A bill of quantities is a document used in tendering in the construction industry in which materials, parts, and labor (and their costs) are itemized. It also (ideally) details the terms and conditions of the construction or repair contract and itemizes all work to enable a contractor to price the work for which he or she is bidding. The quantities may be measured in number, area, volume, weight or time. Preparing a bill of quantities requires that the design is complete and a specification has been prepared. [1]
The bill of quantities is issued to tenderers for them to prepare a price for carrying out the construction work. The bill of quantities assists tenderers in the calculation of construction costs for their tender, and, as it means all tendering contractors will be pricing the same quantities (rather than taking-off quantities from the drawings and specifications themselves), it also provides a fair and accurate system for tendering.
Bill of quantities are prepared by quantity surveyors and building estimators, and "Indeed the bill of quantities was the raison d'être for the development of quantity surveying as a separate profession." [2]
The practice historically of estimating building costs in this way arose from non-contractual measurements, taken off drawings to assist tenderers in quoting lump sum prices.
There are different styles of bills of quantities, mainly the elemental bill of quantities and trade bills
A contingency sum is an item found within a bill of quantities.
The item refers to unforeseeable cost likely to be incurred during the contracts.
There are two types of contingency sum. The first refers to a specific item, e.g., "additional alterations to services when installing said shower unit", where an item for alterations to existing services is not contained within the bill of quantities but some work is envisaged.
The second type of sum is where money can be allocated to any item, within the bill of quantities, in the same way as the above example or used as "additional work to be undertaken by the contractor, at the request of the contract administrator".
The first is usually approximated by the client’s PQS[ clarification needed ] and the second by the contractors QS[ clarification needed ] (or commercial manager).
Construction is a general term meaning the art and science to form objects, systems, or organizations, and comes from Latin constructio and Old French construction. To construct is the verb: the act of building, and the noun is construction: how something is built, the nature of its structure.
Design–bid–build, also known as Design–tender, traditional method, or hardbid, is a project delivery method in which the agency or owner contracts with separate entities for the design and construction of a project.
A general contractor, main contractor, prime contractor, builder (UK/AUS), or contractor is responsible for the day-to-day oversight of a construction site, management of vendors and trades, and the communication of information to all involved parties throughout the course of a building project. In the USA a builder may be a sole proprietor managing a project and performing labor or carpentry work, have a small staff, or may be a very large company managing billion dollar projects. Some builders build new homes, some are remodelers, some are developers.
A quantity surveyor (QS) is a construction industry professional with expert knowledge on construction costs and contracts. Qualified professional quantity surveyors are known as Chartered Surveyors in the UK and Certified Quantity Surveyors in Australia and other countries. In some countries such as Canada, South Africa, Kenya and Mauritius, qualified quantity surveyors are known as Professional Quantity Surveyors, a title protected by law.
Construction management (CM) aims to control the quality of a project's scope, time, and cost to maximize the project owner's satisfaction. It uses project management techniques and software to oversee the planning, design, construction and closeout of a construction safely, on time, on budget and within specifications.
A cost-plus contract, also termed a cost plus contract, is a contract such that a contractor is paid for all of its allowed expenses, plus additional payment to allow for a profit. Cost-reimbursement contracts contrast with fixed-price contract, in which the contractor is paid a negotiated amount regardless of incurred expenses.
A cost estimate is the approximation of the cost of a program, project, or operation. The cost estimate is the product of the cost estimating process. The cost estimate has a single total value and may have identifiable component values.
A specification often refers to a set of documented requirements to be satisfied by a material, design, product, or service. A specification is often a type of technical standard.
Construction bidding is the process of submitting a proposal (tender) to undertake, or manage the undertaking of a construction project. The process starts with a cost estimate from blueprints and material take offs.
When estimating the cost for a project, product or other item or investment, there is always uncertainty as to the precise content of all items in the estimate, how work will be performed, what work conditions will be like when the project is executed and so on. These uncertainties are risks to the project. Some refer to these risks as "known-unknowns" because the estimator is aware of them, and based on past experience, can even estimate their probable costs. The estimated costs of the known-unknowns is referred to by cost estimators as cost contingency.
Construction cost estimating software is computer software designed for contractors to estimate construction costs for a specific project. A cost estimator will typically use estimating software to estimate their bid price for a project, which will ultimately become part of a resulting construction contract. Some architects, engineers, construction managers, and others may also use cost estimating software to prepare cost estimates for purposes other than bidding such as budgeting and insurance claims.
Operational bills are a tendering document for estimating costs prepared by architects that describes a construction project in terms of the operations needed to build it. This form of document contrasts with that of bills of quantities in which such tendering and estimation is limited to the materials in the completed work. Operational bills have the advantages of enhancing communication between design and production, enabling realistic tender pricing, and making the preparation of critical-path analysis easy for the contractor.
Edward Skoyles was the first quantity surveyor employed in the UK to research costs and practices in the construction industry. He did his research from 1960 until 1984 at the Building Research Establishment. Among his research projects was developing a new type of tendering for construction projects called operational bills. He also started the study of the actual amount of waste in the construction industry, and investigated the varying methods of cost estimation practices used in different countries. His contributions are still widely discussed in the academic literature particularly upon operational bills, and building waste
Fast-track building construction is construction industry jargon for a project delivery strategy to start construction before the design is complete. The purpose is to shorten the time to completion.
The following is a glossary of terms relating to construction cost estimating.
Australian Construction Contracts govern how the parties to a construction contract behave and how the project manager and the contract manager administer the relationship between the parties. There are several popular standard forms of construction contracts that are currently used in Australia.
The CIOB Complex Projects Contract2013 was a form of construction and engineering contract, developed by the Chartered Institute of Building (CIOB). Its formal name was the 'Contract for Use with Complex Projects, First Edition 2013'.
A construction contract is a mutual or legally binding agreement between two parties based on policies and conditions recorded in document form. The two parties involved are one or more property owners and one or more contractors. The owner, often referred to as the 'employer' or the 'client', has full authority to decide what type of contract should be used for a specific development to be constructed and to set out the legally-binding terms and conditions in a contractual agreement. A construction contract is an important document as it outlines the scope of work, risks, duration, duties, deliverables and legal rights of both the contractor and the owner.
A lump sum contract in construction is one type of construction contract, sometimes referred to as stipulated-sum, where a single price is quoted for an entire project based on plans and specifications and covers the entire project and the owner knows exactly how much the work will cost in advance. This type of contract requires a full and complete set of plans and specifications and includes all the indirect costs plus the profit and the contractor will receive progress payments each month minus retention. The flexibility of this contract is very minimal and changes in design or deviation from the original plans would require a change order paid by the owner. In this contract the payment is made according to the percentage of work completed. The lump sum contract is different from guaranteed maximum price in a sense that the contractor is responsible for additional costs beyond the agreed price, however, if the final price is less than the agreed price then the contractor will gain and benefit from the savings.
Early contractor involvement (ECI) is a type of construction contract where the principal contractor is engaged at an early stage in a project to offer input into the design phase. It is in contrast to the design–bid–build model where the contractor is only brought onboard at the end of the design phase. The model allows the contractor to have an input in the design of the scheme and suggest value engineering changes. Studies have shown that savings of around 10% in construction phase time and 7% in cost are achievable through the use of ECI. The ECI model has become increasingly popular in the United Kingdom since the early 2000s and is also used in Australia and New Zealand.