A limited, visual examination of one day
A home inspection is a limited, non-invasive, visual examination of a residential property's readily accessible, installed systems and components, performed for a fee and reported in writing. It is a snapshot of observed condition on one day — not a warranty, not a code inspection, not an engineering evaluation and not a valuation. The two governing standards, the ASHI Standard of Practice and the InterNACHI Standards of Practice, say so explicitly rather than by implication.
InterNACHI defines an inspection as "a non-invasive, visual examination of the accessible areas of a residential property ... designed to identify defects within specific systems and components defined by these Standards that are both observed and deemed material by the inspector," based "on the observations made on the date of the inspection, and not a prediction of future conditions."
The threshold term is material defect — an issue "that may have a significant, adverse impact on the value of the property, or that poses an unreasonable risk to people." Note what that does not say. Not anything short of current code. Not anything the buyer would prefer were different. Materiality is the inspector's own judgment, written into the standard, which is why two competent inspectors produce different reports on the same house without either being wrong. ASHI sets the bar from the other side: the report describes whatever was judged "not functioning properly, significantly deficient, unsafe, or nearing the end of service life." Significantly deficient is the trigger, not imperfect.
The exclusions are not fine print. They are the standard
Consumer material treats the exclusion list as a disclaimer bolted on at the end. It is the opposite: the exclusions define the shape of the product. Each system section of ASHI's standard — structure, roofing, plumbing, electrical, heating, and the rest — has the same two-part shape: an X.1 The inspector shall block, then an X.2 The inspector is NOT required to block.
Section 13, General Limitations and Exclusions, then applies across the whole document. An inspection is "not technically exhaustive" and need not identify "concealed conditions, latent defects, consequential damages" or cosmetic imperfections. The general exclusions are then sorted by verb. The inspector is not required to determine (life expectancy, adequacy, cause, or the costs of correction), to offer (engineering, architectural or contracting services, or warranties), to operate (shut-down systems, shut-off valves, safety controls), to enter (dangerous or inaccessible crawlspaces and attics), or to inspect (underground storage tanks, detached structures other than garages, and every similar component occurrence — a report is a sample, not a census). A final bucket disposes of code compliance, market value, advisability of purchase, molds and environmental hazards.
InterNACHI arrives by another route: ten flat limitations, then three parallel lists of what the inspector need not determine, need not operate, and need not do at all. Its limitations are blunter — an inspection does not determine suitability, market value, insurability, advisability of purchase, or life expectancy.
The single most useful line for a buyer. Neither standard requires the inspector to determine compliance with codes or regulations. A home inspection is not a code inspection and a home inspector is not a code official. "He never told me it wasn't to code" is the trade's most common complaint, and he was never required to.
Who the inspector works for, and what he may not conclude
The inspector is engaged by, paid by and reports to whoever signs the inspection agreement — in a purchase, normally the buyer. That agreement, the standard he practises under, and any state licensing law are the whole of what he owes. He is not the lender's agent and not a neutral arbiter.
What he may produce is narrower still. He reports conditions. He does not certify the house, guarantee anything, price repairs, determine code compliance, opine on the adequacy of a structural system, or advise whether to buy. Each is a written exclusion, not an evasion. So "recommend evaluation by a licensed structural engineer" is performing the standard — ASHI requires recommendations to address deficiencies or items needing further evaluation — while an inspector who confidently quotes repair costs has stepped outside it.
The obligation buyers overlook is the mirror image of the defect list: ASHI requires the inspector to report any system that was not inspected, and why. \Attic not entered — insufficient headroom at access hatch" discharges that duty completely while telling the buyer the roof structure, attic wiring, insulation and ventilation went unexamined. The thresholds are numeric: a crawlspace under 24 inches of clearance, or an access opening smaller than 16 by 24 inches, need not be entered.
There is no national home inspector license
Licensing is a state matter and it is not universal. InterNACHI's licensing hub puts it plainly: some states regulate home inspectors by issuing licenses and some do not. Roughly two-thirds license or register inspectors; a substantial minority have no state-level requirement at all. Published counts disagree with each other and with primary law — Massachusetts appears on some no-license lists yet has a Board of Registration of Home Inspectors and codifies its own exclusions by regulation — so a hard number is not worth relying on.
Where there is no licensing the consequence is blunt: no credential to check, no board to complain to, and nothing stopping anyone from printing a business card that says home inspector. The remaining filters are contractual: certification in ASHI or InterNACHI, which binds an inspector to a published standard and a code of ethics by agreement rather than by statute; errors-and-omissions insurance; and a full sample report, the most revealing of the three. Where a state does license, the licence is a floor, not a description of how this inspector works.
Where the general inspection ends and the specialists begin
The general inspection is a triage instrument, built to find the conditions that warrant a specialist. Both standards say so by exclusion: the things buyers fear most are the things expressly carved out. The inspector's job is not to perform these but to flag the trigger.
| Specialty inspection | When it is warranted |
|---|---|
| Sewer scope | Older houses, mature trees over the lateral, clay or Orangeburg pipe, past backups |
| Radon test | EPA and the Surgeon General recommend that all houses be tested |
| Mold and air quality | Visible growth, musty odor, elevated moisture, prior flooding |
| Wood-destroying insect | Lender-required on most VA and many FHA loans in termite areas; wood-to-soil contact |
| Structural or geotechnical engineer | Foundation movement, stair-step cracking, sloping floors, expansive clay or fill |
| Chimney evaluation | Any solid-fuel appliance, a known chimney fire, a change of fuel |
| Well yield and potability | Every private-well property; flow and water quality are two separate tests |
| Septic evaluation | Every septic property; EPA's baseline is inspection at least every three years |
| Asbestos survey | Pre-1980 duct wrap, pipe insulation, 9x9 tile or asbestos siding; before any renovation |
| Lead-based paint | Pre-1978 housing; federal law gives a ten-day assessment opportunity by default |
| Pool and spa | Any pool or spa; equipment bonding and grounding is a life-safety item |
| Oil tank sweep | Older houses that ever had oil heat; a buried tank is a liability running with the land |
The point buyers miss is scheduling, not cost. Each specialty runs on its own clock, and an engineer or a septic contractor may not fit inside a seven-day window. That calendar reality, not the fee, is why the inspections that mattered get skipped.
Reading the report, and why the summary is not the report
Neither standard dictates what a reporting template calls things. They define what must be reported; the labels belong to the inspector's software. Mapped back onto the standards, four tiers separate out, carrying very different weight.
- Safety hazard. Maps to "unsafe" in ASHI's reporting duty and to InterNACHI's "unreasonable risk to people." These resurface later as lender and insurer conditions.
- Material defect. Significant adverse impact on value, or unreasonable risk — the only class with defined standing in either standard.
- Maintenance item. No standing at all: a condition not judged significantly deficient that day. A task list, not a negotiating position, and if it worsens it worsens on the buyer's side of closing.
- Note or observation. Descriptive, not diagnostic. Also where "nearing the end of service life" sits: a reporting trigger, not a forecast, since both standards exclude determining life expectancy.
The failure mode is reading only the summary. Software builds one by pulling flagged items out of the body, for negotiation rather than comprehension. Three things rarely survive the extraction: the photographs and qualifying sentences explaining why a finding matters, the observations that establish what the house is, and the not-inspected list. A summary tells a buyer what to ask the seller for; only the full report tells a buyer what they are buying, and the absence of a finding is never evidence a component is sound. Both standards are published by ASHI and InterNACHI.
Nothing passes and nothing fails
There is no score, no threshold and no certificate. A report obligates nobody to do anything: not the seller to repair, not the buyer to proceed, not the lender to lend. Its only force is whatever force the purchase contract lends it through the inspection contingency, and the only deadline that matters is the contingency's.
What people call failing an inspection is three different events. A finding severe enough that the buyer walks or demands a concession — a live roof leak, structural movement, a failed septic system. A lender condition, which arrives through the appraisal rather than the inspection, since an appraiser can make a report subject to repairs. And an insurer declining to bind coverage over an obsolete panel, aluminum branch wiring, knob-and-tube, polybutylene piping or roof age. An uninsurable house is an unfinanceable house, and that one surfaces late, when the carrier reads the report.
What follows findings is a negotiation in three non-equivalent currencies: a completed repair, a closing-cost credit, or a price reduction. They are not interchangeable. Only a completed repair satisfies a lender's repair condition; a credit is capped by investor rules and cannot be taken as cash back; a price cut avoids the caps but hands the buyer no money at the table.
Where each thread is picked up
Six guides sit beneath this page, each carrying one thread further than an orientation can. What the standards affirmatively exclude — the general lists, the per-system carve-outs, the specialty inspections a buyer orders separately — has its own guide, as do pricing and duration. The inspection-versus-appraisal distinction is treated separately because it is the substitution buyers make most often and pay for most dearly; HUD's consumer form states outright that appraisals are not home inspections. The contract mechanics are their own subject, as are the findings that end transactions and the checklist for the day itself.
They converge on one idea. Information has a shelf life set by the contract, not by the physics of the defect. Physical condition is actionable during the inspection period and essentially nowhere afterward, and a buyer who is right but late is in the same position as a buyer who is wrong.
Frequently Asked Questions
What is a home inspection?
It is a limited, non-invasive, visual examination of a residential property's readily accessible, installed systems and components, performed for a fee and delivered as a written report. Under the InterNACHI standards it is designed to identify defects that are both observed and deemed material by the inspector, based on the observations made on the date of the inspection and not as a prediction of future conditions. Under the ASHI standard the inspector examines readily accessible, visually observable, installed systems and reports what is not functioning properly, significantly deficient, unsafe, or nearing the end of service life. Every one of those qualifiers narrows the product, and together they narrow it considerably more than most buyers expect.
What does a home inspection cover?
Both standards define much the same required systems list: structure, exterior, roofing, plumbing, electrical, heating, air conditioning, interiors, insulation and ventilation, and fireplaces and fuel-burning appliances. Within each, the inspector examines what is readily accessible and visually observable, describes what he found, and operates certain components using their normal controls. What is not covered is defined just as precisely, section by section, and those per-system exclusion lists are where most post-closing surprise originates. Both standards also apply only to buildings with four or fewer dwelling units and their attached garages and carports.
Does a home inspector check whether the house meets code?
No. Neither standard requires the inspector to determine compliance with codes or regulations, and both list it explicitly among the exclusions. A home inspector is not a code official, has no enforcement authority, and usually has no access to the permit record. He may note that work appears to have been added, or that a condition is unsafe in his judgment, but a report that does not mention a code issue is not evidence that none exists. Permit history is a separate line of due diligence a buyer pursues through the municipality.
Can a house fail a home inspection?
No. There is no pass, no fail, no score and no certificate, and neither standard permits the inspector to advise on the advisability or inadvisability of a purchase. The report identifies observed material defects and stops there; it obligates the seller to nothing and the buyer to nothing. What people call a failed inspection is one of three separate events: a buyer choosing to terminate or renegotiate, a lender conditioning the loan through the appraisal, or an insurer declining to write a policy. Only the first has anything to do with the inspection report itself.
Do home inspectors have to be licensed?
It depends entirely on the state. Licensing is a state matter, roughly two-thirds of states license or register home inspectors, and a substantial minority do not regulate the occupation at all. In a non-licensing state there is no credential to verify and no state board to complain to, and nothing prevents anyone from using the title. The practical substitutes are certification and membership in ASHI or InterNACHI, which bind an inspector to a published standard of practice and a code of ethics by contract rather than by statute, evidence of errors-and-omissions insurance, and a complete sample report read before hiring rather than after.
Who does the home inspector work for?
The party who signs the inspection agreement, which in a purchase is normally the buyer. The inspector is not engaged by the lender, is not a neutral third party between buyer and seller, and owes his duties under that agreement, the standard he practises under, and any applicable state licensing law. This matters when a report gets forwarded: a seller who receives the full report may acquire a disclosure obligation toward future buyers, and adding parties to the inspection creates confusion about who the report was written for.
Is a home inspection required to buy a house?
No lender requires one, and there is no statutory home inspection period in any state. The right to inspect and the right to act on what an inspection finds are creatures of the purchase contract alone, which is why the same buyer gets structurally different exits in different states. HUD's consumer form makes the corollary explicit for FHA borrowers: a home inspection will only occur if the buyer arranges for one, and FHA does not perform home inspections. The appraisal a lender does require is a value opinion produced for the lender, not a condition assessment produced for the buyer.
What can I do if the inspector missed something?
Start by reading what the report actually said, because a great many alleged misses are disclosed exclusions. Both standards relieve the inspector of any obligation to offer warranties or guarantees, to identify concealed or latent defects, to enter areas that are unsafe or inaccessible, or to examine every similar component occurrence, and both require him to state what he did not inspect and why. Inspection agreements themselves commonly contain limitation-of-liability and dispute-resolution terms, which vary widely and are worth reading before signing rather than afterward. Where an inspector is state-licensed there is generally a board that accepts complaints; where he is not, the recourse is whatever the private agreement provides.