Architects, like me, who work on existing buildings, spend months and probably years of their professional life trying to capture the existing conditions prior to starting their new projects. Now with the advent of laser scanning which can provide us with accurate documentation in a fraction of the time, the question is no longer do we need to scan or not, but rather how early in the process should the architect get their hands on the scan data.
That question has ramifications not just on the work itself but also on the traditional contractual relationships. Scanning is frequently confused with the traditional survey contracts of the past. The scanning scope needs to be owned, defined and managed by the Architect. This ensures they and the owner will get optimal use of the scan data and have a tool that helps reduce liability. An exact 3D archive of the project allows the Architect to travel back in time to the date of capture and verify any condition. Additionally, scope changes can easily be accommodated based on the extensive 3D database.
In my own experience as a novice in using laser scanning I focused on using it as part of creating accurate construction documents. Sometimes we contracted for it well after we started pre-design or even as we were starting to work on design. In some cases, not until after we have started design and realized we were short on original construction documents, or realized the existing documents were grossly inaccurate.
The revelation of what we were missing came to me on a project with a pending law suit on which I served as an expert witness. The issue at hand was the condition of the state of disrepair of bricks on a historic building that had undergone a conversion. Parties could not agree on the degree of deterioration of the grout joints and the brick exfoliation and therefore could not agree on a settlement to avoid going to court. That disagreement persisted for more than a year and a half with no hope in achieving a successful mediation. That is until we scanned the front elevation of the building. With the help of our service provider we were able to analyze the condition of the bricks and mortar through the use of deviation maps and successfully brought about an agreement between parties that was founded on empirical data.
On another project that was concurrently in progress we had to determine whether the new cladding system we wanted to utilize in our design could be accommodated by the existing framing condition. The buildings foot print and height made it impossible to accurately survey the stud positioning using conventional methods. We used laser scanning to capture the positioning of the framing members after demolition was completed on a large mock-up area. We were then able to accurately determine the tolerances and confirm that we could move forward with a less expensive approach, saving the client hundreds of thousands of dollars.
These two projects further changed my approach on the timing of scanning services. It became clear that scanning can add great value for forensic investigations of buildings when a dispute arises over construction defects. On other buildings with no disputes, I can diagnose problems that may impede design or ascertain the viability of a concept during pre-design.
Numerous other experiences since have me convinced that getting the scan data on existing buildings before starting the investigation/evaluation or pre-design maximizes the benefits on all levels leading to better diagnostics and design with tangible savings many times the cost of the scanning service.
Scan First and Think Later, while not exactly true, this phrase represents how I value scan data of existing conditions.