The time has come for electrical contractors to gear up for BIM – and make the most of it. Chris Quirk of, Trimble MEP, explains how BIM can be combined with scanning and field positioning technologies in refurbishment and new build projects
In recent years we’ve been in receipt of considerable information and discussion around the subject of Building Information Modelling (BIM). However, many people less familiar with how other, complementary, technologies can be used alongside BIM to deliver tangible benefits to electrical contractors – even when refurbishing existing buildings.
Refurbishment is an important source of work for contractors, as so much of the UK’s existing building stock is here to stay for a long while yet. There may be a perception, though, that BIM is confined to new build projects. Thanks to advanced laser scanning techniques, this is not the case.
Whether working on a new-build or a refurb, 3D scanning enables contractors to make significant savings in both time and manpower expenditure while guaranteeing an incredibly high standard of accuracy. Data can be captured at a speed of up to 4,000 points per second and only one engineer is required to do the job where, traditionally, the task may have required two or even three. Remarkably easy to use and simple to setup, the scanners feature integrated self-levelling and positioning technology.
Crucially, the point cloud data can also be exported to CAD or BIM packages for estimating, detailing and collaboration with other disciplines.
To ensure outstanding accuracy scanners utilise on-board inclinometers to automatically level the instrument before scanning, while an integrated altimeter assigns elevation to each scan. Coupled with savings in time and manpower, this means that scanner converts typically see a very rapid return on their hardware investment.
BIM to Field
Once the contractor has an accurate model to work with, either created through scanning or supplied by the project design team, it makes sense to gain maximum benefits from it. One obvious area is in the layout of electrical and other services, again by combining BIM with other technologies. In this case a robotic total station (RTS).
Traditional layout of mechanical, electrical and plumbing (MEP) services requires a crew armed with the building drawings, a tape measure and sometimes a piece of string. Height or elevation is measured with a level, and a theodolite is used to measure angles. Errors are common with this traditional approach and can prove to be very costly. Another benefit of setting out with an RTS is that it can make working in awkward or tight spaces immeasurably easier – which is a blessing for MEP contractors in particular! Furthermore, because an RTS uses the same drawings or models as other trades remedial working, due to clashes, can be avoided.
The RTS tablet is loaded with a 2D or 3D building model. Site survey points generated in the model are used to easily locate the RTS on the project site. Once located the operator can select the points to be marked, such as hangar locations. The RTS will guide the user to the point (if using a stake) or using visual layout the RTS will mark the point with a highly-visible green laser. Each point is marked within a few millimetres of accuracy.
Another key feature of the RTS and BIM to Field is ‘Roundtrip capability’. The information of staked points is collected by the tablet software. This as-built data can be imported back into the original model ensuring it is kept up to date.
BIM is an example of how technology is coming to play an ever more important role in construction and those contracting companies that don’t embrace it will be left behind. When it comes to working with BIM it makes perfect sense to align it with complementary technologies that will help to improve project delivery, reduce financial risk and add value for the end client.