For a recent issue of The Architects Journal, Dr Stephen Hamil was asked to provide a comment piece on "point cloud surveys". A copy of this is below....
On many new build projects, clients are now insisting on the use of BIM. This is utilised through the design and construction phases, and then passed to the client at hand-over. One of the big advantages to the client is in its application to facility management and the benefits are only increased when this is multiplied across a number of sites. For an owner of hundreds of buildings, having BIM digital records of exactly what materials they are made from can help maximise efficiencies in terms of running costs and renewing warranties. Such records also help manage maintenance, refurbishment and alteration work.
However, the percentage of a client's new build work can be small in comparison to that of managing existing facilities. This is especially true in the current economic climate. Point cloud surveys are one method of generating a BIM from an existing building. Through laser technology, it is possible to survey the spaces in an existing building to create a digital 'cloud' of geometrical points. All of this data can then be used to generate the geometry of the building. This is then imported into a BIM-enabled CAD package and the materials are identified. More 'meat on the bones' can be added to this BIM by adding detailed specification information to these materials.
The cost of a point cloud survey is now roughly the same as a traditional 2D survey. It is extremely accurate and generates a 3D model from which unlimited 2D 'cuts' can be taken - so it surely is the future?
I've heard it said that 'if a building is worth building it's worth building twice, once digitally during the design process and then again physically during the construction process'. Thinking about point cloud surveys, if there are design variations during construction, is it worth 'building' a third time? Before hand-over the building could be surveyed to create an 'as-built' model that can be compared with the design model, and provide a true digital record of the building.
Interestingly enough, this technology also hit the national news with this story on the BBC: Laser makes road crash image in 3D 
. A different application, but smart, 3D technology helping with efficiency in every day life.
Related reading from theNBS.com
Putting the 'I' into BIM
What does Building Information Modelling (BIM) mean for specifications?
