Estimate your NZ residential build cost — Simple or Professional mode
Estimated total project cost
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Step 1 of 7
Where in New Zealand are you building?
Building costs vary significantly by region.
What kind of project is this?
Each type has different cost characteristics.
How big is your home?
Floor area is the total internal floor space. Don't know the m²? Use the bedroom guide below.
50 m²160 m²500 m²
Studio3-bed homeLarge homeMansion
Not sure of the size? Pick by bedrooms:
What kind of finish are you looking for?
Read the descriptions and pick what matches your vision.
What is your site like?
Difficult sites cost more to build on. Be honest — this affects your estimate significantly.
Any big extras to include?
Tick everything you plan to have. These add directly to your estimate.
When do you expect to start building?
Building costs rise over time. We'll adjust your estimate for construction price inflation (using Stats NZ CGPI, not general CPI).
We assume 4% per year construction cost inflation. If you start later, your out-turn cost will be higher than today's dollars.
Your estimated build cost
Low
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Expected
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High
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Low
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Expected
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High
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What's included in this estimate
Not included
Estimates based on Rawlinsons NZ Construction Handbook 2024–25, adjusted for realistic contractor pricing. Incl. GST. Does not include land. Always get at least 3 quotes from licensed building practitioners (LBPs).
Project basics
160 m²
Specification level
Structural upgrades (delta from quality baseline)
Kitchen joinery (delta from quality baseline — appliances separate below)
The base rate includes kitchen joinery and cabinetry only. Appliances (oven, cooktop, dishwasher, etc.) are listed separately below and are not double-counted.
1
Bathrooms (delta from quality baseline)
2
Interior finishes (delta from quality baseline)
Add-ons (not in base rate)
Key quantities — auto-estimated · green border = manually overridden
Roof, cladding, and glazing costs are now calculated as area × delta rate. Deck, driveway, fencing, retaining, and lawn also use measured quantities. Override any value — it won't be reset when you change area or storeys.
Envelope (used in cost calc)
m²
m²
m²
Outdoor (used in cost calc)
m²
m²
lm
m²
Electrical, lighting & appliances
Electrical wiring and standard LED downlights are included in the base rate. Items below are upgrades/savings relative to that baseline. Appliances are listed separately and are not included in the base rate.
Electrical (delta from base)
Kitchen appliances — add-ons (not in base rate)
Laundry & hot water — add-ons
Home technology — add-ons
Landscaping & outdoor
m² × $35/m²
Consent, fees & professional services
Council consents & levies
Professional design fees
Site conditions
Easy / flat: standard site works, no difficulty premium on access-sensitive items.
Land purchase price
Optional. Enter the price you paid or expect to pay for the land. This is added to the build cost to give your total project investment. Land price does not attract GST when purchased privately in NZ.
$Leave 0 to exclude
Timing & escalation
Construction costs in NZ are tracked by the Stats NZ Capital Goods Price Index (CGPI) — residential buildings, not general CPI. Escalation is measured from the base cost date (when the rates in this model were current) to the midpoint of your construction — not from today. This means the model remains accurate even if opened years after the base rates were set.
Formula: Escalated cost = Base cost × (1 + rate)months from base cost date to construction midpoint ÷ 12
Base cost date → Construction start → Construction midpoint (start + ½ duration)
Dates
Rawlinsons 2024–25 ≈ Jul 2025
Escalation rate
% per year
Contract type
Escalation exposure
Medium exposure: fixed price with some PC sums / exclusions. Owner carries risk on provisional items and any scope changes.
Escalation results
Months to midpoint
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Escalation factor
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Escalation amount
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Escalated build cost
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Owner exposure
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Construction loan (optional)
A construction loan funds your build via progressive drawdowns. Interest accrues only on funds drawn. Admin fee (2%) and agent fee (1.5%) are charged on the full loan amount. When escalation is active, the loan is calculated on the escalated build cost — i.e. the amount you will actually need to borrow at time of construction.
7.50%
2.0% of full loan amount
1.5% of full loan amount
Loan amount
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Admin fee (2%)
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Agent fee (1.5%)
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Est. interest
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Total loan costs
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Interest = avg drawn balance × rate × (months/12). Confirm all fees with your bank or mortgage broker.
① Today's estimate (current dollars, no escalation)
Low estimate
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Expected (today's $)
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High estimate
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② Escalated / out-turn estimate (future dollars)
Escalated low
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Out-turn total
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Escalated high
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Escalated build cost → + finance costs → + land → = out-turn total. Escalation applies to construction costs only.
Full cost breakdown
Base rates (2024–25, Auckland basis, adjusted for realistic contractor pricing) include concrete slab, corrugated steel roof, standard aluminium DG windows, kitchen joinery (no appliances), 2× standard bathrooms, standard electrical + LED downlights, carpet/vinyl flooring, and multi-room heat pumps. Specification items are deltas from quality baselines — not full costs — to avoid double-counting. Cladding, roof, and glazing use quantity × delta rate per m².
Four-output model: ① Today's build cost (hard/soft construction costs, current dollars) → ② Escalated build cost (construction costs × CGPI escalation factor to midpoint of build) → ③ Finance cost (loan costs calculated on the escalated build cost, not today's cost) → ④ Final out-turn total (escalated build + finance + land). Escalation applies to construction costs only, not loan costs or land.
Stats NZ CGPI (Capital Goods Price Index — residential buildings) is used for escalation, not general CPI. CPI understates construction cost movements. Contingency is dynamic (8–30%) based on build type and site risk. Site difficulty multiplier applies to foundation, retaining, drainage, driveway, and deck. MBIE levy calculated at post-1 July 2024 rate. Always obtain at least 3 quotes from licensed building practitioners (LBPs). Does not include land purchase.