What Does a Home Inspection Include and Exclude?

A home inspection is a visual, non-invasive walkthrough of a house’s accessible structure and major systems, performed by a trained professional following protocols set by the American Society of Home Inspectors (ASHI) or the International Association of Certified Home Inspectors (InterNACHI). What a home inspection includes, in practice, is the roof and exterior, the foundation and framing, the plumbing and electrical systems, heating and cooling equipment, built-in appliances, ventilation, and life-safety devices. It typically runs two to three hours for an average-sized home, costs $300 to $500, and ends with a written report organized by system. What it does not include is just as important: environmental hazards, pests, water quality, underground systems, and pools all fall outside the standard scope.

Roof and Exterior

The inspector starts outside. Roofing materials — asphalt shingles, metal, tile — get checked for wear, curling, and missing pieces. Flashings around chimneys, skylights, and other roof penetrations get particular attention, because failed flashing is one of the most common ways water gets into a house. Gutters, downspouts, and overall drainage are reviewed to confirm water moves away from the structure instead of pooling against it.¹

At ground level, the review covers wall coverings, trim, exterior doors, eaves, soffits, and fascia, looking for rot, pest damage, and deterioration. Decks, balconies, porches, and exterior stairways are checked for structural integrity at their surfaces, connections, and railings.¹

Grading around the foundation is a major focus. Soil should slope away from the building. Driveways, walkways, and patios are checked for settling or cracking that could redirect water toward the home.

Structure and Foundation

Inside, the inspector looks for signs of structural movement: diagonal cracks running from the corners of door and window frames, noticeably sloping floors, doors that won’t latch. Stairs and railings are tested for stability and checked against standard safety dimensions.¹

A representative number of windows and doors are opened, closed, and locked. That’s enough to spot patterns like failed seals, broken hardware, or frames warped by settling. The attic and crawlspace are where the primary framing is exposed, so inspectors evaluate joists, rafters, and beams there for cracks, sagging, or water damage, and note insulation levels and ventilation. Stair-step cracking in block or brick foundation walls, bowing walls, and visible slab heaving are the red flags that most reliably signal foundation distress.¹

Plumbing

The plumbing portion covers the interior water supply and distribution system that’s visible during the visit. Inspectors identify piping materials — copper, PEX, galvanized steel, or CPVC — and note corrosion, active leaks, or amateur repairs. A representative number of fixtures and faucets are run to check water pressure and confirm hot water reaches the tap in a reasonable time.¹

Drains are tested by running water and watching how it clears. Slow drainage across multiple fixtures often signals a problem in the main waste line, not a local clog. Sump pumps and sewage ejectors, where present, are operated to confirm they work.

Water heating equipment gets its own look. The inspector notes the type (tank or tankless), fuel source, and approximate age. A standard tank water heater lasts roughly 10 to 15 years; tankless units can run 20 years or more. The temperature and pressure relief valve and its discharge pipe are checked, because that’s the water heater’s critical safety device: the discharge pipe must run downhill without any shutoff valves or obstructions and terminate where a release of scalding water won’t hurt anyone. Gas-fired units are checked for proper venting, and the inspector notes where the main water and fuel shut-offs are.¹

Electrical

The electrical review starts where power enters the building: the service drop, entrance conductors, and exterior service equipment. The inspector confirms the home can be safely de-energized at the main disconnect and notes the amperage rating, which tells you whether the service is adequate for the home. Older homes with 60-amp service are likely to need an upgrade.

Inside, the main service panel and any subpanels are opened to examine breakers, wiring, and bus bars. Two problems come up constantly. The first is double-tapped breakers, where two wires are crammed into a terminal designed for one, creating a loose connection that can overheat and arc. The second is signs of overheating: scorched wires, melted insulation, discolored breakers. The grounding system is verified at the same time.¹

A representative number of switches and outlets are tested throughout the home to confirm they’re powered and correctly wired. Ground fault circuit interrupter (GFCI) protection is checked in locations near water — bathrooms, kitchens, garages, outdoor receptacles, crawlspaces, and unfinished basements. Arc fault circuit interrupters (AFCIs), which protect against electrical fires caused by damaged wiring, are evaluated where present.¹ Certain panel brands get flagged on sight. Federal Pacific Electric panels with Stab-Lok breakers and Zinsco panels are both known for breakers that fail to trip reliably, and most inspectors recommend full replacement when they see either one.²

Heating and Cooling

Heating and cooling equipment is tested using the home’s normal controls, meaning the thermostat. Furnaces, boilers, and heat pumps are run to verify they respond, produce heat, and don’t show obvious safety problems like cracked heat exchangers or blocked flue vents. Central air conditioning is checked the same way, but inspectors won’t run it when outdoor temperatures are too low, because doing so can damage the compressor.¹

Ductwork, registers, baseboards, and radiators are inspected for visible damage, disconnections, and significant blockages. The inspector checks for air filters and notes the general condition of the air handler. This part of the review is less about precise temperature measurements and more about whether conditioned air actually reaches the rooms it’s supposed to reach.

Appliances, Ventilation, and Life-Safety Devices

The inspection covers permanently installed kitchen appliances: the range, oven, built-in microwave, and dishwasher. Each is activated to confirm basic operation. Portable or freestanding appliances, like a countertop microwave or a standalone refrigerator, aren’t part of the standard scope because they aren’t considered part of the real property.

Bathroom exhaust fans and kitchen range hoods are tested for operation. These matter more than most buyers realize. A bathroom fan that doesn’t actually vent to the exterior dumps moisture into the attic, which over time causes mold and wood rot.

Under the ASHI standard, inspectors also describe the presence or absence of smoke alarms and carbon monoxide alarms throughout the home.¹ Carbon monoxide detectors should be installed outside each sleeping area and on every level of a home with fuel-burning appliances.³ Missing or non-functional detectors are easy fixes, but they appear in the report because they’re life-safety items.

What a Home Inspection Does Not Cover

This is where most misunderstandings happen. A standard home inspection is a visual review of accessible components. The inspector doesn’t move furniture, cut into walls, or dig up the yard. Several categories of concern fall entirely outside the scope:

Environmental hazards. Radon, lead paint, asbestos, and mold testing all require separate specialized inspections. The ASHI standard explicitly excludes environmental hazards, including radioactive substances, toxins, and contaminants in building materials, soil, water, and air.
Wood-destroying organisms. Termite and pest inspections are performed by licensed pest control operators, not home inspectors. Many lenders require a separate termite report anyway.
Water quality. The inspector checks that water flows and drains, not whether it’s safe to drink. Well water testing is a separate process.
Underground systems. Septic tanks, underground storage tanks, sewer lateral lines, and buried fuel tanks are excluded. They can’t be seen, so they aren’t part of a visual inspection.
Swimming pools and spas. These require specialized inspectors familiar with pump systems, structural integrity, and barrier code compliance.

The ASHI Standard of Practice spells out these exclusions clearly.¹

Add-On Inspections Worth Paying For

Depending on the home’s age, location, and construction, several add-ons are worth the money. Radon testing is at the top of the list for any home with ground-level or below-grade living space. The EPA recommends remediation at indoor radon levels of 4 pCi/L or higher, and suggests considering action between 2 and 4 pCi/L, because no exposure level is considered safe.⁴ A radon test typically runs $150 to $250 when bundled with the home inspection.

A sewer scope uses a camera to examine the lateral line connecting the house to the public sewer. Root intrusion, corroded pipe, collapsed sections, and bellied lines are common problems invisible from inside the house, and repairs can run into five figures. Some municipalities now require a sewer scope before issuing a certificate of occupancy at sale. If the home is older than about 30 years, this one pays for itself.

Reading the Report

The inspection report is organized by system: roof, exterior, structure, plumbing, electrical, HVAC, interior, and appliances. Within each section, findings are categorized by severity. Categories vary by inspector, but most reports distinguish safety hazards that need immediate attention, major defects that are expensive to repair, and minor maintenance items. A handful of cosmetic notes and deferred maintenance in a report is normal. A cluster of safety or structural findings in one area is a different conversation.

If you’re buying, the report feeds directly into your contingency period, typically 7 to 10 days from the date of the purchase agreement, though some states allow more. During that window you review the findings and decide how to respond — usually by asking the seller to make repairs, requesting a credit toward closing costs, negotiating a price reduction, or walking away if the inspection changes the value proposition entirely.

Picking an Inspector and Showing Up

Show up for the inspection if you can. Walking through with the inspector gives you context no written report delivers on its own. You can ask questions in real time, see the severity of issues firsthand, and pick up maintenance tips specific to this house. The report makes far more sense when you’ve already watched the inspector point to the problem.

Look for ASHI or InterNACHI membership, which means the inspector has committed to a published standard of practice and a code of ethics. That code has teeth. An ASHI-certified inspector cannot repair, replace, or upgrade any system covered by the standard of practice for one year after performing the inspection.⁵ That rule exists so inspectors can’t drum up their own repair work by exaggerating defects. Many states have adopted similar prohibitions into their licensing laws.

1
American Society of Home Inspectors, Inc. Standard of Practice
2
U.S. Consumer Product Safety Commission. Commission Closes Investigation of FPE Circuit Breakers and Provides Safety Information for Consumers
3
National Fire Protection Association. Carbon Monoxide Safety
4
US EPA. What is EPA’s Action Level for Radon and What Does it Mean
5
American Society of Home Inspectors, Inc. Code of Ethics