How to Price a Construction Tender in NZ Without the Hidden 25%

Steve Parker
4 days ago
9 min read

How to price a construction tender in NZ from first principles, surface the hidden ~25% risk loading most subbies bury in their rates, and win on a defensible price.

By Steve Parker · Trueworks · NZ construction estimation · 8 min

Most Auckland subbie tenders carry a hidden risk loading of around 25 percent, smuggled across the rates "because the job will be a stuff-up" — and once it is buried, you can neither defend it nor protect it.

What you'll learn

How padding hidden inside material, labour and overhead rates can push a tender toward double the true cost
How to build a price from first principles: labour, materials, plant, P&G, scope-gap allowance, explicit risk, margin
How an itemised contingency line wins more work and protects margin better than buried padding

Quick answer: To price a construction tender in NZ properly, build the cost from first principles — labour, materials, plant, preliminaries and general (P&G) — then add three visible lines on top: a scope-gap allowance for incomplete design, an explicit risk and contingency line, and your margin. Most subcontractors instead bury a roughly 25 percent risk loading inside their rates, which inflates the bid (often toward double the true base cost), can be read as a payment-trust signal, and is impossible to defend if the head contractor questions it. An itemised contingency is easier to justify, easier to win on, and easier to protect when the job goes sideways.

Why a buried 25 percent quietly doubles your price

Walk through how a typical bid gets built and you find padding in three places at once. The labour rate gets nudged up "in case the gang is slow on this one". The material rate carries a fat allowance "because there'll be waste and re-orders". The overhead percentage gets a quiet bump "to cover the hassle". None of it is written down as risk. It is all dressed up as cost.

The trouble is that these loadings compound. A 10 percent pad on labour, a 10 percent pad on materials and a stretched overhead rate do not add to 30 percent — they stack on top of one another, and then your margin is calculated on the already-inflated number. We routinely see tenders where the genuine first-principles cost of the work is somewhere around half the tendered figure once you strip the hidden loadings out. The subbie is not gouging; they genuinely believe the job will be a mess, and they have learned to price for the worst week they have ever had. But because the loading is invisible, nobody — not the estimator, not the head contractor, not the subbie themselves six months later — can say what it is actually for.

There is a second, quieter driver: trust. We see the same firm price the identical scope differently for two head contractors. For the one with a clean payment record they price tight. For the one who has dragged out a payment claim before, the number climbs. That gap is not scope. It is the subbie encoding payment risk into the rates — pricing the relationship, not the work. The Construction Contracts Act 2002 payment-claim and payment-schedule regime exists precisely to take some of that risk off the table, but a burnt subbie prices defensively anyway.

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Where the padding actually hides

The padding never announces itself. It lives inside the unit rates, which is exactly why it is so hard to argue with — and so hard to defend. Knowing the usual hiding spots is the first step to pulling them out into the open.

Labour rates carry the biggest single pad, because labour is where a bad job actually hurts. "Allow a bit extra on the hours" is the most common instruction an estimator gets.
Material rates absorb waste, re-order and price-movement risk that should sit in a separate allowance, so the same risk often gets counted twice.
Overhead and margin get stretched together until nobody can tell where cost recovery ends and profit begins.
Provisional and prime-cost (PC) items get padded as if they were fixed, even though they are estimates by definition — a fixed-price contract only fixes the price for the defined scope, not for PC sums.

The Trueworks Per-Project pack is NZ$8,000–12,000 for the full estimation, risk register, contingencies table and pre-trade-start sheets across all major trades on a build. Builders typically save NZ$10,000–20,000 of their own time per job. See pricing on trueworks.co.nz →

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First-principles build-up: the seven honest lines

The fix is not to price lower. It is to price the same total in a way you can stand behind. Build the number from the ground up and keep every layer visible.

Labour — real productivity rates for real conditions: crew size, output per hour, the all-up cost of an hour on the tools in Auckland (wages, on-costs, supervision). No "buffer" hours hidden here.
Materials — measured quantities at current supplier pricing, plus a stated, sensible waste factor (and say what it is — five percent reads very differently from twenty).
Plant and equipment — hire, fuel, transport and standing time, priced to the programme rather than guessed.
Preliminaries and general (P&G) — site setup, access, scaffolding, temporary services, your share of the main contractor's site overheads, and the cost of simply being on a site for the planned duration.
Scope-gap allowance — a named line for the design that is not finished. NZ fixed-price jobs are routinely let on incomplete design, often only 60 to 70 percent complete; the missing detail resurfaces as variations and disputes. Price what you can see, and put a visible number against what you cannot.
Risk and contingency — the line that replaces all the buried padding. State the percentage, state what it covers (ground uncertainty, weather, sequencing, the few items you genuinely cannot pin down), and qualify your assumptions in the tender so the allowance is anchored to something real.
Margin — your overhead recovery and profit, applied once, on a clean base. Calculated last, on honest numbers, so you actually know what you are making.

Ground conditions deserve their own note, because they are the single most common origin of delay and variation claims in NZ. Competent contractors qualify — "tag out" — ground risk at tender rather than swallowing it silently into the rates. Pile depth and count overruns surface after piling starts and are among the most expensive moments on any job to discover. Name that risk in line 5 and line 6; do not bury it in line 1.

Hidden padding vs the explicit-line approach

Labour — hidden-padding approach: the rate is quietly inflated 10–15% "for slow days". Explicit-line approach: a true productivity rate, with the slack moved to the risk line.
Materials — hidden: waste and re-order risk baked into the rate. Explicit: measured quantity plus a stated waste percentage, with price risk in contingency.
Plant — hidden: padded standing time inside the rate. Explicit: priced to programme, with idle-time risk shown separately.
Preliminaries and general — hidden: buffered duration absorbed into prelims. Explicit: real site costs for the planned programme.
Scope gap — hidden: invisible, guessed at and smeared across the rates. Explicit: a named allowance against incomplete (60–70%) design.
Risk and contingency — hidden: does not exist as a line, so it lives everywhere. Explicit: one stated percentage, with what it covers written down.
Margin — hidden: calculated on an already-inflated base. Explicit: applied once, on a clean first-principles cost.
Total effect — hidden: drifts toward roughly twice true cost and is impossible to defend. Explicit: the same or a lower total, with every dollar defensible.

The two columns can land on a similar total. The difference is that the right-hand column can be defended line by line — and that is what wins the job and protects the margin when the head contractor starts negotiating.

How to price your next tender from first principles

Measure the scope first, price it second. Take off quantities from the drawings before you touch a single rate. If a quantity is a guess, flag it as a guess.
Strip every buried buffer out of your rates. Get back to genuine productivity and supplier numbers. You are not lowering the price — you are relocating the risk to where it can be seen.
Add a named scope-gap allowance. Decide how complete the design really is. If it is 60 to 70 percent, your price for the rest is an estimate, and you should say so.
Add one explicit risk and contingency line. Put a percentage on it, write down what it covers, and keep it separate from margin. A visible 8–12 percent contingency is far easier to defend than the same allowance smeared invisibly across the rates.
Qualify your assumptions in the tender. Tag out ground risk, state your programme assumptions, list provisional and PC sums as estimates, and reference the contract's variation valuation rules so everyone knows how extras will be priced if the scope moves. Building a pre-tender risk register before you submit forces every one of these out into the open.
Apply margin last, on the clean base. Now you know your true cost, your stated risk position and your real profit — three separate, defensible numbers instead of one opaque one.

Under most NZ construct contracts the rules for pricing extras are set in advance — for example, the variations provisions of NZS 3910 follow a valuation hierarchy (an agreed price first, then contract rates, then reasonable rates, then daywork). Pricing your base bid from first principles means you can plug straight into that hierarchy when a variation lands, instead of arguing from a rate nobody can explain. Watch margin stacking too: a main contractor typically adds 10 to 15 percent on a variation, your own price already carries its margin, and stacked up the chain the client commonly pays 20 to 30 percent on top of the base cost — so a clean, transparent base price benefits everyone, including you.

This is general information, not legal advice — get advice on your specific contract.

FAQ — pricing a construction tender in NZ

Q1: How much risk allowance should I put in a construction tender in NZ? There is no single correct figure — it depends on how complete the design is and how well you understand the ground. The point is to make it explicit. A stated 8 to 12 percent contingency, with a note on what it covers, is far easier to defend than the same allowance hidden inside your rates. On jobs with significant ground or design uncertainty it may be higher, and you should say why.

Q2: What does pricing a tender "from first principles" actually mean? It means building the cost up from measured quantities and genuine productivity, plant and supplier rates — rather than applying a gut-feel square-metre rate. You add P&G, a scope-gap allowance, an explicit risk line and margin as separate, visible layers. The result is a number you can take apart and defend line by line.

Q3: Why do two head contractors get different prices from me for the same scope? Usually because you are pricing payment risk, not just the work. A contractor you trust on payment gets a tighter number; one who has dragged out a payment claim gets a higher one. That trust premium is real, but burying it in your rates hides it from you too — far better to manage payment risk directly, using the Construction Contracts Act 2002 payment-schedule regime, than to smuggle it into the bid.

Q4: Is a "fixed-price" tender really fixed? Only for the defined scope. Provisional sums and prime-cost (PC) items are estimates, not fixed prices, and any work outside the drawn-and-specified scope is a variation. NZ jobs are commonly let on 60 to 70 percent complete design, so the missing detail tends to return as variations and provisional-sum overruns. Price what is defined, and flag the rest as allowances.

Q5: How do I defend my contingency if a head contractor pushes back on it? By having itemised it in the first place. If your contingency is a named line with a stated coverage — ground uncertainty, weather, sequencing — you can point to exactly what it is for and negotiate it on the merits. If it is buried in your rates, you have nothing to point at, so the only lever in a negotiation is to drop your price blind and surrender margin.

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About Trueworks

Trueworks is built by Steve Parker — 20 years on the analytical side of NZ construction. Variation reviews, contract advisory, programme review, and AI-augmented document workflows. Trueworks is the productisation of that practice for builders: same defensible analysis, at a price and pace a NZ builder can actually use.

I answer every email personally during pilot phase. If you've got a quote you want a second opinion on, the easiest way to find out if Trueworks is useful is to send it.

hello@trueworks.co.nz · trueworks.co.nz/contact

Pricing a tender right now? Send the pack — take-off checked, rates benchmarked, risks flagged, in writing, within 24 hours. Send us the drawings and the quote, tender or variation. You get a written, code-cited check back within 24 hours. No charge for your first check. No card, no obligation. NDA available. → Get the free check at trueworks.co.nz/contact — or email hello@trueworks.co.nz