What is a BOQ?
As per the definition given by Cambridge dictionary, a Bill of Quantities is a document showing a list of everything needed to build something and how much each item will cost.
NRM 2 defines a BOQ as a list of items giving detailed identifying descriptions and firm
quantities of the work comprised in a contract.
Basically it is a list of items forming part of a construction project with information about their units, quantities, rates and amounts.
What does it contain?
Preliminaries contain all the indirect cost items required for the execution of the project which cannot be directly attributed to any particular activity. E.g. Site office, Staff salaries, Tower crane etc. They are generally given as a lumpsum amount.
Measured works are the actual work that will be carried out for completing the project. The amount for measured works is calculated by multiplying the quantities with their rates. In remeasurable type contracts, these items are remeasured again after completion of the work to arrive at the accurate final amount of work done.
Provisional Sums are given for items of work which have little or no design and information. They are given as a lumpsum amount and are adjusted after the execution of the project.
When and why is it used?
A BOQ is used during the entire lifecycle of a project.
During the designing stage, it can be used to estimate the cost of the project and control the design.
During the Tendering stage, it is used to form a basis for all the bidders to bid for the project. Bidders are given the BOQ by the client along with the RFQ and they quote their rates against each item which ultimately gives the final price they are quoting for the project. It forms the basis for preparing the Comparison Statement for comparing of different quotations received for the work.
Once the tendering stage is complete and the contract is finalized, the BOQ forms an integral part of the contract which is used to calculate the progressive payments of the contractors. It will be also used to
Who prepares it and how?
It is prepared by a QS or an Estimator by a process of Quantity Takeoff (QTO) which involves measurement of all the works based on the drawings and the specifications. Measurement is done using some standard measurement rules. (e.g. IS 1200, SMM7, POMI etc.) Various software are available today to assist in the Quantity Takeoff process (e.g. CostX, Autodesk Quantity Takeoff, On-Screen Takeoff etc.) With the advent of BIM, quantities can be generated easily from the information already available in the model.
The rates are arrived at by a process of Rate analysis which is basically breaking down each work into more detailed components such as Labour, Material, Plant & Machinery, overheads etc. The quantity of works multiplied by its rates gives the amount for the works.
How are the items arranged?
Items are usually arranged either as per the Trades (e.g. Shuttering, Concreting, Excavation etc.) or as per the Elements (e.g. Substructure, Superstructure, Finishes etc.).
There are various standard formats of arrangement of works in the BOQ, most notably the UniFormat (element based) and the MasterFormat (trade based).
The basic idea of arranging the items is to list them according to the flow of construction. For a Trades BOQ, Excavation will come first, then Shuttering, Reinforcement and Concreting and so on. Similarly for an Elemental BOQ, Substructure will come first, then Superstructure, Finishes etc.
Format of a BOQ