A bill of quantities (BoQ) is a document used in construction projects to estimate the costs of materials and labor. It is prepared by a quantity surveyor and serves as the basis for tendering.
It allows easy comparison of contractor proposals. It also helps reduce favouritism and human error in the estimating process.
Definition
A bill of quantities is a document used in construction to provide detailed information on the material requirements of a project. It is typically prepared by a quantity surveyor or cost consultant to help contractors and building companies estimate the costs of materials and labour needed to complete a project. The information contained in a bill of quantities is generally based on drawings and designs along with detailed specifications. The items of work identified in the Bill of Quantities are then measured and priced to create a Schedule of Prices that can be utilised for pricing purposes.
The Bill of Quantities is a vital part of the tendering process for any construction project. It helps to ensure that all contractors are bidding on the same work and materials, which can help to keep the overall project costs under control. It also allows building contractors to compare their tenders with other suppliers’ offers.
The Bill of Quantities can be based on a number of different measurement units, including length, area, volume, weight or time. It can also include a rate that is applied to the work item. This can be useful for example when the quantity of framing to be installed cannot be measured at this stage but the contractor can supply a rate per lineal meter or square metre.
Meaning
The Bill of Quantities is a document that provides details about the materials and labour required to carry out a construction project. It is usually prepared by a quantity surveyor and is an essential part of the tender process. It helps contractors to estimate the cost of a project and allows them to compete fairly. It also reduces the chances of miscommunication and misunderstanding between parties.
A BOQ includes a list of work items and their associated quantities along with rates. These rates are calculated based on the cost of each item in the form of number, length, volume, area, or weight. The document also contains a contingency sum, which is an amount that covers unforeseeable costs. A contractor can use the information in the BOQ to calculate their price and bid for a contract.
A bill of quantities is generally created by a process called ‘taking off’, which involves identifying elements of the construction works that can be measured and priced. The method used to prepare a bill of quantities is dictated by the rules of measurement that apply to the project. These rules can be found in the New Rules of Measurement (NRM) that replaced SMM7 on 1 January 2013.
A BOQ is generally prepared by a cost consultant or quantity surveyor, who are often associated with the engineering firm that was responsible for the design. This ensures that a neutral party is preparing the document and minimizes any disputes.
Origin
Bills of quantities are prepared by a cost consultant (quantity surveyor) and form the basis for pricing construction works. They provide project-specific measured quantities of items identified in the drawings and specifications for a built asset such as a building. These are generally used to request bids from contractors and as the basis for comparing contractor proposals.
Typically, the work in a bill of quantities is divided into appropriate building elements and items are grouped within each element to reflect the actual order in which the works would be carried out on site. For example, excavation and filling is grouped together under the heading “Excavation and filling”. In some instances, a provisional or approximate bill of quantities may be prepared where the design is incomplete. This type of bill can be used to reduce the tender documentation process and enable the contractor to commence work earlier. However, this will result in a higher number of variations during construction and less price certainty when the contract is awarded.
A detailed BoQ should clearly outline the scope of work in a clear and concise way. It should also include accurate unit prices for all materials and labour. This will help to avoid any misunderstandings between the client, contractor and quantity surveyor. Additionally, a well-prepared BoQ will reduce the time taken to prepare tenders and can assist with more competitive bidding.
Usage
A bill of quantities is a document used to estimate the materials and labour required for a construction project. It is prepared by a quantity surveyor or cost consultant and serves as the basis for pricing the work. It is often included in the tender documentation sent to contractors who wish to quote for the project. It is also useful for comparing the prices of different contractors, and can help to prevent disputes over differences in interpretation of the tender documents.
The most important thing to remember when preparing a bill of quantities is to use standard methodology. This will prevent confusions and ambiguities that can occur due to differences in interpretation of pricing and quantities. Moreover, it will save time and effort by eliminating the need for re-work. Similarly, it is important to have an accurate and clear description of each item in the BOQ.
A bill of quantities is usually prepared once the design is complete, but it can be updated as the project progresses. In some cases, the project is tendered with incomplete designs, and in this case, a preliminary bill of quantities can be used to estimate the scope of the works. A preliminary bill of quantities is based on the construction drawings and the specification. It contains a list of items with brief descriptions and their corresponding rates.