What is a Bill of Quantities or BOQ?
Updated: Jan 15
A “BOQ” is an acronym for the words “Bill of Quantities”
A BOQ is a detailed and itemised pricing document that banks, developers, consultants and contractors in the construction industry rely on during the construction life cycle.
It contains a series of measurements extrapolated from a buildings design, that identifies all the trade work of a construction project to enable the cost of all materials & labour for the associated work to be displayed in a simple and easy to read format.
It is typically separated by the description of the trade work with an accurate quantity to enable an estimator to input a rate that can be multiplied to provide a total cost for this item.
Item no Description Quantity Unit Rate Total
1 Concrete Finish 100 M2 $50 $5,000
A bill of quantities is usually prepared by a Quantity Surveyor or a Construction Cost Estimator before the sales and tender stage – often without any costs and only measurements – but can be provided with costs at a client’s request.
It is then issued to builders, contractors, and tradesmen to be populated with costs and estimates from for each item to get a highly accurate cost estimate for each item.
What types of Bill of Quantities are there?
There are many types of Bill of Quantities for various purposes. The two main formats of a BOQ:
This an elaborate form of Bill of Quantities typically provided for large scale construction projects – High Density Residential or Commercial Projects Greater than $5,000,000 or where many stakeholders are involved. Typically a BOQ (in Australia) must comply with the “Australian Standard Method of Measurements” as prepared by the “Australian Institute of Quantity Surveyors.”
Abbreviated BOQ or Builders BOQ
This is the most commonly used BOQ for Low Density Residential or Commercial Projects less than $5,000,000. It is a simplified version of a Bill of Quantities typically used for domestic applications where stakeholders are less stringent and clients primary focus is on time and cost and not quantities. An abbreviated BOQ does not have to comply with the “Australian Standard Method of Measurements”, but will generally be read in a similar format.
How does A Bill of Quantities differ to a Construction Cost Estimate?
A Bill of Quantities differs greatly to a detailed construction cost estimate. A BOQ contains a greater level of detail in comparison to a cost estimate primarily the method of measurement has more information in its descriptions and a greater level of data in its measurements and quantities. For example, where a bill of quantities would measure a concrete slab, it would provide multiple components for labour and materials, for example, the area of a concrete slab, identify the various thicknesses, as well as providing the volumes of material being supplied and the perimeters to enable a more educated estimate. All areas are separately documented to show the quantities of the different components. On the other hand, the construction cost estimate is far simpler, and would provide one description, quantity and rate for labour and the same for materials without emphasis on the different areas and components unless a greater cost difference would be applied.
Generally, a construction cost estimate is an estimate of costs as expected to be received from a builder, tradesperson or subcontractor. It would cover all measurements and costs in a simplified method with a primary focus of construction sequence and costs associated.
On the other hand, a builder, tradesperson or subcontractor should be able to quote from a Bill of Quantities without reviewing plans; there should be enough descriptions and quantities to understand what is involved in a project without the necessity to thoroughly review plans. However, a Construction Cost Estimate would need to be reviewed in conjunction with architectural and structural plans provided by the architect’s, designers and engineers to gain insight of how the costs and quantities were calculated and allowing a better understanding of the estimated costs.