Measured quantity
Quantity is a measurement of a physical entity in units that depend on the nature of that entity. Therefore, quantity indicates how much of something exists, existed or will exist.
In construction, ‘measured quantities’ typically form part of a bill of quantities (BoQ) and indicate how much of something will be required to construct a building or part of a building.
Usually prepared by a quantity surveyor (QS), the BoQ provides project-specific, measured quantities of the items of work identified by the drawings and specifications (which form part of the tender documentation). For example, in a traditional building, the BoQ will contain measured quantities for each item that goes to make up the final construction e.g bricks, doors, ironmongery, floor tiles, roof slates, etc. This means that potential tenderers know exactly how much of a given quantity will be required for the work and so they can price for it. This creates a level playing field as all tenderers are pricing for the same measured quantities which allows the client to make easy comparisons between the bids.
Measured quantities are typically expressed in number (e.g door handles), length (e.g handrails, kerbs), area (e.g floor tiles, plaster), volume (e.g concrete) or weight (e.g gravel).
When prices have been entered by a tenderer beside each measured quantity in a BoQ, this constitutes the tenderer’s offer.
Not providing measured quantities would require that the various tenderers on a project ‘take off’ the quantities themselves. With numerous tenderers with possibly different methodologies, as well as human error creeping in, the quantities taken off would vary, thus making the client’s job in comparing the tenders that much harder.
The New Rules of Measurement (NRM) are published by the Royal Institution of Chartered Surveyors' (RICS) Quantity Surveying and Construction Professional Group. They provide a standard set of measurement rules for estimating, cost planning, procurement and whole-life costing for construction projects. Adopting a standard methodology such as NRM facilitates consistency and benchmarking and helps avoid disputes.
NRM is a suite of documents, comprising three volumes; NRM1, NRM2 and NRM3.
Fore more information see: New rules of measurement.
In some circumstances, it may be difficult to determine exact quantities, for example early in the development of a project. In this case approximate quantities may be estimated. These should be accompanied by a schedule of the assumptions made in determining the approximate quantities.
For more information see: Approximate quantities.
[edit] Related articles on Designing Buildings Wiki
- Approximate quantities.
- Bill.
- Taking off construction works
- Bill of quantities breakdown structures BQBS
- Types of bill of quantities
- Standard Method of Measurement SMM7
- Preliminaries in construction
- Schedule of rates for construction
- Bill of quantities software
- Tender documentation for construction projects
- Approximate bill of quantities
- How to take off construction works
- Specification for construction
- Advantages of a bill of quantities
- New Rules of Measurement
- Typical tender process for construction projects
- Priced bill of quantities
- All-in rates
- Common mistakes in bill of quantities
- Bill of quantities v Schedule of rates
Featured articles and news
Mental Health Awareness Week with ABS
Architects Benevolent Society programme of activity.
CLC publishes domestic retrofit competency framework
Roadmap of Skills for net zero.
May 13-19: Moving more for our mental health.
Understanding is key to conservation.
Open industry engagement survey seeks responses
Institutions and the importance of engagement.
National Retrofit Hub unveils new guide
Digital Building Logbooks and Retrofit: An Introduction.
Top 50 firms awarded 52bn of projects in the last year
New engineering data shows.
Enhancing construction site reporting efficiency
Through digitisation and the digital revolution.
Noise in the built environment
BSRIA guide TG 20/2021.
17,000 people suffer conditions as a result of exposure to excessive noise at work.
Turning down the noise: Auditory health
A pervasive risk with far-reaching consequences.
Getting the most out of heat pumps and heating
How heat pumps work and how they work best.
Plumbing and heating for successful retrofit and renovation
Low temperature underfloor systems and heat pumps.
Cost-of-living crisis and home improvement plans
Starting on the right footing and top tips for projects.
Delays on construction projects
Types, mitigation and the acceleration of works.
From Chaucer to Fawlty Towers.
Electrotechnical excellence, now open for entries.
Net zero electricity grids BSRIA guide NZG 5/2024
Outlining the changes needed to transition to net zero.
CIOB Global Student Challenge 2024
Universitas Indonesia wins for second year running.