Building Inspections: Of What, for Whom?
Building inspections have become commonplace, almost universal tools used by potential buyers to evaluate their potential properties. As with most any service, a building inspection can be very useful; it can also be perfectly worthless. As a corollary, I remember when, ten years ago or so, I went shopping for my first computer and was advised to figure out what software I wanted and then buy the hardware to fit. That advice helped a little -- but I wasn't even sure of the difference between hardware and software and how the two interrelated. I made some stupid mistakes by not knowing, or bothering to find out, what questions to ask.
The same is true of building inspections; buyers often don't really know what issues to ask an inspector to address. And not all inspectors are equally experienced in the various local building typologies and so able to advise the client as to the questions that need to be asked, and then to answer them.
In the world of historic preservation, building inspections are usually called "assessments" if they are preliminary and "historic structure reports" if they are comprehensive. Both are useful for different purposes and both apply just as well to non-historic buildings. An assessment is typically performed to determine if the building is in any immediate danger of collapse, or to get a rough idea if the more comprehensive report is warranted. Assessments are not usually very expensive because they do not involve materials analyses, scaled drawings nor, in many cases, a written report. They can cost as little as $250.
If a building is any combination of large, old, or adobe, there is every likelihood that a more comprehensive report is a good idea. The older the house, the more need to look carefully behind the old plasters and into the old vigas. Another layer of complexity -- and potential problems -- is added if an old house has been added on to, possibly during several remodeling campaigns. In many of these cases, dissimilar materials are mixed resulting in the accelerated deterioration of the softer stuff, which is usually the original.
Needless to say, the equivalent of an historic structure report can be fairly expensive; we have conducted them for prices ranging from $2,500 to $15,000. That may seem a high price to pay for an inspection -- but consider the value of having the unknowns revealed in a property valued at a million or two. Consider also what such a service delivers.
A comprehensive structure report outlines the building's construction history based on available documentation, careful observation and inference. It then evaluates the condition of the materials, and does so in a manner that considers the building as a system of parts all of which need to work in concert. If there are subsidence problems, a geophysical report will be included. If there are stains on the walls or structural cracks, small cores can be removed in the footings and walls and the percentage of moisture measured. Similarly, rot surveys of all the wood in the building are conducted. The results of such tests provide the data necessary to both make recommendations for interventions, and provide a basis for estimating costs to repair. Such reports will always include images of the trouble spots -- "pathologies" in the preservation lingo -- including views of material deep within the walls or under the floorboards taken through an endoscope.
Finally, the report will outline specialized treatments, such as geosynthetic drainage systems, specially designed reglet flashings, and vapor-permeable plasters. Attachments will detail specifications for the needed repairs. Kind of like matching software to hardware.
If you are contemplating the purchase of a big, old adobe, consider the value of a structure report. If you are tending toward the more cursory assessment, ask yourself the questions, What that is useful will I learn from the exercise? and Who is going to benefit? It may be that the lesser cost benefits only the inspector.