The first step in an appraisal assignment is identifying the problem to be solved – the "who," "what," "when," and "where," if you will. While no one will argue the importance of location on real property's value, size factors heavily into the value problem. Figuring out a building's size is an important step in defining the "what" part of the problem.
So, where do we get the answer? In a perfect world, every property would have recently been surveyed, and we would already know the building's dimensions and areas. Since most appraisers don't work under such utopian conditions, we have to just get out there and measure ourselves. Given that my beloved Rio Grande Valley seems to have two basic seasons – hot, humid, and windy – or cold, wet, and windy – any tool that can expedite the process is welcome. There are other issues that make measuring with traditional measuring tools impracticable or sometimes downright impossible: planters, trees, and fenced-off areas.
About ten years ago, I started measuring with a Leica Disto. While it's certainly not perfect and has several shortcomings, I find that it provides accurate and quick measurements. With this tool, if I can find something to bounce a laser beam off of, then I can know the precise distance to that something. This proves its worth when measuring places I can't gain physical access to in order to hook up a tape measure. For example, I often find areas in warehouses that are inaccessible due to stacked pallets, fenced off loading docks, or parked semi-truck trailers. It is usually possible to find a void to shoot the laser through and obtain an important measurement that would otherwise require guesswork.
During my site visits, I have consistently heard more comments and questions about the laser measuring tool than any other topic. These usually come about while I am measuring things that would would prove impracticable: things like eave heights, clear-span heights, or high-ceiling heights.
As to the shortcomings, I usually get a reading off of most building materials up to 80 feet or so. Beyond that, I have to use a reflective target, which I cut to fit in my back pocket. These can be adhered to a downspout, electric meter box, or the corner of a building with removable poster tack and will give me a target that will produce reliable readings over distances as far as 600 feet.
After ten years of reliable service in the field, this tool has become an indispensable part of my workflow.