Electrical contractors in the United States

Permits and inspections are part of the job

Most electrical work beyond swapping a device for an identical one is permitted and inspected work. The usual sequence is a permit pulled before the work starts, a rough-in inspection while the wiring is still visible and before any wall is closed, and a final inspection before the circuit is energised and the permit is signed off. The inspector works for the local building department, not for the contractor and not for the utility.

The inspection is the part homeowners most often agree to skip, and it is the part worth keeping. It is the only independent look anyone takes at the work, it is normally already inside the permit fee, and its record is what a buyer's inspector, an insurer or an appraiser will look for later. A quote that is cheaper because it does not include a permit is not a cheaper job; it is a different one.

What triggers a permit varies by jurisdiction, and this site publishes no local permit schedule for that reason. The code the inspector applies is the National Electrical Code as the state or the city has adopted and amended it, which is why two neighbouring towns can genuinely give different answers.

Source: National Fire Protection Association, codes and standards

The panel question is a load question

A service panel is where the utility's supply lands in the building and where it is divided into circuits. Its rating, usually one hundred, one hundred and fifty or two hundred amps, describes the whole house rather than any one circuit. Upgrading it is a bigger job than replacing a box: it normally involves new service-entrance conductors, a new meter base, an updated grounding and bonding arrangement, and a scheduled disconnect and reconnect by the utility.

Whether a house needs one is settled by a load calculation, not by the age of the panel or by how full it looks. A panel with no free spaces can often take tandem breakers or a subpanel. A panel with free spaces can still be at its limit once a heat pump, an induction range and a vehicle charger are added. Panels from particular manufacturers and eras are replaced on their own merits rather than for capacity, and that is a separate conversation from the amperage.

Ask for the calculation, in the same way you would for heating and cooling equipment. The number that comes out of it is the reason for the work.

Source: U.S. Department of Energy, electricity in the home

Aluminium branch wiring in houses of a certain age

Houses wired in a window running roughly from the mid-nineteen-sixties to the early nineteen-seventies sometimes have solid aluminium conductors on ordinary fifteen and twenty amp branch circuits. Aluminium expands, contracts and creeps differently from copper, so the failure mode is at the connections, at outlets, switches and splices, rather than in the middle of a run.

Whole-house rewiring is one remedy and not the only one. Repair methods that address the connections exist, and connectors and devices rated for use with aluminium conductors are made for the purpose. An assessment by someone who has worked on it before is the first step, and a home inspection report noting aluminium branch wiring is a reason to get that assessment rather than a verdict on the house.

This is also the single most common reason an insurer asks a question about a house's wiring, so it is worth knowing the answer before the renewal rather than after it.

Source: U.S. Consumer Product Safety Commission, electrical safety

Vehicle chargers are the new load in old houses

A level 2 vehicle charger is a dedicated circuit sized for a continuous load, and it is the addition most likely to turn a comfortable service into a tight one. The work is a permit-and-inspection job in most jurisdictions, and the question that decides the price is not the charger but whether the existing service can carry it.

Where it cannot, load-management devices that shed the charger when the rest of the house draws heavily are an alternative to a service upgrade, and are cheaper. An electrician who prices only the upgrade has answered a narrower question than the one you asked.

Source: U.S. Department of Energy, charging an electric vehicle at home

What the licence figures on this site do and do not cover

Electrical is the trade where a reader is most likely to be reading the licensed share as a safety signal, so the size of what that share does not cover is stated here in words rather than left as a percentage: this site counts electrical records across all fifty states and the District of Columbia, and 2 of them publish a business-level licence source this site can join a listing to. In the rest, the licensed share is shown as not published rather than as zero, and no record is described one way or the other on the strength of a file that does not exist. Across the states that do publish one, 25.2% of the records counted there carry at least one active licence covering this trade. That is a measurement of how well two files join, and it says nothing about any particular business. Read the other direction as well: 34,903 active licences covering this trade have no matching record in open place data at all, so they appear in no list on this site.

Electrical questions answered on this site

• Do you need a 200-amp panel upgrade?
• A breaker keeps tripping: how urgent?
• Aluminum branch wiring in an older house: what to do?
• Installing a level 2 EV charger: permit, circuit, and what the labor costs