It is estimated that the world wide construction industry is $4.6 trillion dollars, over $1 trillion in the US alone. However, upto 80% of that construction is performed in the built environment. Adaptive reuse, tenant improvements, renovations and the like dominate especially in older cities and especially in Europe. The big question is how to take advantage of all the benefits of BIM in the built environment. There are different technologies at use that I believe are more complimentary than competitive.
Graph Paper and Pencil
Graph paper and pencil is still the most used technology today. Why? There is little or no technology to learn much like going out for a run where all you have to do is put on your sneakers and head out the door. The problem is it is time intensive. The process involves drawing the building and then placing measurements on each architectural feature. When thatis completed you have to translate all of that onto a CAD workstation. Inevitably there are missed measurements and the surveyor/drafter will need to revisit the site, or make an educated guess at what is happening inside the building making it time intensive or error prone. More often than not these as-builts get a VIF (Verify In Field) stamp which then puts the onus on the construction manager to get it right in the field causing work delays as they repeat work that has already been done.
Point to Point Laser Technology (PPLT)
This technology translates laser range finder data directly into a CAD or BIM enabled work stations. This allows the user to build models or capture a building geometry in real time while in the field. By building in real time the user knows if the building is being captured correctly. With real time feedback they know if a room is dimensioned correctly simply by looking at the model, and an incorrectly drawn room will not close. The relationships between rooms are captured and the envelope of the building is determined and drawing on site. Additionally, the user walks out of a building with a model that is close to complete needing much less post processing than other methods.
Equipment exists today that will scan buildings creating a dimensionally correct point cloud of a building. Users can query the model to develop features and their relationships. While we dream of the day when these scans can be converted instantaneously into a BIM model the reality today is that intensive post processing is needed to turn them into a model than can be used inside a BIM package. After collecting the data the operator needs to take cross sections of the building in multiple views to bring into a BIM program. They use these sections as backgrounds to build a model so a lot fo tracing needs to be done, inserting another user intensive process into BIM creation. Uses for this technology can be excellent where data collection is difficult or MEP intensive projects. There is excellent case studies (I will find them later and post them) where when using this technology to capture an MEP intensive project like an oil rig retrofit minimized or even eliminated reworking on the site. That all the piping and equipment was designed and engineered off site and fit perfectly. The ROI can be immense when you imagine a full construction crew on site, and the as-builts pay for themselves, many times over.
The Right Tool for the Job
When starting a job a surveyor, architect, engineer, etc. must decide what technology to use based on the job. Many times what is needed is the correct geometry of the building is needed, in this case, PPLT might be best employed other cases laser scanning is needed and in smaller jobs even graph paper and pencil might be best employed. Most importantly is to create dimensionally correct data so everyone working downstream can work more effectively and problems or any other issues are solved digitally rather than on site.