AEC definitions
A bill of quantities is a document that lists the measured items of work, prepared so every bidder prices the same quantities. Contractors enter unit rates. The total is the price. It is standard in many international and quantity-surveying contracts. In U.S. lump-sum practice each bidder often does their own takeoff instead.
Definition
A quantity surveyor or the design team's consultant measures from the drawings and writes the bill by a standard method of measurement. Bidders do not argue about the quantity on bid day. They argue about the rate. After award, variations remeasure the changed quantities. The bill is not a specification. Descriptions point at the spec. Errors in the quantities are corrected under the contract's rules, which may entitle the contractor to an adjustment. A U.S. unit-price bid form is a cousin, usually shorter and aimed at civil quantities.
In depth
The method of measurement defines what is included in a cubic meter or a linear meter. Bidders read that method before they price. A rate that assumes a different inclusion will be wrong.
Preliminaries, the general-requirements items, are often separate from the measured work.
The bill describes the result. The contractor's rate includes labor, plant, and method. A change in method after award does not change the rate by itself.
Unbalanced rates, high on early items and low on later ones, are a cash-flow tactic owners watch for.
If the bill under-measured and the contract says quantities are subject to remeasurement, the contractor is paid the corrected quantity.
If the contract says the contractor was to verify, the risk sits differently. Read the form. Do not assume FIDIC and a U.S. lump sum work the same way.
Interim payments measure percent complete on bill items.
That is similar in spirit to a schedule of values, with the item list fixed at tender. Variations add new bill items or change quantities.
Examples
Every bidder prices the same 1,200 cubic meters of concrete. The low bidder is low on rates, not on a smaller takeoff.
A variation increases excavation. The bill quantity is remeasured and paid at the tendered rate.
Preliminaries are a separate section. They are not hidden inside the concrete rate.
FAQ
Unlock the value of your institutional knowledge—organized, connected, and grounded in your team's critical workflows with Nomic.
