What does “four or fewer units” mean for a home inspection?

It is the line where a residential home inspection stops and a commercial one begins. Both of the standards of practice that govern residential inspection scope themselves to small buildings: the InterNACHI Residential Standards of Practice applies to properties with four or fewer residential units and their attached garages and carports, and the ASHI Standard of Practice states that it applies to buildings with four or fewer dwelling units and their attached and detached garages and carports. So a duplex, a triplex and a fourplex all sit squarely inside a normal residential home inspection. A five-unit building and up does not. Above four units the applicable standard is the commercial one — InterNACHI publishes a separate International Standards of Practice for Inspecting Commercial Properties — which is a different scope, a different report format and a different basis for scoping the work. This is worth knowing before you shop for an inspector, for two reasons. First, it tells you honestly what you are buying: a residential standard is a non-invasive, visual examination of the accessible areas of the property and is not technically exhaustive, and a five-plex inspected under a residential standard is being inspected under a standard that does not claim to cover it. Second, unit count is what drives scope in this range, not square footage, because each dwelling brings its own heating, hot water, electrical and plumbing to evaluate on top of the shared shell. If you are looking at a building above four units, say so up front and we will scope it as a commercial engagement rather than quietly stretching a residential inspection over it. Tell us the unit count in the free instant quote tool below and the scope follows from there.