Most of an appraisal happens after the walkthrough, sitting in a car with the comps
Tagging along on an appraisal for a house under contract is instructive. A typical appraiser walkthrough on a split level might take nine minutes: a laser measurement of the main floor, photographs of every room including the inside the electrical panel, a quick look in the crawlspace, and back out. The real work often happens afterward, sitting with a laptop pulling comparable sales. An appraiser working through six pulled sales might throw out four of them: one a flip with an unpermitted finished basement, one backing a rail line, one sold to a relative. The walkthrough establishes what the house is; the harder part is arguing over which sales are genuinely comparable and what a below-grade square foot is worth on one street versus a similar one a few blocks over. The part clients often think they're paying for is the inspection-like walkthrough, but the part that actually decides the number is the grid of adjusted comparables built afterward. An appraiser who works without reference to the contract price, arriving independently at a number that happens to land above it, is doing the job the way it's meant to be done.
