While we normally measure buildings to generate our drawings, sometimes we work from sets of two-dimensional architectural drawings. In this case, the challenge was to work from a set including exterior elevations, plans and a section in order to create what is called a building information model. The drawings were done in the late Seventies, when people were drawing by hand as opposed to using CAD, meaning that dimensions and alignment were not always accurate. Even now, with CAD as the industry standard, drawings are still prone to error when it comes to coordinating multiple two-dimensional views of a complex three-dimensional shape
With the arrival of new CAD software that automatically makes all 2D representations part of a 3D model that contains all the information about a project, known as a building information model, if alignments are off there will be error messages and glaring mistakes in the model. Take this process rendering for example. When the vertical stone element was extruded based on the two-dimensional hand drawings we were given, all of a sudden other walls began to intersect that stone element. That was impossible in the 2D era. The rendering also shows the limitations of building information modeling (BIM), because if you compare it to the photograph the pitch of the roof is different. The BIM model has an obvious hole in it where the roof is supposed to angle down to the right and overhang toward the adjacent slope. Overall, BIM is a great way to make sure that all of the two-dimensional drawings line up perfectly, because they are all based on one 3D model. Often, however, in order to do things accurate to the way they are (supposed to be) constructed, it requires that the software ‘understands’ whether or not an angled surface is supposed to be a roof or a wall, for instance. In the real world, BIM is the best thing ever for repetitive buildings made of standard parts. Customization in the software (Revit in this case) is still cumbersome for projects that require uniquely crafted details in their construction.