Understanding Home Inspections: What They Cover and What They Miss

A general home inspection is a visual, non-invasive survey of a house performed by a generalist. It is genuinely valuable, and it is also limited by design: the inspector does not open walls, dismantle equipment, or run specialized tests on the electrical, plumbing, or heating systems. Knowing where the inspection stops is how buyers avoid expensive surprises after closing.

What does a general home inspection cover?

A standard inspection follows a defined scope: the inspector examines readily visible and accessible parts of the home and reports on their apparent condition on that day. That typically includes the roof surface, structure, siding, drainage, attic and crawlspace where accessible, plumbing fixtures, water heater, heating equipment, and the electrical panel and a sampling of outlets.

Done well, this catches a great deal: active leaks, obvious amateur wiring, a furnace at the end of its life, missing seismic straps on a water heater, ungrounded outlets, moisture in a crawlspace. In a region full of pre-1980 houses with decades of owner projects layered inside them, a good generalist earns their fee many times over.

What does an inspection NOT cover for electrical, plumbing, and HVAC?

Here are the scope limits in plain words. None of this is a criticism of inspectors. It is the definition of the job.

• Electrical: the inspector removes the panel cover if it is safe to do so, and tests a sample of outlets. They do not trace circuits, load-test the service, verify that past work was permitted, or inspect wiring inside walls. Aluminum branch wiring and buried junction boxes routinely escape a visual survey.
• Plumbing: the inspector runs fixtures and looks for visible leaks. They do not camera the sewer line, pressure-test supply lines, or determine the remaining life of galvanized pipe hidden in walls. A drain can flow fine for twenty minutes and still belong to a root-invaded sewer.
• HVAC: the inspector operates the system using normal controls and observes response. They do not measure refrigerant charge or static pressure, and heat exchangers, the part of a furnace whose cracks matter most, are mostly hidden from visual inspection without disassembly.

Inspection reports say this themselves, in the standards-of-practice language most buyers skip. The phrase to respect is some version of: this was a visual inspection of accessible components only.

Which findings deserve a specialist evaluation?

When a report says a licensed electrician, plumber, or HVAC contractor should evaluate further, that sentence is not boilerplate. It is the inspector telling you they saw the edge of something their scope cannot resolve. Findings that reliably justify the follow-up:

• Legacy panel brands such as Federal Pacific or Zinsco, or any panel with double-tapped breakers and scorch marks. A dedicated electrical inspection can determine whether the panel is serviceable or a replacement candidate.
• Knob-and-tube or aluminum wiring visible anywhere, because where you see a little, there is usually more.
• A water heater near the end of its typical life, or one missing code items like an expansion tank or seismic straps.
• Furnaces and heat pumps past the midpoint of their expected life, especially with no maintenance records.
• Any sign of past unpermitted work: mismatched materials, amateur junctions, missing inspection stickers.

The cost logic is simple. Specialist evaluations cost little compared to what they can save you in negotiation, and a written finding from a licensed trade professional carries weight a general report cannot.

Why is the sewer scope the classic example?

Because it is the highest-stakes system a general inspection cannot see. The side sewer, the buried pipe running from the house to the main, belongs to the homeowner in Seattle, and much of the region's housing stock still drains through original concrete or clay lines that roots love. A failed sewer is among the most expensive single repairs a house can need, and it can hide behind drains that flow normally on inspection day.

A sewer scope puts a camera through the line and shows you its actual condition: root intrusion, offsets, bellies, breaks. For older homes it is widely considered essential due diligence, and it is cheap insurance against a repair that can cost more than a roof. If the scope finds trouble, our sewer line page explains the repair options, which range from spot repairs to trenchless lining.

Should sellers get a pre-listing inspection?

Often, yes. A pre-listing inspection lets you find and fix issues on your own schedule instead of discovering them mid-negotiation, when every finding costs more in concessions than the repair itself. It also signals good faith to buyers in a market where waived inspections have burned people.

The honest counterpoint: once you know about a material defect, you generally must disclose it. A pre-listing inspection is a commitment to deal with what it finds, not a marketing document. Sellers who want the benefit without the follow-through should skip it.

How do trade evaluations fit into a purchase?

Use the general inspection as the map and specialist evaluations as the deep dives on whatever the map flags. Timing matters: inspection contingency windows are short, so book trade evaluations the same week. A licensed multi-trade company can often evaluate the panel, plumbing, and heating system in a single visit; Eco does this regularly for buyers working against a contingency deadline, and a full system inspection covers the mechanical side in one appointment.

Before you tour houses, it also helps to know what to look for yourself. Our homebuyer inspection checklist covers the visible warning signs in panels, pipes, and heating equipment that you can spot before you ever write an offer.

Common questions

Is the inspector supposed to catch everything?

No, and the contract you signed says so. The inspector reports the apparent condition of visible, accessible components on one day. Hidden defects, intermittent problems, and anything requiring disassembly or specialized tools are outside the scope. Treat the report as a well-informed starting point, not a guarantee.

Can I use inspection findings to negotiate?

Yes, and specialist findings negotiate better than general ones. A report line that says the panel should be evaluated is a question mark. A licensed electrician's written finding that the panel is a known-hazard brand with a documented failure mode is a number you can put in an addendum.

Do new construction homes need an inspection?

Yes. Municipal inspections during construction verify code compliance at specific stages; they do not verify workmanship quality across the whole house. New homes routinely turn up flashing errors, plumbing left unconnected, and HVAC commissioning that never happened. Inspect before the warranty period expires, too.

What to do next

If you are buying, book the general inspection first, then line up specialist evaluations for anything it flags, with the sewer scope near the top of the list for any older home. If you want the electrical, plumbing, and heating side handled in one visit, Eco can schedule a system inspection inside your contingency window. Book online or call (206) 970-1031, 6 AM to 6 PM every day.