What a quantity surveyor does on a project in Oman, and when to hire one

The first job is an order-of-cost estimate, then an elemental cost plan as the design develops: substructure, frame, envelope, finishes, services and external works, each with a budget. This is where the quantity surveyor earns the fee. Changing the structural grid on paper costs nothing. Changing it after tender costs a variation.

The quantity surveyor measures the drawings into a bill of quantities using a standard method of measurement, usually NRM or SMM in Oman, so every item is traceable to a drawing and every contractor prices the same quantities. The bill goes out with the specification, the preliminaries and the contract conditions. When bids return, the QS checks arithmetic and rates, normalises exclusions and recommends the award.

Each month the QS measures the work in place, checks the contractor's payment application against it and certifies the amount earned. Variations are measured and valued when they are instructed, not argued about at the end. A monthly cost report states the cost to date, the cost to complete and the forecast final account, so the client is never surprised.

The final account reconciles the contract sum, the measured work, the variations, any claims and the retention into one agreed figure. Done properly, it is a formality. Done badly, it is a dispute.

Contractors employ quantity surveyors to price work and protect their margin. A client-side QS does the opposite: independent measurement, independent certification and advice that is only ever for the owner. On any project of size you want your own.

NRM, the RICS New Rules of Measurement, and the older Standard Method of Measurement are the measurement standards most bills follow. FIDIC forms are the most common standard contracts on larger private and public projects, with the Oman Standard Documents used on government work. Your QS should be fluent in whichever your contract uses.