7 Red Flags to Check Before Signing an HIA Building Contract in NSW

How to use this guide

Work through the seven red flags with your contract open beside you. For each one, we explain what the clause is meant to do, how it is commonly used against owners, and the specific things to check before you sign. At the end you'll find a one-page pre-signing checklist that pulls it all together.

A note before you start: the standard HIA contract itself is not the enemy. It is a widely used, reasonably balanced document. The risk lives in how it is filled in — the allowances, the schedules, the attached special conditions — and that is exactly where most owners stop reading.

1. Prime cost items and provisional sums

Prime cost (PC) items are allowances for products not yet selected — tapware, tiles, appliances, door hardware. Provisional sums are allowances for work not yet fully priced — site works, excavation, rock removal, retaining walls. Both are estimates, and the contract lets the builder adjust the price when the real cost is known.

Here's the trap: a builder who wants their tender to look cheap can set these allowances unrealistically low. The contract price looks attractive on signing day, then every allowance blows out during the build — and the adjustment lands on you, usually with the builder's margin added on top of the overrun.

A worked example: a provisional sum of

2. Variation clauses

Variations are the single biggest source of disputes on residential builds in NSW. Every change from the contract documents — whether you asked for it or the site demanded it — flows through the variation clause, and the detail of that clause decides who pays and how much.

Read closely: who can initiate a variation, does it have to be in writing and signed by you before work proceeds, what margin does the builder add, and what happens if work is done without a signed variation? A contract that lets the builder proceed on a verbal instruction and invoice you later is a blank cheque.

Also watch the margin stacking. A variation priced at cost plus 25%, on top of allowances that were low to begin with, means the builder can profit more from changes than from the original contract. That is the wrong incentive to hand anyone.

• No variation should proceed without your written, signed approval — check the clause says so
• Confirm the builder's variation margin and compare it to their tender margin
• Check whether 'unforeseen site conditions' variations require evidence (photos, reports) before you must pay
• Keep every variation in writing during the build, even when the builder is friendly — especially when the builder is friendly

3. Delay damages and extension of time claims

Every contract has a building period and a mechanism for extending it — weather, supply delays, council holdups, variations. The questions that matter are: how easily can the builder claim an extension, do they have to notify you within a set time, and what do you receive if the build still runs late?

Look for the liquidated damages figure — the amount the builder owes you per week of unexcused delay. It is often filled in at a token amount, or left blank, which can mean you're paying rent or a bridging loan for months with no meaningful compensation flowing back.

Then flip it: check what delay costs the builder can claim from you if you cause a holdup (late selections, late payments). The two sides of the delay clause should feel roughly fair. They frequently don't.

• Confirm liquidated damages are a realistic figure — compare them to your actual weekly holding costs (rent, interest, storage)
• Check the builder must claim extensions of time in writing within a fixed number of days of the delay arising
• Count the calendar: does the building period already include a reasonable allowance for wet weather and holidays?
• Beware special conditions that quietly delete or cap liquidated damages entirely

4. Cost escalation clauses

Rise-and-fall or cost escalation clauses let the builder pass on increases in material and labour costs after signing. They became common when material prices spiked, and many builders have kept them in place since.

On a 12-month build, an open-ended escalation clause can move the price by tens of thousands of dollars — and unlike a variation, you never approved anything. Some clauses are indexed and capped; others simply say the builder may pass on 'increased costs', which is close to no fixed price at all.

A fixed-price contract with a broad escalation clause is not a fixed-price contract. Make sure you know which one you're actually signing.

• Check whether any rise-and-fall or cost escalation clause exists — often it hides in the special conditions, not the standard terms
• If one exists: is it capped, is it indexed to something objective, and does the builder have to prove the cost increase?
• Ask the builder to delete or cap the clause before signing — this is a normal negotiation, not an insult

5. Progress payment schedule

NSW law caps deposits on most home building contracts (currently 10% for typical contracts — check the current rules for yours), and progress payments are meant to reflect work actually completed. But 'meant to' is doing a lot of work in that sentence — front-loaded schedules still appear constantly.

A front-loaded schedule means you've paid, say, 60% of the contract price when only 40% of the value is in the ground. If the builder then slows down, becomes insolvent or walks away, you are out of pocket for work that doesn't exist, and the insurance process is slow and capped.

The stage definitions matter as much as the percentages. 'Frame stage' should mean the frame is complete and inspected — not that frame materials have been delivered to site.

• Add up the schedule: at each stage, does money paid roughly match value built?
• Check each stage is defined by completed, inspectable work — not deliveries or 'commencement' of a stage
• Confirm the deposit is within the current legal cap for your contract type and value
• Never pay ahead of the schedule, no matter how reasonable the request sounds mid-build

6. Missing or vague inclusions

The contract documents — plans, specifications, inclusions schedule — should describe precisely what you are buying: brands, models, colours, quantities and standards of finish. Every vague line is a decision that will be made later, by the builder, at your cost.

Phrases to hunt for: 'standard range', 'builder's selection', 'or equivalent', 'as required', 'allowance only'. Each one is a door left open. 'Or equivalent' in particular lets a builder substitute a cheaper product and argue equivalence after it's installed.

Cross-check the inclusions schedule against the display home or the sales conversation. What you were shown and what is written down are often two different specifications — and in a dispute, the written contract documents are what everyone falls back on.

• Every appliance, fixture and finish should have a brand and model number or a realistic PC allowance
• Strike or clarify 'or equivalent' wording on items you care about
• Confirm quantities, not just products — how many downlights, how many metres of benchtop
• If it was promised verbally, get it added to the contract documents before signing — afterwards is too late

7. Special conditions that override your protections

Special conditions are extra clauses attached to the standard HIA terms — and they are typically drafted to take priority over the printed contract. Builders' lawyers write them, and they almost never move risk in your direction.

Common examples we see: liquidated damages deleted or capped at

Your pre-signing checklist

Ten minutes with this list before you sign can save months of dispute later. If you can't tick an item, that's not necessarily a reason to walk away — it's a reason to ask questions and negotiate before your signature makes the terms permanent.

• Every PC item and provisional sum checked against real market prices
• Variations require your signed written approval before work proceeds
• Liquidated damages set at a realistic weekly figure — not blank, not
• No open-ended cost escalation clause (or capped and indexed if unavoidable)
• Progress payments track completed work; deposit within the legal cap
• Every inclusion specified by brand, model and quantity — no 'builder's selection' on items that matter
• Every special condition read, understood and explained to your satisfaction
• Plans, specifications and inclusions schedule all attached, consistent and signed
• Builder's licence and insurance verified before exchange (see our builder vetting guide)

Frequently Asked Questions

Should I get a HIA contract reviewed before signing in NSW?

Yes. HIA contracts routinely run past 60 pages, and the clauses most likely to cost you money — variations, prime cost items, provisional sums, delay provisions and special conditions — are rarely obvious. An independent review before signing typically costs a few hundred dollars and routinely identifies risks worth tens of thousands. Helios Project Management offers a fixed-fee HIA contract review at $500 inc. GST with a written report within 24 hours of receiving your documents.

What are prime cost items and provisional sums in a HIA contract?

Prime cost (PC) items and provisional sums are allowances for parts of the build not fully priced when the contract is signed — tapware, tiles, site works and similar. If the allowances are set unrealistically low, the contract price looks attractive but the real cost lands on you later as an adjustment. Every allowance should be checked against realistic market pricing before you sign.

What is the biggest red flag in a building contract?

Special conditions that override the standard HIA protections are the most dangerous part of most contracts, because builders rarely amend the standard terms in the owner's favour. Close behind are vague variation clauses, cost escalation clauses, and front-loaded payment schedules that put your money ahead of the work.

Can a builder charge me for variations I never approved in writing?

Most residential building contracts require variations to be documented in writing, priced and approved before the work is done. Whether a builder can recover payment for unapproved variations depends on the contract wording and the circumstances — which is exactly why the variation clause deserves scrutiny before you sign, not after the first dispute.

How much does a HIA contract review cost in NSW?

Helios Project Management reviews HIA, MBA, ABIC and custom building contracts for a fixed fee of $500 inc. GST, NSW-wide. The review is clause-by-clause and includes a personalised written risk report within 24 hours of receiving your documents, plus email support if anything in the findings is unclear. An optional 30-minute video walkthrough of the findings can be added at booking.