The test tones (usually impulses of some sort) that are emitted are a big part of the effectiveness of echolocation. Also, the higher the frequencies that are used the more resolution one gets. Unfortunately this BBC article is very thin on information about the specifics of the method.
This is very cool and probably has potential for modeling, etc., but currently the most accurate 3D modeling can be done with a scanning laser. (IMO) These laser scans can be imported directly into AutoCAD and several other 3D modeling programs.
You can see examples of this on many television programs, ie; laser mapping of the Titanic & scanning the internal structure of caves... I have seriously thought about having some of my clients get me a 3D scan of their facilities (bare warehouses, etc) to help me get all the measurements right. [some people just can't use a measuring tape ]
agreed - getting a LIDAR scan of the space will give you the most accurate set of physical measurements, and if you have the resolution high enough, you can get the pipes, wires, etc which may impact the use of the space included so you can plan sooner rather than later :-) LiDAR News - Home