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APC Competencies - Measurement Tools by Jen Lemen

APC Competencies - Measurement Tools by Jen Lemen

This article discusses the Measurement technical competency, which relates to the data capture and measurement of land and property. Specifically, we will be looking at measuring tools, limitations and how to measure accurately. It is essential reading for RICS APC and AssocRICS candidates on a wide range of pathways, including Environmental Surveying, Geomatics, Planning & Development, Land & Resources, Commercial Real Estate, Corporate Real Estate, Facilities Management, Residential, Valuation, Building Control and Building Surveying.

What measuring tools are there?

Surveyors will use a variety of measuring tools, the most common being the laser measurer or laser distometer (disto). A laser disto works on the basis of measuring how long it takes the laser pulse to be reflected from a surface. For a typical laser disto, they have a measuring accuracy of +/- 1.5mm and can cover distances of up to 200m. Some more advanced devices also allow for the measurement of areas, volume and triangulation.
Tape measures are also a useful measuring tool, both in cloth and steel tape format. They are typically used for measuring narrow or complex areas, or where it is not possible to use a laser (e.g. bright sunlight). A measuring rod could also be used for tight areas or to measure behind an occupier’s fit out (without causing any damage or being intrusive).

When measuring land, other tools may be better suited, such as a trundle wheel. Mapping software, such as Promap or Google Maps, could also be used to cross check site areas.

Surveyors should always try to take a floor plan to site for annotating measurements. Ideally, this will be a scaled plan so that measurements can be cross checked using a scale ruler. If this is not possible, then a neat and tidy floor plan could be sketched on site using graph paper or floor plan software/app.

What are the limitations and sources of errors when using these tools?

Surveyors must be aware of the limitations of their measuring tools. Here are some common limitations:
  • Lasers do not work well in bright sunlight, as it can be hard to see the laser beam. Using a long tape measure can overcome the issue or by shadowing the target area
  • When using a laser to measure to a dark surface, the measuring time can increase leading to inaccurate measurements. Taking a sheet of A4 white paper to site can be used as a measuring target
  • Lasers may be inaccurate when measuring to colourless liquids, glass, styrofoam, permeable or high gloss surfaces
  • Cloth tape measures can be inaccurate if not fully stretched or if they are over-stretched
  • Steel tape measures may not be long enough for certain distances
  • Measuring software may be less accurate given that it is hard to pinpoint the exact boundaries or surfaces to measure to online
  • Photocopied scaled plans can be distorted which will affect the scale of the plan. This can be overcome by using check measurements to confirm the accuracy of the scale specified on the plan

How can I calibrate my laser disto?

It is possible to check typical accuracy and calibration for a laser disto by following the Leica guidance. This involves establishing a constant baseline, taking at least 10 measurements from a fixed point and carrying out a number of calculations. These results should also be recorded in a log.

It is also possible to send the laser disto away for re-calibration. Typically lasers become inaccurate after being dropped and may show an error (e.g. 256) when they become inaccurate.

How can I measure accurately?

Accurate property measurement is essential to provide accurate advice to clients. Think about it – if you are valuing a large, high value building, then even a small inaccuracy in floor areas will result in a larger discrepancy in the overall value. The same goes for measuring a property that is due to be refurbished – being out by even a few centimetres may mean that the proposed design doesn’t fit into the finished building.
Here are five ways to measure accurately:
  • Take check measurements, if they differ – do it again
  • Check measurements taken on site against scaled floor plans
  • Check that you are measuring to the correct surfaces, e.g. not the occupier’s fit out
  • Take the RICS guidance to site to ensure you know what to include and exclude in the appropriate basis of measurement
  • Take your time, measurement needs a logical and diligent approach! Taking a second person with you can help to hold a target for the laser, the other end of a tape measure or to annotate the measurements on a plan. It also avoids the need for lone working


At level 2, you need to be able to confidently and accurately measure buildings or land using a variety of devices. This includes being aware of potential limitations and sources of errors, in addition to measuring in accordance with RICS Property Measurement (2nd Edition).

If you are in doubt about your own measurement skills, why not use a practice exercise to test yourself out? Find a room in your house or office, take your measuring devices and annotate or sketch out a floor plan.

Follow the guidelines in RICS Property Measurement (2nd Edition) and ensure that you make appropriate inclusions and exclusions. If you can compare these to a scaled plan to check your accuracy, even better. Good luck!

About the author - Jen Lemen BSc (Hons) FRICS 

Jen has extensive experience in providing training services to students, RICS AssocRICS, APC and FRICS candidates and corporate clients, together with academic experience as a Senior Lecturer at the University of the West of England, Lecture at the University of Portsmouth and Associate Tutor at the University College of Estate Management. Her RICS assessment experience includes sitting on final APC interview panels, APC appeal panels and being a lead APC preliminary review assessor.

She has also written published articles in Property Week, ACES Terrier, RICS Modus and the RICS Property Journal. She also writes a regular APC column in Estates Gazette Brick & Mortar podcast series with Sarah Jackman and is a contributing author to the Health & Safety section on RICS iSurv.

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