- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 26 Feb 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
Developments in the Future Homes Standard.
An American chimney feature with a colourful past.
Homes based on need, not ability to pay.
Historic England adds 216 entries to the 'at risk' register.
Will cycling and walking provisions be preserved?
Assembly point levels range from relative to ultimate.
Signs are pointing to a recovery for the construction industry.
Campaigning to change perceptions about American Brutalism.
Sprinkler head configurations can prioritise people or property.
Report from The Carbon Project reveals shortcomings and recommendations.
Advice on how to join the electrotechnical profession.
BREEAM Building Back Better briefing paper provides initial guidance.
CIOB conducts global search for best built environment picture.