AS 4000 のもとで variation を積算する

Raise the variation the day the change appears, with the date, who asked, what changed and whether a written direction from the Superintendent exists yet. Where it does not, ask for one and record that you asked, in writing, before the work starts.

理由: Clause 36 makes the Superintendent's direction the thing that turns extra work into a variation, and an architect or a client representative walking the site is usually neither the Superintendent nor authorised to direct one. Work built on a conversation is work you are asking to be paid for as a favour, and the answer arrives after it is already in the building.

Collect the daily labour, plant and material records for the varied work as it happens, have them signed on site by the Superintendent's representative where the contract asks for that, and attach the photographs and the delivery dockets to the same entry.

理由: Every valuation route in clause 36 except an agreed price ends up resting on what the work actually took. Records signed at the time settle that in a sentence; records assembled afterwards start a second argument about whether the record is true, and that one is lost even when the claim is good.

Work down clause 36 in order rather than jumping to the answer you want. A price the parties have already agreed governs; failing that, the rates and prices in the contract, applied to the varied quantity; failing that, rates in the contract used as a basis where the work is comparable; and only where none of those reach it, reasonable rates and prices. Record which route the valuation used and why the ones above it did not apply.

理由: Naming the route is what makes the number reviewable. A valuation that simply arrives at a figure invites the Superintendent to arrive at a different one, and there is then nothing in dispute except two opinions. A valuation that says which limb of the clause it used and why the earlier limbs did not fit can be disagreed with on a point, and points get resolved.

Serve the claim in the form and inside the period the contract requires, and record the date it went. AS 4000 puts a notification requirement around claims other than progress claims in clause 41, and the Annexure may shorten the period further, so read the Annexure rather than assuming the printed default.

理由: A time bar does not care whether the claim was good. It is the one defence a principal can run without engaging with the merits at all, and it succeeds on a date rather than on an argument. The claim that is worth the most is usually the one that took the longest to price, which is exactly the one that misses the window.

Include the valued variation in the next progress claim as its own line, showing what you claim and what has been certified, so an amount in dispute is a visible difference on one line rather than a shortfall on the total.

理由: A variation held back until it is agreed is a variation that is never claimed and never certified, and the money sits with the contractor for the length of the job. Claiming it keeps it on the record, keeps it inside the payment machinery the contract and the state statute provide, and makes the disagreement about one line instead of the month.

Post the agreed or determined amount against the contract so the contract sum moves as each variation closes, and keep the list of open variations with what each one is claimed at beside it.

理由: A final account is either a running total that both parties have been reading all along or an event, and the event version takes months. Every variation closed as it happened is one fewer item in a negotiation held at the point where the contractor most needs the money and has the least leverage.