Representative Observations

A walk-through cannot open every tenant suite or inspect every window. E2018 allows the field observer to observe a reasonable sample of repetitive systems and components and to extrapolate conditions and costs from it, and it requires the report to disclose the extent of the observations so the reader knows what the sample was. "Restrooms: three of six groups observed; the two on the second floor were original 1985 construction" is a representative observation with its extent stated.

Agency programs turn the allowance into a rule: Fannie Mae's Form 4099 prescribes how many units to inspect by property size and requires the sampled units to be listed. Under plain E2018 the consultant chooses the sample and states it.

The corollary is that a system not sampled at all is not observed, not extrapolated. Suites the tenants would not open are listed as areas not accessed, not assumed to match their neighbours.

Related: walk-through survey, readily accessible, limiting conditions.