Home Electrical Inspection Before Buying

The electrical system is one of the more expensive things to fix in a house and one of the least thoroughly covered by a standard inspection. Knowing the gap is what lets you close it before the contingency period ends.

What to flag before closing

The three rows worth real money — a defective panel brand, live knob and tube, and an undersized service against your plans — are all worth pricing before the inspection contingency expires, not after.

What does a general home inspection cover?

A competent general inspector will typically:

• Open the panel cover and look inside
• Note the service size and panel type
• Test a sample of receptacles with a plug-in tester
• Check GFCI devices where present
• Note visible defects — open junction boxes, exposed splices, obvious damage
• Identify visible wiring types in accessible areas
• Check smoke and CO alarms
• Flag anything that looks wrong for further evaluation

That's genuinely useful, and it catches a lot.

What it typically doesn't cover

The gaps matter more than the coverage:

No load calculation. Nobody determines whether the service supports what you intend to do — which matters enormously if you plan a heat pump, EV charging, or an induction range. See electrical capacity for an all-electric home.

No concealed wiring assessment. Only what's visible. The condition of insulation inside walls is unknown.

No circuit tracing. Which receptacles are on which circuit, and whether circuits are overloaded, generally isn't mapped.

Plug-in testers can't detect a bootleg ground. A jumper between neutral and ground reads as a correctly grounded outlet. See what is a bootleg ground.

No insurability determination. Whether an insurer will write a policy on this wiring is not an inspection finding.

Limited access. Finished basements, full attics and furnished rooms limit what can be seen.

No remediation pricing. "Recommend evaluation by a licensed electrician" is a finding, not a number.

When to hire an electrician separately

Worth the extra cost when:

• The general inspector flagged anything electrical
• The house has knob and tube — see knob and tube wiring
• The house has aluminum branch wiring — see aluminum branch circuit wiring
• The panel is an obsolete or known-problem type — see signs your electrical panel is failing
• You plan to electrify or add EV charging
• The house is older and you want the capacity question answered
• There's evidence of DIY or unpermitted work

An electrician's assessment costs a fraction of what a surprise rewiring costs, and it produces something an inspection report doesn't: a price.

What to ask them to determine

Be specific about what you need:

1. What wiring types are present, and in what condition?
2. Is there aluminum branch wiring? If so, what remediation is accepted locally and what does it cost?
3. What's the service size, and does a load calculation support my plans?
4. What's the panel type and condition? Are breakers available for it?
5. Are circuits properly grounded? Any bootleg grounds?
6. Is GFCI and AFCI protection present where current code would require it?
7. Is there evidence of unpermitted work?
8. What would it cost to add the circuits I want — EV charger, heat pump, induction range?
9. What needs doing now versus what can wait?

That last question separates safety issues from wish-list items, which is what you need for negotiation.

The expensive findings

Roughly in order of cost impact:

Aluminum branch-circuit wiring. Remediation means either full copper rewiring or an approved connector method applied at every connection. Both are substantial. Insurers frequently require it.

Extensive knob and tube, particularly if buried in attic insulation — a genuine fire risk and often an insurability problem.

An obsolete or known-problem panel. Replacement, and sometimes a service upgrade with utility coordination.

An inadequate service for your plans. A service upgrade is one of the more expensive electrical projects.

Deteriorated insulation on existing conductors, which points toward rewiring. See cloth and rubber insulated wiring.

Extensive unpermitted work, which may need retroactive permitting — potentially opening finished walls.

Check insurability during diligence

This catches people, and it's avoidable.

Insurers vary considerably in what they'll write. Some refuse knob and tube or aluminum branch wiring outright; some surcharge; some require remediation within a set period.

Get insurance quotes with the wiring type disclosed before your contingency period ends. Discovering after closing that you can't get standard coverage is a much worse position than discovering it during diligence — and it may change what the house is worth to you.

Walking the house yourself

Before the professionals, a fifteen-minute look tells you a lot:

At the panel: the service rating on the main breaker, whether there are spare spaces, the panel brand, and whether the labeling is legible. See how to read your electrical panel.

In the basement and attic: wiring types. Ceramic knobs and separated conductors mean knob and tube. Check whether attic wiring is buried in insulation.

At receptacles: two-prong or three-prong? Any discoloration or scorching? Do plugs fit firmly?

In kitchens and bathrooms: GFCI protection present?

Everywhere: open junction boxes, exposed splices, extension cords in permanent use (a sign of too few receptacles), and visible DIY work.

Cable markings: look for AL or ALUMINUM printed on cable jackets at the panel.

Note what you find and hand it to the electrician — it focuses their time.

Negotiating

Once you have findings and a price:

• Separate safety issues from upgrades. A seller may fix a hazard; they're less likely to fund your EV charger.
• Get written quotes, not estimates, for anything material
• Consider a credit rather than seller repairs — you control the quality and the contractor
• Factor insurability into your valuation
• Remember the timing advantage: electrical work is far cheaper during renovation, so if you're renovating anyway, some of this cost is already in the budget. See when to rewire a house.

If you're already planning to electrify

Add these to the assessment:

• A load calculation for your intended end state — run your own first with the home electrical load calculator
• Panel capacity and spare spaces
• The route and cost for an EV charger circuit — see panel upgrade for EV charging
• Whether load management could avoid a service upgrade — see electrifying without a panel upgrade

Knowing this before closing lets you price the whole plan rather than discovering the constraint later.

The bottom line

A general home inspection checks the panel, samples receptacles and flags visible defects — it doesn't run a load calculation, assess concealed wiring, detect bootleg grounds, or tell you whether the house is insurable. Hire an electrician separately whenever the house is older, has aluminum or knob and tube wiring, has an obsolete panel, or when you plan to electrify. And get insurance quotes with the wiring disclosed before your contingency expires.

Run the numbers with the home electrical load calculator, baseline the house with the home energy score calculator, or read when to rewire a house.