Total Build Cost Summary
These ranges are based on a typical 200-250m² single-storey knockdown rebuild in a metro area of Sydney, Melbourne, or Brisbane. Regional builds are typically 10-20% cheaper. Two-storey builds add 30-50% to frame, slab, and cladding costs.
| Stage | Low | Mid | High |
|---|
| Demolition | $15,000 | $25,000 | $45,000 |
| Pre-construction fees | $8,000 | $15,000 | $25,000 |
| Site preparation | $5,000 | $12,000 | $30,000 |
| Slab / foundations | $20,000 | $35,000 | $55,000 |
| Framing | $35,000 | $55,000 | $80,000 |
| Roofing | $10,000 | $18,000 | $30,000 |
| Brickwork / cladding | $15,000 | $28,000 | $50,000 |
| Windows and doors | $12,000 | $22,000 | $40,000 |
| Plumbing | $15,000 | $25,000 | $40,000 |
| Electrical | $10,000 | $18,000 | $30,000 |
| Insulation and plasterboard | $8,000 | $14,000 | $22,000 |
| Tiling and waterproofing | $8,000 | $15,000 | $28,000 |
| Cabinetry and joinery | $12,000 | $25,000 | $50,000 |
| Painting | $6,000 | $12,000 | $20,000 |
| Fixtures and fittings | $8,000 | $15,000 | $30,000 |
| Landscaping and external | $10,000 | $25,000 | $60,000 |
| TOTAL (excl. contingency) | $197,000 | $359,000 | $635,000 |
| Contingency (10-15%) | $20,000 | $45,000 | $95,000 |
| TOTAL (incl. contingency) | $217,000 | $404,000 | $730,000 |
Tip:These are owner-builder costs (you managing trades directly). Using a licensed builder typically adds 20-35% margin on top. That margin is your potential saving -- but you earn it through project management effort.
1. Demolition Costs
The first major cost in any knockdown rebuild. Prices vary based on house size, asbestos presence, site access, and whether you need to disconnect services.
| Line Item | Low | Mid | High | Notes |
|---|
| Demolition (single storey, no asbestos) | $12,000 | $18,000 | $25,000 | Includes site cleanup and waste removal |
| Demolition (with asbestos) | $18,000 | $30,000 | $45,000 | Licensed asbestos removal adds $5-15K |
| Service disconnections (power, gas, water, sewer) | $1,500 | $3,000 | $5,000 | Apply 4-6 weeks before demo |
| Tree removal (per large tree) | $800 | $2,000 | $5,000 | Protected trees need council approval |
| Council demolition notification | $200 | $500 | $1,000 | Some councils charge, some don't |
2. Pre-Construction Fees
Professional fees and permits. These are fixed costs that don't scale with house size -- a $300K build pays the same architect fees as a $600K build.
| Line Item | Low | Mid | High | Notes |
|---|
| Architectural / drafting | $3,000 | $6,000 | $15,000 | Basic drafting vs full architectural design |
| Structural engineering | $2,000 | $4,000 | $8,000 | Complex sites (slope, reactive soil) cost more |
| Soil / geotech report | $400 | $800 | $1,500 | Essential -- determines your slab type |
| Surveyor (boundary + contour) | $600 | $1,200 | $2,000 | Required before DA/CDC lodgement |
| Energy efficiency report | $300 | $600 | $1,200 | NatHERS or BASIX (NSW) assessment |
| Council DA / CDC fees | $1,000 | $3,000 | $8,000 | CDC is cheaper and faster than DA |
| Owner-builder permit | $100 | $300 | $800 | Varies by state -- check your state guide |
Tip:These fees are non-negotiable and must be paid regardless of your build size. Budget $15K minimum for professional fees on any knockdown rebuild.
3. Site Preparation
| Line Item | Low | Mid | High | Notes |
|---|
| Site cut / earthworks | $2,000 | $5,000 | $15,000 | Flat sites are cheapest; sloped sites need retaining |
| Temporary fencing | $800 | $1,500 | $3,000 | Council requirement -- 1.8m high minimum |
| Portaloo hire (6-12 months) | $1,200 | $2,400 | $3,600 | Budget $200-300/month |
| Skip bins (entire build) | $2,000 | $4,000 | $8,000 | Budget 8-12 skips across the full build |
| Temporary power connection | $500 | $1,500 | $3,000 | Apply through your local distributor |
4. Slab and Foundations
Slab cost per square metre ranges from $90-$220/m² depending on soil type, slab design (waffle pod vs raft), and reinforcement requirements.
| Line Item | Low | Mid | High | Notes |
|---|
| Concrete slab (waffle pod, 200m²) | $18,000 | $28,000 | $40,000 | $90-200/m² depending on soil class |
| Reinforcement (reo mesh + bar) | Incl. | Incl. | Incl. | Included in slab quote typically |
| Under-slab plumbing rough-in | $2,000 | $4,000 | $7,000 | More bathrooms = higher cost |
| Termite barrier | $1,500 | $3,000 | $5,000 | Physical or chemical -- required by BCA |
| Waterproof membrane | $500 | $1,000 | $2,000 | Under-slab moisture barrier |
| Concrete pump hire | $800 | $1,200 | $2,000 | Required if truck can't reach the pour area |
5. Framing
Framing is the single biggest trade cost on most builds. Per-square-metre costs range from $150-$350/m² for supply and install including trusses.
| Line Item | Low | Mid | High | Notes |
|---|
| Wall frames (supply + install) | $15,000 | $25,000 | $35,000 | Timber frame standard; steel adds 20-30% |
| Roof trusses (supply + install) | $12,000 | $20,000 | $30,000 | Engineered trusses -- never modify on-site |
| Structural steel (lintels, beams, posts) | $3,000 | $6,000 | $12,000 | Large openings need steel -- cost adds up fast |
| Scaffolding hire | $2,000 | $4,000 | $8,000 | Required from frame through to external paint |
| Crane hire (truss lift) | $1,000 | $2,000 | $4,000 | Single lift day for most standard homes |
6. Roofing
| Line Item | Low | Mid | High | Notes |
|---|
| Roof sheeting (Colorbond) | $6,000 | $10,000 | $16,000 | Metal is standard; tiles add 30-50% |
| Roof tiles (if applicable) | $10,000 | $16,000 | $25,000 | Concrete tiles cheaper than terracotta |
| Fascia and guttering | $2,000 | $4,000 | $7,000 | Colorbond to match roof colour |
| Downpipes and stormwater connection | $1,000 | $2,000 | $4,000 | Must connect to council stormwater |
| Roof sarking / underlay | $800 | $1,500 | $3,000 | Required by BCA for condensation control |
7. Brickwork and Cladding
| Line Item | Low | Mid | High | Notes |
|---|
| Face brickwork (supply + lay) | $12,000 | $22,000 | $38,000 | Price varies hugely by brick selection |
| External cladding (weatherboard, James Hardie) | $8,000 | $15,000 | $28,000 | Often cheaper than full brick |
| Render / texture coat | $5,000 | $10,000 | $18,000 | Applied over blockwork or foam panels |
| Wall wrapping / sarking | $1,000 | $2,000 | $4,000 | Required under all cladding types |
8. Windows and Doors
| Line Item | Low | Mid | High | Notes |
|---|
| Aluminium windows (supply + install) | $8,000 | $14,000 | $22,000 | Standard aluminium frames |
| Timber or uPVC windows | $12,000 | $20,000 | $35,000 | Premium option, better thermal performance |
| Sliding / bi-fold doors | $3,000 | $6,000 | $15,000 | Price depends heavily on width and type |
| External doors (entry + laundry) | $1,500 | $3,000 | $6,000 | Solid core for security |
| Internal doors (supply + install) | $2,000 | $4,000 | $8,000 | Budget $200-600 per door installed |
| Garage door (single / double) | $1,500 | $3,000 | $6,000 | Sectional is standard; tilt-a-door is cheaper |
9-15. Remaining Trade Costs
Here are the remaining trades in summary. Each follows the same pattern -- get 3 quotes, verify scope, and track against these benchmarks.
| Trade | Low | Mid | High | Key Notes |
|---|
| Plumbing (rough-in + fit-off) | $15,000 | $25,000 | $40,000 | More wet areas = higher cost |
| Electrical (rough-in + fit-off) | $10,000 | $18,000 | $30,000 | LED downlights standard; pendants extra |
| Insulation + plasterboard | $8,000 | $14,000 | $22,000 | Insulation R-values set by energy report |
| Tiling + waterproofing | $8,000 | $15,000 | $28,000 | Waterproofing certification mandatory |
| Cabinetry + joinery | $12,000 | $25,000 | $50,000 | Kitchen is 60-70% of this category |
| Painting (internal + external) | $6,000 | $12,000 | $20,000 | 3 coats minimum: 1 primer + 2 finish |
| Fixtures + fittings | $8,000 | $15,000 | $30,000 | Tapware, toilets, basins, lights, appliances |
| Landscaping + external | $10,000 | $25,000 | $60,000 | Driveway, fencing, turf, paths, outdoor area |
Cost Per Square Metre Summary
These per-m² benchmarks help you quickly sense-check quotes. If a trade quote is significantly above the "High" range, ask why -- or get more quotes.
| Build Element | Low $/m² | Mid $/m² | High $/m² |
|---|
| Slab (waffle pod) | $90 | $140 | $220 |
| Framing (supply + install) | $150 | $240 | $350 |
| Roofing (Colorbond) | $45 | $70 | $110 |
| Brickwork (full brick) | $60 | $100 | $170 |
| Overall build cost | $985 | $1,600 | $2,900 |
Tip:The overall $/m² range of $985-$2,900 reflects the massive difference between a basic spec build and a high-end architectural home. Most owner-builders land in the $1,400-$2,000/m² range for a well-specified family home.
Costs Most Owner-Builders Forget
These are the line items that blow budgets because nobody told you about them upfront.
| Hidden Cost | Typical Range | Why It Gets Missed |
|---|
| Temporary power connection | $500 - $3,000 | Assumed to be included in electrical quote |
| Stormwater connection to council | $1,500 - $5,000 | Often not in the plumber's scope |
| Driveway crossover (new kerb cut) | $1,000 - $4,000 | Council charges for modifying the kerb |
| Soil compaction testing | $500 - $2,000 | Required on fill sites before slab pour |
| Scaffolding (6+ months) | $3,000 - $8,000 | Hired per month -- builds always take longer |
| Service relocations (power pole, sewer) | $2,000 - $15,000 | Only discovered at site prep stage |
| Letterbox, clothesline, TV antenna | $500 - $2,000 | Genuinely forgotten on almost every build |
| Final clean (professional) | $500 - $1,500 | Required before your OC inspection |