“Quantity surveyor” and “estimator” are often used as if they mean the same thing, and on many builders’ teams one person does both jobs. They are different roles, though, with different goals. Knowing the difference helps you hire the right person, or engage the right consultant, for your project.
This article combines our two earlier comparisons of estimation and quantity surveying into one guide.
What does an estimator do?
A construction estimator works out what a project, or a package of work, will cost to build. The main output is a price, usually a tender or quotation. The estimator:
- reviews drawings and specifications and identifies the scope;
- measures quantities (the take-off);
- prices labour, materials, plant and subcontract quotes;
- adds preliminaries, risk, overheads and margin;
- writes up qualifications and exclusions and submits the bid.
See the role of a cost estimator in construction.
What does a quantity surveyor do?
A quantity surveyor manages cost across the whole life of a project: feasibility, cost planning, bills of quantities, tendering, progress claims, variations and the final account. A QS may work for the client (consultant QS) or for the builder (contractor’s QS). Read the full list of QS duties and responsibilities.
Key differences at a glance
| Estimator | Quantity surveyor | |
|---|---|---|
| Main goal | Produce an accurate, competitive price | Control cost and value across the project |
| Project stage | Mainly pre-contract (tender) | Feasibility through to final account |
| Typical employer | Builders, subcontractors, suppliers | Clients, consultants, builders |
| Key outputs | Take-offs, priced estimates, tender submissions | Cost plans, BoQs, cost reports, claim assessments, final accounts |
| Contract involvement | Limited after award | Central: variations, progress claims, EOT costs |
| Focus | “What will it cost us to build?” | “What should it cost, and is it on track?” |
Where the roles overlap
Both roles measure quantities and understand construction costs. On a mid-size Perth building company, the “estimator” often prices the job and then, as contract QS, runs claims and variations once it is won. Consultant QSs also prepare pre-tender estimates using the same estimating skills.
How they work together on a project
- The client’s QS prepares the cost plan and a bill of quantities for tender.
- Builders’ estimators price the BoQ or their own take-off and submit tenders.
- The client’s QS compares tenders against the pre-tender estimate and recommends one.
- During construction, the builder’s QS lodges claims and the client’s QS assesses them.
Which do you need?
- You are a builder or subcontractor bidding for work: you need estimating. Outsourced construction estimating or a material take-off can add capacity during busy tender periods.
- You are an owner, developer or investor: you need a QS to set and protect the budget, and to check what you are being charged.
- You are a builder running a live project: you need contract QS support for claims, variations and the final account.
Frequently asked questions
Is a quantity surveyor more qualified than an estimator?
Not necessarily. Many QSs hold a degree and AIQS or RICS membership. Many experienced estimators come up through a trade or construction management. What matters is relevant experience on your type of project.
Can one consultant do both?
Yes. Measure Manage provides both estimating and quantity surveying services in Perth and across WA, and is RICS & AIQS Accredited.
Which is cheaper?
An estimate for a single tender is usually a fixed, one-off fee. QS services may run for the whole project. The right choice depends on the risk you are trying to manage, not the fee alone.
Not sure which service you need? Call Measure Manage on 0498 202 445 and we’ll tell you straight. See our quantity surveying and estimating services.