An elemental bill of quantities is a pricing document that provides an estimate of the cost of the construction works. It consists of measured quantities of materials and labour derived from project drawings, specifications and schedules.
It can be used to compare contractor proposals and select the best bid. It also helps with scope progress monitoring during the construction phase.
Definition
The Bill of Quantities (BoQ) is a construction document that provides a detailed breakdown of the materials, labor and equipment required for a project. It is a critical step in the design and costing process, and can help prevent overspending. It also helps to ensure that all stakeholders have a clear understanding of the project requirements and costs.
The BoQ is usually prepared by a quantity surveyor, and is made up of measured quantities of construction work derived from the project drawings, specifications and schedules. It is a key component of the cost estimation and tendering process, and helps to improve communication between the client, the contractor and the construction team.
A BoQ is typically arranged in trade order, with each trade description being a separate section and priced individually. This allows for the description of the various items of work to be compared against the tender prices, and is often used as a checking system on the tenders received.
Elemental BOQs are generally performed at an early stage in the development of a project, and can be updated alongside the evolving design. This enables the budget to be managed throughout the project and can avoid designing outside of the budget, which can save huge sums of money during the build. Unlike the more superficial area or unit methods, an elemental BOQ is broken down into major elements of the building for example; site preparation, substructure, superstructure, external walls, internal walls, windows & doors etc, making it easier to identify savings opportunities.
Functions
There are several important functions of an elemental bill of quantities. One is that it allows standardised and equitable tendering. By ensuring that all contractors are pricing the same specified materials and work, it is easier for owners to compare bids and assess their value. It also reduces the time spent on tendering and estimating by avoiding errors and misinterpretations.
Another function is that it enables the use of standardised construction methods and analysis, which will help to control costs and improve quality. It is also a useful tool for monitoring project progress and cost to ensure that the budget is on track. It also allows for the identification of potential cost risks and contingencies.
Finally, it serves as a reference document for the calculation of construction costs. This can be done by comparing the estimated costs against the actual costs at various stages of the project.
There are several different types of BoQs, including itemized, abstract, preliminary, and trade BoQs. Each type has its own purpose and function. Itemized BoQs list all the items and their quantities needed for a project, while abstract and preliminary BoQs are broader and provide an overview of the requirements and costs of a construction project. A trade BoQ is organized by the various construction elements, such as foundations, walls, and roofs. Finally, an approximate quantities cost plan is a development of the elemental bill of quantities that provides a first attempt to measure defined quantities from drawings.
Scope
An elemental bill of quantities, also known as a cost plan, is a list of measured quantities of materials, labour and equipment derived from project drawings and specifications. The document is prepared by a Quantity Surveyor or a Construction Cost Estimator and is used primarily to ascertain project building costs. It can be a useful tool for tendering contractors as it provides them with a standard set of information to price against. The document is typically drafted after the design stages, with the intention of speeding up the tender documentation process. It can be created as a provisional, approximate, or detailed bill of quantities.
The main advantage of an elemental bill of quantities is that it enables all contractors tendering for the contract to price on the same basis, and this helps the owner to negotiate the lowest possible price for the work. However, it is important to remember that any variation in the quantity of works can lead to re-measurement, which will entail additional costings and redrafting of the cost plan.
Another potential disadvantage of an elemental bill of quantities is that they are often based on traditional construction methods and may not reflect the cost implications of more innovative or specialised building techniques. In such cases, a more flexible approach to cost planning such as parametric estimating might be a better alternative.
Format
An elemental bill of quantities can be presented in a number of different formats, each of which caters to particular requirements. For example, it can be arranged in trade order and have each description with its price listed or, as is more common, the descriptions can be grouped together into a general summary for each trade. It can also include “rate only” items where the quantity is not specified but instead a rate is quoted for each item of work.
Regardless of the format, an efficient elemental cost plan is beneficial to contractors and project managers alike. It enables all contractors to submit competitive bids based on unified quantities and therefore reduces variation in pricing. It also facilitates transparent tendering processes and promotes a consistent analysis of costs between bids.
Another advantage is that it can be updated as the design progresses, ensuring that all expenditures are accounted for at each stage of the development. This allows you to avoid designing outside of your budget, which can ultimately save you huge sums of money throughout the project lifecycle. An elemental cost plan can also be used to demonstrate the feasibility of a construction project, for example when presenting plans to secure funding from investors or banks. Having your own Quantity Surveyor (QS) prepare an elemental cost plan for you is recommended as they can provide the best insights into construction technology, building materials and planning details.