What Does a Home Inspector Look For? A System-by-System Walkthrough
Home inspectors operate against a written Standard of Practice (most commonly the ASHI Standard or the InterNACHI equivalent), which defines what is and is not included in a standard residential inspection. Buyers who understand the scope walk into the inspection knowing what to expect; buyers who do not are sometimes surprised to find their inspector skipping things they assumed were covered. This guide walks through what is in scope, system by system.
InspectandTest is an independent editorial team. We are not licensed home inspectors. This guide synthesizes the ASHI Standard of Practice and InterNACHI’s Residential Standards of Practice. Specific scope items vary by inspector contract; read your inspection agreement.
Structural components
The inspector evaluates visible structural components: foundation, framing, floors, walls, ceilings, and roof structure where accessible (typically from the attic). They look for evidence of movement (cracking, settlement), water damage, pest damage, and deviations from typical construction practice. They do not destructively probe; they do not make engineering calculations; they do not certify structural adequacy. For any significant concern, they recommend further evaluation by a structural engineer.
Exterior
Cladding (siding, brick, stucco), trim, eaves, soffits, fascia, exterior windows and doors, walkways, driveways, and accessible portions of the property. The inspector checks for damage, deterioration, drainage issues, and visible defects. They evaluate grading and drainage as it affects the foundation. They do not evaluate landscape, fences, swimming pools (unless contracted as add-on), retaining walls, or detached structures unless specifically included.
Roofing
Roof covering, flashings, drainage components (gutters, downspouts), penetrations (vents, chimneys, skylights), and visible roof structure. Inspection method varies: from ground level, from ladder at eave, by walking the roof, or by drone. The inspector estimates remaining useful life based on visible condition; they do not perform tear-off evaluation, structural roof analysis, or moisture testing of roof materials.
Plumbing
Visible portions of the supply system, drain-waste-vent system, fixtures, water heater, and visible piping. They identify the supply pipe material (copper, PEX, galvanized, polybutylene). They run water at every accessible fixture and observe for leaks, drainage issues, and abnormal pressure. They check water heater age, capacity, T&P valve, and visible condition. They do not perform pressure tests, sewer scope (separate service), septic system evaluation, well water testing, or evaluation of components inside walls.
Electrical
Service entrance, electrical panel, branch circuits, devices and switches in representative quantities, and major fixed equipment. They check panel condition, breaker sizing, GFCI and AFCI protection where required, outlet wiring polarity and grounding, and obvious safety concerns. They do not load-test circuits, do not pull panel covers for detailed busbar inspection (some inspectors do; many do not, citing safety), do not evaluate low-voltage systems, and do not check for code compliance against current code.
HVAC
Heating and cooling systems, distribution components, and controls. The inspector confirms the system runs and produces expected outputs (warm air at registers in heating mode, cool air in cooling mode where outdoor temperature permits). They check accessible filter, condensate drain, refrigerant lines, and visible ducts. They estimate equipment age from nameplate. They do not perform combustion analysis, do not measure airflow at registers, do not evaluate refrigerant charge, do not perform load calculations, and do not internally inspect heat exchangers. For older or suspect systems, they recommend HVAC technician follow-up.
Interior
Walls, ceilings, floors, doors, windows, and stairs. The inspector checks for obvious damage, water staining, evidence of past repairs, and operational issues with windows and doors. They check for required smoke and carbon monoxide alarms in standard locations. They do not lift carpet or flooring for sub-floor evaluation, do not move furniture or stored items, do not test interior air quality, and do not evaluate cosmetic finishes.
Insulation and ventilation
Visible attic insulation type and depth, attic ventilation (soffit and ridge vents), and the operation of exhaust fans (bathroom, kitchen). They flag missing insulation, blocked ventilation, and exhaust fans terminating in attic instead of through the roof. They do not measure R-values precisely, do not perform energy audits, and do not evaluate vapor barriers in concealed locations.
Built-in appliances
Built-in cooking appliances, garbage disposal, dishwasher, built-in microwave. The inspector confirms basic operation; they do not test full cooking cycles, do not evaluate efficiency, and do not test components beyond basic on-off function. Free-standing appliances vary by contract.
What is typically excluded from the standard scope
- Specialty hazard testing: radon, mold, asbestos, lead, formaldehyde, VOCs
- Sewer line interior condition (sewer scope as separate service)
- Septic systems (specialty inspection)
- Well water quality (lab testing)
- Swimming pool and spa equipment (specialty inspection)
- Chimney internals (CSIA-certified sweep)
- Underground tanks (oil tank specialty)
- Solar PV systems (solar specialty)
- Wood-destroying organisms (WDO inspection, often required for VA loans)
- Code compliance certification
- Future failure prediction or warranty
- Cosmetic conditions and aesthetic items
The right buyer mental model
The standard home inspection is the screening layer of a layered due diligence package. It catches the most obvious significant defects, identifies the components requiring further specialty evaluation, and produces a documented record of the home’s condition on the day of inspection. It is not the comprehensive layer. For any property with specific risk profiles (age, location, prior history), layer in the appropriate specialty inspections.
Our companion guide on what home inspectors typically miss walks through the categories of defects the standard scope does not catch and the specialty inspection layer that closes the gap.