- Project plans
- Project activities
- Legislation and standards
- Industry context
- Specialist wikis
Last edited 15 Dec 2020
A development of the elemental cost plan of estimating construction project costs, approximate quantities form part of an approximate quantities cost plan which represents a first attempt to measure defined quantities from drawings (or to ‘take them off’)
An approximate quantities cost plan is part of the iterative cost planning process and is a development of the elemental cost plan. Unlike the elemental cost plan (in which the cost of elements is broken down from the overall construction cost, based on the experience of the cost consultant and known costs of similar completed projects), the approximate quantities cost plan is a first attempt to measure defined quantities from drawings. In effect, it is a costed approximate bill of quantities.
The approximate quantities method is regarded as being more accurate and reliable than other estimating methods in showing where costs are distributed. In particular, it draws to the attention of designers those elements of the design that are standard and those that are not and which, as a consequence, may be more expensive.
Unlike the elemental method, the basis of the approximate method of estimating is the grouping together of diverse, combined items under a rate (known as a composite rate) which is calculated by combining the individual prices of the components in the group. Because the items grouped together have the same dimensions (whether in metres or square metres, or perimeter and area), it allows those items to be measured at the same time.
The approximate quantities cost plan can form a solid base for an effective value engineering exercise. However, it should be accompanied by a schedule of assumptions made and perhaps a cash flow projection. A pre-construction whole-life cost plan may also be prepared.
 Related articles on Designing Buildings Wiki
Featured articles and news
Complete list of 2021 winners now available.
Recognising past and present role models for the future.
So why not write something?
LETI publishes guidance for energy efficient home retrofits.
Predictions about adequate post-pandemic IAQ in non-domestic buildings.
Government publishes plans to 'build back greener'.
The contentious nature of claims associated with cladding, fire safety and EWS1 forms.
ECA comments on low-carbon heating systems initiative and Heat and Buildings Strategy.
Cinders and other forms of domestic rubbish created filth but also generated great wealth.