HIA building contracts: the form sets the clock
Most residential building work in New South Wales runs on a Housing Industry Association form. The entitlements it gives you — to a variation, to an extension of time, to a progress payment — are each conditional on something being done within a period the form itself fixes.
In short
- The HIA suite is a set of forms, not one contract, and the right one is chosen by the nature of the work and the way the price is arrived at.
- Before any money changes hands the Home Building Act 1989 (NSW) requires a compliant written contract and, above a prescribed value, home building compensation cover with a certificate given to the owner. The consequences of getting that wrong fall on the builder.
- A variation directed verbally and never confirmed in writing is one of the most common ways builders lose money on a residential job. Confirm the direction, the price and the time effect before the varied work starts.
- Extension of time entitlements usually depend on written notice inside a period the form sets. Special conditions often amend that period, and it is short.
- The defects liability period is not the limit of your exposure. It is the window in which you generally have both the obligation and the right to return and rectify.
Most residential building work in New South Wales runs on a standard form, and the Housing Industry Association suite is the one NSW residential builders hold most often. It is signed at the start of a job and read again only when something has gone wrong — the wrong order, because nearly every entitlement in it is conditional on doing something inside a period the form itself fixes. The Home Building Act 1989 (NSW) sets a floor of obligations behind the contract that cannot be contracted away. The contract sets the timetable, and it is the timetable that costs builders money.
Which form suits which job
The HIA publishes a suite rather than a single contract, and the right form is chosen by the nature of the work and the way the price is arrived at. Broadly, the categories used in New South Wales:
| Form category | Suits | Where the risk sits |
|---|---|---|
| New dwellings | A new home on a residential site, at a fixed price. | The builder wears cost movement unless a clause says otherwise. |
| Alterations and additions | Renovation, extension and second-storey work on an existing dwelling. | Latent conditions and access — what you cannot price before you open the wall. |
| Cost plus | Work priced as the cost of carrying it out plus an agreed margin. | The owner carries cost risk, so records and substantiation become the job. |
| Small or minor works | Lower-value jobs where the full machinery is disproportionate. | A shorter form means thinner procedural rights, in both directions. |
Run a genuinely cost plus job on a fixed-price form and every cost movement becomes a variation argument. Run a substantial renovation on a small works form and you will want the delay and variation machinery by week six.
The periods live in the schedules, not only in the clauses. HIA forms carry their operative time periods in the particulars and schedules, and those entries are often amended by special conditions negotiated after the form was chosen. Read the contract you actually signed, including the pages people skip.
Before you take the deposit
Three of the Act's requirements decide whether you can be paid at all, and all three are dealt with before anyone is on site. A contract for residential building work must meet the form requirements the Home Building Act 1989 (NSW) imposes — in writing, dated, signed, carrying the prescribed particulars and notices. Above the prescribed value, insurance under the home building compensation scheme must be in force and a certificate given to the owner before the builder demands or receives any payment. And the Act caps the deposit itself, and regulates payment in advance of work carried out.
Variations, and why a verbal direction is where the money goes
Variation claims are often lost on process rather than on merit. HIA forms generally require a variation to be in writing and signed before the varied work is carried out, and the Home Building Act 1989 (NSW) reinforces the point through its own requirements about the form of a residential building contract and how it may be varied.
What happens on site is different. The owner asks for the tiling to be changed while standing in the room. You do it, because it is a small thing and the relationship is good. Twelve of those accumulate over a job, and when the final claim goes in the owner disputes every one. The work is real. The evidence is a memory.
- Confirm the direction in writing before the varied work starts — what was asked, what it costs, and what it does to the completion date. If the owner will not sign, do not carry out the work.
- Price the time as well as the money. A variation approved without a time consequence is one you have agreed to absorb into the programme.
- Where the paperwork did not keep pace, the questions become whether the work was directed at all, whether the owner's own conduct answers the writing requirement, and how the contract says a variation is to be valued. Those arguments exist. They are harder than an email would have been.
Extensions of time
The extension of time machinery follows a familiar shape: a qualifying delay event, written notice to the owner inside the period the form sets, particulars of the cause and the delay claimed, and the owner's opportunity to dispute it. Give the notice and the date for completion moves, which is what protects you from liquidated damages. Miss it and the entitlement can be gone even where the delay was the owner's doing.
We do not quote a day count here, because editions differ and special conditions amend them. The form sets the period, and it is short. What matters is that the notice is the claim, not a courtesy that precedes it.
Progress payments and the claim procedure
HIA forms are usually staged: a deposit, then progress payments tied to defined stages — base, frame, lock-up, fixing, completion — or to a schedule of amounts. The claim procedure is where cash flow is won or lost.
- The claim must be for a stage actually reached as the contract defines it, not as the site foreman describes it. A great many stage disputes are really definition disputes.
- Serve it in the manner the contract requires, on the person the contract nominates, and keep proof of the date.
- The form gives the owner a period to pay or to dispute. What follows — interest, a right to suspend, a right to give a further notice — is conditional on that period having run.
- The Building and Construction Industry Security of Payment Act 1999 (NSW) does not apply to a construction contract for residential building work on any part of premises the party for whom the work is carried out resides in, or proposes to reside in — so on an owner–occupier job the contract is your recovery route, not adjudication.
The defects liability period
The defects liability period usually runs from practical completion and is routinely misread as the outer limit of the builder's exposure. It is not. It is the window in which the builder generally has both the obligation and the right to return and rectify — and the right matters, because an owner who engages someone else instead may have difficulty recovering that cost. Behind it sit the statutory warranties implied by the Home Building Act 1989 (NSW), which run for their own periods, distinguish major defects from other defects, and cannot be excluded or restricted by the contract.
The pattern worth taking away
Across variations, extensions of time, progress claims and defects, the same structure repeats: the contract creates the entitlement and the contract's own notice period extinguishes it — a period typically much shorter than any statutory limitation period. If a direction has been given or a delay event has happened, the first question is not what the law allows. It is what your form required you to send, to whom, and by when. We act for builders, contractors and developers in building contract disputes.
This article is general in nature and is not legal advice, and reading it does not create a solicitor–client relationship. It states the position as at the date above; the law changes, and this may since have been overtaken. Get advice on your own matter before acting on it.
Questions builders ask us about HIA forms.
The owner asked for a change verbally and now disputes it. Is the variation lost?
Not necessarily, but you are starting from behind. Where the contract required the variation to be in writing before the work was carried out, the questions become whether the work was in fact directed, whether the owner's own conduct answers the writing requirement, and how the contract says a variation is to be valued. Those arguments are available and are sometimes won. They cost a great deal more than the email would have.
Which HIA form should we be using for a large renovation?
Broadly, an alterations and additions form is built for work on an existing dwelling, where latent conditions and access carry the risk, while a new dwellings form assumes a clear site and a fixed price. A small works form suits jobs where the full delay and variation machinery would be disproportionate. Match the form to the work and to the pricing method before signing, because the form decides how any later argument runs.
Does security of payment apply to our residential jobs?
Usually not where the owner lives in, or proposes to live in, the premises. The Building and Construction Industry Security of Payment Act 1999 (NSW) does not apply to a construction contract for residential building work on that footing, so an owner–occupier job is a contract claim governed by the contract and the Home Building Act 1989 (NSW). Your subcontracts on a commercial job are a different question and may well be covered.
Does the defects liability period end our liability?
No. It is the period in which you generally have both the obligation and the right to come back and rectify, and it is worth insisting on that right, because an owner who brings in someone else may struggle to recover the cost. Separately, the statutory warranties implied by the Home Building Act 1989 (NSW) run for their own periods and cannot be excluded or restricted by the contract.
Tell us what's happened.
Send us the executed contract, the special conditions and the date of the direction or the delay event, and we will tell you what the form required and whether the entitlement is still there.
Information on this site is general in nature and is not legal advice, and may have been overtaken by a change in the law. Contacting us does not create a solicitor–client relationship.