Those incomplete blueprints
Most often we will recreate site plans based on some very old and incomplete blueprints. They will usually stop exactly at the property line, as on right.

Multiple sources
Then we need to fit together information from multiple sources. With maps and aerial photographs we can complete them, as on right. Or by fitting together two or more blueprints, as for shopping center below.

Floor plans
The source for our floor plans can come from blueprints, previous brochures, scan, or from CAD files from architects (like AutoCAD), usually in DXF format. It is necessary to stick to the basics, and to simplify overly detailed floor plans (below).