What is the difference between budget, standard and prestige build quality?

Budget quality uses volume builder inclusions -- standard floor tiles, laminate benchtops, basic fixtures, minimal design customisation. Standard quality adds engineered stone benchtops, quality tapware, timber flooring in living areas and more design flexibility. Mid quality moves to fully custom design, premium appliances, stone or hardwood floors throughout and high-specification joinery. Prestige quality uses architect-designed bespoke finishes, imported materials, smart-home systems and structural elements beyond the standard.

Why do extensions cost more per m2 than new builds?

Extensions involve working within or adjacent to an existing occupied structure, which creates several cost premiums: difficult access for materials and equipment, careful protection of existing finishes and structure, the complexity of tying in new work to existing rooflines and footings, and typically smaller volumes with more custom work per unit area. A new build benefits from scale, clear access and a clean slate -- extensions have none of these advantages.

How accurate is a cost-per-m2 estimate for a finance application?

Cost-per-m2 benchmarks are useful for early feasibility and budget-setting but are not sufficiently accurate for formal construction loan applications. Lenders typically require a fixed-price builder contract or a formal quantity surveyor's report (Section 11 report) for construction finance. Commission a QS if your project is at the finance stage.

Build Cost Estimator — Free Construction Calculator

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A client wants a 4-bedroom single-storey house on a flat suburban block in Brisbane. Before the architect is engaged, they need a ballpark build cost to confirm the project is within budget and secure the construction loan pre-approval.

Build Cost Estimator

Budget

Floor area (m²)

Total internal floor area

Build quality

Build type

Location

AU cost per m² (approx, metro, 2024–25):
Budget: $1,500–$1,900/m² · Standard: $2,000–$2,800/m² · Mid-range: $2,800–$3,800/m² · Prestige: $3,800–$6,000+/m²
Double-storey adds ~10–15% per m². Extensions typically cost 20–30% more per m² than new builds due to tie-in complexity.
Not included: Land, site costs (slab, retaining, drainage), council fees, landscaping, driveway, fencing.

Reference: Rawlinsons Australian Construction Handbook

ℹ️ Results are estimates for planning purposes. Verify with current standards and a qualified professional.

1 What this calculator does

Estimates the total build cost for a new house, double-storey home, unit, extension or renovation from floor area, quality level and location. Uses 2024-25 Australian industry cost-per-m2 benchmarks. Applies a location multiplier for regional vs metro areas. Excludes land, site preparation, council fees and landscaping.

2 Formula & professional reasoning

Build cost = Floor area (m2) x Rate per m2 x Location multiplier
AU rates per m2 (metro 2024-25 approx):
  House: Budget $1,700 | Standard $2,400 | Mid $3,300 | Prestige $5,000
  Double storey: Budget $1,900 | Standard $2,700 | Mid $3,700 | Prestige $5,500
  Unit/townhouse: Budget $1,600 | Standard $2,200 | Mid $3,000 | Prestige $4,500
  Extension: Budget $2,100 | Standard $3,000 | Mid $4,000 | Prestige $6,000
Location multipliers: Metro 1.0 | Regional 1.05-1.15 | Remote 1.20-1.35

Build cost per m2 benchmarks are derived from published industry data (HIA, Rawlinsons) and reflect typical contract prices for each quality tier. Budget quality uses volume builder inclusions and standard materials. Prestige quality uses architect-designed custom finishes, premium materials and bespoke joinery. Extensions and renovations cost more per m2 than new builds because of the complexity of working within an existing structure -- difficult access, protection of existing work and higher labour rates per unit of output. The location multiplier reflects higher labour and material transport costs in regional and remote areas.

3 Worked examples

⚠️ Illustrative example only — not clinical or professional instruction.

Basic

Standard single-storey house in Brisbane

Given: Floor area: 220 m2 | Type: house | Quality: standard | Location: metro (1.0x)

Working: Rate: $2,400/m2 x 1.0 = $2,400/m2 | Build cost: 220 x $2,400 = $528,000

Answer: Estimated build cost: $528,000

💡 Excludes land ($300K-$600K in suburban Brisbane), site preparation ($10K-$30K), council fees ($15K-$25K), landscaping and driveway ($15K-$40K). Add 10-15% contingency: total project budget $620K-$670K.

Standard

Double-storey mid-quality build in Sydney

Given: Floor area: 310 m2 | Type: double storey | Quality: mid | Location: metro (1.0x)

Working: Rate: $3,700/m2 | Build cost: 310 x $3,700 = $1,147,000

Answer: Estimated build cost: $1,147,000

💡 A 310 m2 double-storey at mid quality is a substantial family home. With land, fees and landscaping the total project cost could exceed $1.6M-$1.9M in Sydney. Confirm with a quantity surveyor for finance purposes.

Advanced

Regional extension with location premium

Given: Floor area: 65 m2 | Type: extension | Quality: standard | Location: regional (1.12x)

Working: Rate: $3,000 x 1.12 = $3,360/m2 | Build cost: 65 x $3,360 = $218,400

Answer: Estimated build cost: $218,400

💡 A 65 m2 extension at standard quality costs $218K in a regional area -- 12% more than metro due to labour and material transport costs. Extensions typically cost more per m2 than new builds; access restrictions, tie-ins to existing structure and protection of the occupied home all add cost.

4 Sanity check

AU build cost per m2 cross-check (2024-25)

Budget house: $1,700-$2,000/m2 | Standard house: $2,200-$2,600/m2 | Prestige: $4,500-$6,000+/m2

Source: HIA Cost of Construction Report, Rawlinsons Australian Construction Handbook 2024.

What is NOT included

Add these separately -- they can add 30-50% to the build cost for new homes.

Always add contingency

New builds: 10-15% contingency | Renovations and extensions: 15-20% contingency

Unforeseen site conditions, material cost increases and design changes are normal on construction projects.

Get 3 builder quotes

Cost-per-m2 benchmarks vary +/-20% between builders for the same spec | Always obtain at least 3 detailed quotes from licensed builders

5 Common errors

Error	Cause	Consequence	Fix
Using the build cost as the total project budget	Treating the construction contract price as the only cost	Significant budget shortfall at land purchase, during construction or at practical completion	Add land cost, site preparation, DA/CC fees (1-2% of build cost), architect and engineer fees (3-8%), landscaping, driveway, fencing, furniture and a 10-15% contingency to arrive at the total project budget.
Not adjusting for quality level when comparing quotes	Comparing a volume builder (budget spec) quote to a custom builder (prestige spec) quote on a per-m2 basis	Appears cheaper but delivers a lower-specification home -- cost overruns when upgrading specifications	Ensure quotes are like-for-like with the same inclusions list. A volume builder at $2,000/m2 with minimal inclusions may deliver less value than a custom builder at $2,600/m2 with high-quality fixtures and finishes.
Not accounting for site-specific costs	Using a flat-site benchmark rate on a sloping or difficult site	Build cost understated by $20,000-$100,000+ for steep or constrained sites	Sloping sites require additional excavation, retaining walls, piling or post-and-beam substructure. A slope of more than 1 in 10 typically adds $20,000-$50,000 to the base build cost. Commission a preliminary site assessment before using benchmark rates.
Not verifying the builder's licence before signing a contract	Assuming all builders are licensed	Unlicensed builder work is not covered by home warranty insurance -- significant financial and legal risk	Verify the builder's licence number through your state licensing authority (QBCC in QLD, Service NSW, VBA in VIC) before signing any building contract.