How to Track Construction Costs (Budget, Committed, Invoiced, Paid)

Most builders find out a job has gone over budget when the last invoices arrive, two months after the decision that caused it. By then the money is spent, the client has moved in, and the conversation is about who pays, not how to stop it. Cost tracking that works tells you about the over-run on the day the quote is accepted, which is the last day anything can still be done about it.

One number per cost is not enough

A budget spreadsheet with one column, the quoted amount, tells you what you hoped. It cannot tell you where you are. For every cost on the job you need four numbers.

Budget: what the quote allowed for this item, adjusted for approved variations.

Committed: what you have agreed to spend. A subcontractor’s quote you accepted, a materials order you placed. The money is as good as gone, even though no invoice exists yet.

Invoiced: what has actually been billed to you.

Paid: what has left the bank.

The forecast final cost for each item is the largest of the revised budget, the committed amount and the invoiced amount. That single rule is what makes the sheet useful. The day you accept a plumber’s quote that is $3,000 over the allowance, the forecast moves, and you can see it.

Give every cost a code

Site, foundations, framing, roofing, cladding, joinery, electrical, plumbing, linings, painting, flooring, kitchen, landscaping, consent and fees, preliminaries. Twenty to thirty codes is enough for a residential job. Every quote, order and invoice gets coded the day it arrives, and the sheet totals by code. A cost that does not have a code goes to a holding line, and the holding line is reviewed weekly until it is empty.

Variations go in the day they are raised

A variation that is agreed on site on Tuesday and written up at the end of the month is a budget leak. Log it the day it is raised, with a description and the code it belongs to. Give it an amount only when it is priced and approved by the client, with the date. The budget sheet then adds the approved amount to the right code and the forecast final moves with it.

Unapproved variations sit in their own list with a pending amount. That list, reviewed weekly, is where most over-runs are visible before they happen: six “small” pending variations that add up to $14,000.

Send the client the sheet

With every progress claim, send a one-page summary: budget by code, forecast final by code, variations approved and pending. Clients who see the sheet every month do not get a surprise at the end, and they approve variations faster because they can see the total moving. Across 13,567 publicly posted reviews of NZ builders and outdoor and civil contractors, value is the lowest-scoring of the four rated dimensions at 97.6 out of 100 for both groups, and quote accuracy is praised in only 13.9% of positive builder reviews and 12.9% for civil work. The work is rated higher than the price, and the gap closes when the client has watched the number the whole way through rather than met it at the end.

Review it weekly, on the same day

Fifteen minutes, every Friday. Code anything in the holding line. Update committed amounts for quotes accepted this week. Enter invoices received. Look at the three codes with the biggest gap between budget and forecast, and decide what to do about each. Chase any variation that has been pending more than a week.

That routine, kept for the length of the job, is the difference between a builder who knows the final cost in week six and one who finds out in week twenty.

A tracker

The construction cost tracker in our resource library is a free Excel workbook with the cost codes, the four columns per code, the forecast-final rule built in, a variations log that feeds the budget, and a one-page client summary, with a renovation budget worksheet in PDF for the client side. Download it, put the quote in, and start coding from the first order.

Projects rarely go over budget in one jump. They go over one unlogged variation at a time.