What happens during a home inspection, and what stops one

The short answer: a visual examination of what is readily accessible

A home inspector performs a visual, non-invasive examination of the readily accessible systems and components of the house, operating the normal operating controls and opening readily openable access panels, and then writes a report describing what they found and naming what they could not reach. The ASHI standard defines inspect precisely that way: “The process of examining readily accessible systems and components by (1) applying this Standard, and (2) operating normal operating controls, and (3) opening readily openable access panels.”

Everything else follows from the two limits built into that sentence. The inspection is not technically exhaustive — both national standards say so in those words — and it covers only what is readily accessible, which the standards define narrowly and which the condition of the house on the day determines. The inspector does not take things apart and does not move your belongings. What that leaves out is not a gap in the report; it is required to appear in the report, and in several states it is required by regulation.

What “readily accessible” means, and why it is narrower than you think

Three jurisdictions define the term, and the differences are worth knowing because they decide what you get.

That Massachusetts clause is materially narrower than the others and is almost never mentioned. It does not forbid an inspector from using a ladder; it means a component that can only be reached with one is not, by regulation, readily accessible — which bears directly on roofs, attic hatches and high exterior trim.

Across all three, the operative idea is the same. The inspector works with what the house presents on the day. Boxes in front of the panel, a bed under the attic hatch and a locked gate are not obstacles the inspector is expected to overcome.

The order the work usually goes in

No standard reviewed for this page prescribes an order. Inspectors are told what to examine and what to report, never in what sequence. The pattern below is convention rather than rule, but the logic behind it is worth understanding because it tells you when to show up and what you are watching.

Exterior and roof first. Light is best, the inspector is still dry, and roof access decides what equipment comes off the van. Roof covering, flashing, penetrations, gutters, grading and drainage, siding, trim, decks and balconies. No standard requires an inspector to walk any roof; InterNACHI’s standard says so explicitly and also relieves the inspector of removing snow, ice or debris to see one.

Structure, attic and crawlspace. Foundation, framing where visible, roof structure from readily accessible panels, doors or stairs, insulation type and approximate depth, ventilation. These are the dirtiest and most access-dependent parts of the job, and the ones most often truncated.

Mechanicals. Heating, cooling, ducts and vents, the water heater, the main water and fuel shut-offs, the electrical service, panel, over-current devices, grounding and bonding, and AFCI and GFCI devices. This is where normal operating controls get used — the system is switched on and watched.

Interior, room by room. Representative switches, receptacles and fixtures; windows and doors; walls, ceilings and floors; stairways and railings; fireplaces; kitchen and bathroom fixtures run and drained; garage and carport. Appliances, where the agreement includes them.

The verbal walk-through. Convention, not requirement, and the part most worth attending. See our guide on attending the inspection for when to arrive.

What has to be on and reachable

An inspection is a test of systems under power. If a system is off, it is not inspected — the standards do not require an inspector to energize anything that has been shut down, and in most cases prohibit it as a safety matter. This is the single largest preventable cause of a partial inspection.

On a vacant property — a foreclosure, an estate, a long-empty listing — assume nothing is on and arrange utilities in advance. It is the most common reason an inspection has to be repeated, and the second visit is a second fee.

When something is blocked, the report says so — and you carry the gap

This is the part of inspection day that matters most and gets written about least. An inspection stopped by an obstruction is a partial inspection. The standards do not let that disappear quietly; several states require it on paper.

Massachusetts requires every report to “Record the existence of obstructions and/or conditions that prevented the inspection,” and separately to “Indicate which systems and components that are present and designated for inspection in 266 CMR 6.04 which have not been inspected.” Illinois requires disclosure of systems not inspected, with reasons. Texas gives the inspector a dedicated checkbox — NI, used “when a component or system: is present but is not inspected” — alongside NP for components that are not present at all, and requires the inspector to explain the findings for each item. Kentucky requires reports to list exclusions “with specificity.”

North Carolina goes one further and polices it. The state board’s published list of the five most common report compliance failures includes, verbatim: “The home inspection report did not state the reasons systems and components designated for inspection by the Standards of Practice were not fully inspected.” A regulator put failure-to-disclose-an-exclusion on a top-five list, which tells you how often it happens.

Now the consequence, which nobody says plainly: the gap is yours. The inspector has met their obligation by disclosing it. The seller has no duty to arrange a second visit. If the attic was not entered because the hatch was blocked and you close anyway, you bought the attic unseen, and the report is the document proving you were told. Reading the exclusions is therefore not optional housekeeping — it is the only point at which that risk is yours to refuse.

When an exclusion appears, you have three options and they are all time-sensitive: arrange access and a re-inspection, bring in the specialist the exclusion points to, or accept it knowingly. Doing none of the three is the fourth option, and it is the one most buyers take by default.

Weather, and why two states make the inspector write it down

Massachusetts requires reports to “Record the weather conditions at the time of the inspection.” Illinois requires weather conditions as report content too. No other state rulebook reviewed does.

The reason is that weather silently changes what an inspection can establish. Snow or ice on a roof means the covering was not seen, and the InterNACHI standard expressly does not require an inspector to remove snow, ice or debris. Heavy rain the night before means a basement that is dry today proves little, and a basement that is wet today proves less than it looks. Cold weather means a cooling system cannot be run without risking damage to the compressor, so the air conditioner goes untested. Dry weather means nothing was observed about drainage under load.

Recording the weather turns all of that from an unstated assumption into a fact on the page. It is also the detail that makes a report readable months later — a dry crawlspace noted during a drought is a different piece of evidence from a dry crawlspace noted after three days of rain, and without the weather line you cannot tell which one you are holding.

If you are not in Massachusetts or Illinois, ask for it anyway, particularly if the inspection falls in the first cold snap or after a storm.

What does not happen during the inspection

Several things a buyer reasonably expects are outside the scope by design, and the inspector is not permitted to supply them. The inspector does not determine code compliance, does not perform engineering or architectural analysis, does not report on concealed or latent conditions, and in most jurisdictions does not estimate how much life a component has left. Environmental hazards — radon, asbestos, lead paint, mold, water quality, pests — are excluded almost everywhere and bought as separate services.

None of that is the inspector being unhelpful. It is the boundary the standards draw, and it is the subject of our guide to what an inspector may not determine, including the live federal form that contradicts both national standards on remaining useful life.

What to do with this

Before the day: confirm in writing that electricity, gas and water will be on, that pilot lights will be lit, and that the attic hatch, crawlspace access, electrical panel, furnace and water heater are clear. Ask who is supplying keys and codes for gates and outbuildings, and whether pets will be secured. For a vacant property, treat utilities as your problem until someone proves otherwise.

On the day: arrive for the later part, bring nobody, operate nothing, and ask the inspector directly what they could not reach. That question, asked while you are standing there, is worth more than any other you will ask.

Afterwards: read the exclusions before you read the defects. Then read how to read a home inspection report and when you get the report, because the clock on acting runs from delivery and not from the visit — and if you want to know how long the visit itself should take, our page on how long a home inspection takes explains why no authority has ever said.

Frequently Asked Questions