A construction estimator works out what it should cost to build something. That sounds simple until you try it on a real project, where the drawings are incomplete, three trades overlap, and the client has already decided what they want to spend.
The core of the job: measurement
Everything starts with quantities. The estimator reads the drawings and measures the work: cubic metres of concrete, square metres of brickwork and plaster, linear metres of drainage, numbers of doors, windows and sanitary fittings.
This is the part most builders underestimate in terms of time. Measuring a modest two-storey extension properly — not approximating it — takes hours of focused work, and it is where accuracy is either won or lost. An area measured 10% short stays 10% short all the way through to the final price.
Pricing the quantities
Once quantities exist, they need rates. Each measured item gets a cost built from materials, labour, plant and any wastage or allowance appropriate to the work.
- Materials — current supplier pricing rather than last year's figures
- Labour — realistic outputs for the work and the conditions on this site
- Plant and access — scaffolding, excavators, hoists, welfare
- Preliminaries — site setup, skips, supervision, temporary works
- Allowances — waste, contingency on unknowns, provisional items
Asking the questions nobody else has asked
A good estimator spends a surprising amount of time on things that are missing. Does the drawing show the existing floor level? Is the steel designed? Who is paying for the party wall award? Is the drainage connecting to a public sewer or a private one?
Every unanswered question is commercial risk. It either gets clarified, priced with a stated assumption, or excluded in writing. The one thing it must not do is disappear silently into a lump sum.
Estimate versus quotation
These get used interchangeably and they are not the same thing. An estimate is a calculation of likely cost. A quotation is a commercial offer to carry the work out for a stated figure, with terms attached.
The estimate belongs to you and shows what the job should cost. What you then put in front of the client — your margin, your terms, your inclusions and exclusions — is a business decision, and it is yours to make.
Why builders outsource it
Estimating is not difficult because the maths is hard. It is difficult because it needs several hours of uninterrupted concentration, and site-based builders do not have those hours between 7am and 6pm.
The result is pricing done late at night, at speed, under tiredness — on the documents that determine whether the job makes money. Outsourcing moves that work into normal hours and puts a second experienced pair of eyes on the numbers before they reach the client.
What to look for
- Work measured from the drawings, not derived from a rate per square metre
- Assumptions, inclusions and exclusions stated in writing
- A breakdown you can interrogate rather than a single total
- Someone who asks you questions before finishing the estimate
- A fee agreed in advance, not after the work
If you want to see how that works on a live project, send the drawings across and we'll confirm the scope, the fee and the turnaround before anything starts.