy, secondary dwellings, duplexes and titles: the definitions and the differences that change what you can build.

Minimum land size for a duplex in Wollongong

The lot size, frontage and zone controls that decide whether two dwellings fit, and whether they can be two titles.

Sources

Every figure on this page comes from one of the following, checked on 28 September 2026. Where a number could not be verified against a primary source, it has been left out.

Master Builders Association of NSW, Average costs of building Australian homes, 26 May 2026 — NSW average detached house construction cost $565,749 and $2,396.23 per square metre for 2024/25; 2007/08 comparator $276,522.
NSW Government, Contracts for residential building work — Home Building Act 1989 (NSW) contract requirements, deposit cap, cooling-off period, progress payments and statutory warranties.
NSW Government, Home building contract checklist — Consumer Building Guide and the prescribed pre-contract checklist.
Legal Aid NSW, Builders and contractors — the Security of Payment Guide requirement for owner-occupier contracts over $20,000.
icare, Do I need HBCF? — Home Building Compensation Fund threshold and who must insure.
NSW Planning Portal, Increase to BASIX Standards, last updated 10 March 2025 — 7 NatHERS stars for detached and attached houses from 1 October 2023, materials index, and the dark-roof DIY restriction for coastal areas north of Wollongong.
NSW Planning Portal, BASIX — when a certificate is required.
NSW Department of Planning, What is the fee for a BASIX certificate? — fee schedule including the $5 portal fee.
NSW Government / Long Service Corporation, Long service levy for the building and construction industry — 0.25% on works of $250,000 or more, and the requirement to pay before a CC or CDC is released.
NSW Department of Planning, Planning and development fees — 2026/27 fee unit of $118.55 under the Environmental Planning and Assessment Regulation 2021.
Revenue NSW, First Home Buyer Assistance Scheme — duty exemption and concession thresholds for new and existing homes and for vacant land.
Revenue NSW, First Home Owner Grant (New Homes) — $10,000 grant and the $600,000 and $750,000 price caps.
Sydney Water, Land development — Section 73 Compliance Certificate and IPART-determined infrastructure contributions.
Wollongong City Council, Development contributions — the City-Wide Development Contributions Plan (2025) section 7.12 rates, and the West Dapto Development Contributions Plan (2025).

This page is general information written by a builder for homeowners. It is not financial, legal, tax or town-planning advice, and requirements change. Fees, thresholds and contribution rates should be confirmed with the relevant authority before you commit money. Figures are current as at 28 September 2026.

Keiron Moore, Founder and Managing Director of CKS Projects