A Bill of Quantities (BoQ) is an essential construction document that helps to make the tendering process more uniform and pricing more precise. It also helps to ensure cost control and project management during construction.
It is prepared by a quantity surveyor and provides a list of quantities with detailed descriptions. It also includes the unit rates tied to these work items.
Definition
Bill of quantities (BoQs) are an integral part of construction project management and help to improve efficiency, transparency, and cost control. However, creating one requires a thorough knowledge of industry standards and best practices. If you’re unsure of the process, it’s best to consult with a professional quantity surveyor or construction cost consultant for guidance.
A provisional sum is an amount inserted into a contract sum analysis to cover certain items of work in building contracts that cannot be accurately defined, detailed, or valued at the time tendering documents are issued by the employer. This could be because the scope of the work is not yet fully understood or that it’s difficult to specify based on the information available.
The process of preparing BoQs begins with collecting the necessary project documents, including architectural plans, engineering drawings, and specifications. Afterward, the project manager and other team members should review these documents thoroughly and itemise all materials and labour required. This will allow contractors to prepare precise cost estimates and submit transparent bids for the project.
For complex projects, a BoQ may include activities that are dependent on each other. For example, excavation and blinding must be completed before foundation footing construction can begin. In such cases, it’s important to use a network analysis approach to determine the order of activities. This will ensure that the correct amount of material and labour is used and minimize any delays in the project schedule.
Scope of work
Proper documentation is the lifeblood of construction projects. It enables accurate measurement, cost estimation, and project control. While many documents are required, two types stand out as critical for the construction process: a Bill of Quantities (BoQ) and a Schedule of Works (SoW). Choosing the right document depends on the client’s preferences and requirements. It is important to clearly communicate the chosen document with stakeholders to ensure that it meets expectations.
A BoQ is ideal for large projects that require detailed specifications and costs. It is usually divided into sections based on activities, operations, and sequences of work. It is also possible to divide the BoQ into sub-sections based on the work items that require prior completion of other work. This helps to simplify the understanding of the work and reduce the risk of misunderstandings.
A SoW, on the other hand, is a less-structured document that provides less granularity in cost breakdowns. A SoW may be used when the scope of works is not fully defined or if it’s decided that a full, detailed BoQ is not necessary at the tendering stage. A SoW should be accompanied by an estimated bill of quantities and a dayworks section that allows contractors to insert their preferred mark-up for overheads and profit. This can help prevent disputes over the cost of additional works and promote fair competition.
Preliminaries
A provisional bill of quantities is a key component for the construction project. It helps the contractor determine the materials, parts, and labor required for the project. It also helps the contractor plan and schedule activities in a manner that minimizes cost. The process of preparing a provisional bill of quantities can take up to six weeks. However, if the contractor uses proper calculations, the process can be completed in less time.
This type of bill of quantities is a document that contains approximate quantities and is subject to re-measurement. It is usually used if it is not possible to prepare a firm bill of quantities at the tender stage. It is useful because it reduces the tender documentation period and allows the contractor to start work earlier.
In addition to the measured quantities, a provisional bill of quantities includes a schedule of dayworks rates. These are rates that a contractor can use to competitively tender for certain work. These include costs such as site accommodation and set up, erection of scaffolding, craneage, power, and other items that are not included in the rates for the measured work items.
The main purpose of the provisional bill of quantities is to provide a clear and concise record of the scope of works. It is also used for preparing payment applications and as a reference in case of disputes.
Post-contract stage
In the construction industry, Bill of Quantities (BoQ) is an essential tool for tendering and pricing. It also helps in record-keeping and creating a fair agreement among all parties for contracting purposes. Its functions may vary depending on the type of project and its requirements. However, there are some basic functions that are common to all types of BoQs.
The first step in preparing a BoQ is to collect all the relevant project documents, including architectural plans and engineering drawings. The next step is to review these documents thoroughly and itemise all items required for the project. After this, the items are categorized as either materials or labour. Then, a percentage for contractor overheads and profit is added to each item rate. This percentage can range from 2.5 to over 25 percent.
Once the BoQ is prepared, it can be used to prepare a schedule of rates. Then, all the item rates are added up to produce the bid price for each work item. The item rates include the cost of materials, labour, and equipment. Moreover, the BoQ also includes other project expenses like transport, inspection fees, and insurance costs.
The preparation of BoQs requires substantial man-hours and a high level of skill, which is why it is important to produce them correctly the first time around. A well-prepared BoQ will save you time and money in the long run, as it will make the tendering process more uniform and the pricing more precise. Furthermore, it will reduce claims and disputes between contractors.