Do You Need an Electrical Panel Upgrade for Your Home Renovation?

Most renovation plans start with the fun parts. New cabinets, a better layout, a bathroom that finally fits two people. The electrical panel out in the garage or down the hallway rarely comes up until someone asks what you plan to plug in, and whether the house can actually carry it.

That question is where an electrical panel upgrade enters a home renovation. Your panel is the point where power from Idaho Power gets divided and sent out to every room, outlet, and appliance you own. Add an electric range, a heat pump, a hot tub, or an EV charger, and you are asking that panel for more than it was originally built to give.

Checking this before demo starts saves you from the expensive version of the problem: drywall closed up, cabinets set, and an inspector telling you the service will not carry the new load. Below we walk through how electricians decide whether your panel needs upgrading, what the work includes and what drives the cost, and how permits and inspections fit into your timeline.

Does a Home Renovation Require an Electrical Panel Upgrade?

Sometimes, but not always. A renovation requires a panel upgrade when the added load is more than your existing service can safely carry, when the panel has no space left for new circuits, or when the panel itself is unsafe or obsolete. If none of those apply, the panel you have may be perfectly fine for the project.

Electricians settle this with a load calculation, the method set out in Article 220 of the National Electrical Code. It adds up your home’s square footage, the appliances already in place, and everything the renovation will add, then measures that total against your service size. Idaho enforces the 2023 edition of the National Electrical Code, effective July 1, 2024, so any panel work in Boise has to meet that standard.

Worth clearing up, because it comes up on nearly every estimate: panel age on its own is not the trigger. Most panels outlast the breakers inside them, and home inspection guidance puts those protective devices at roughly 30 years. A well-maintained 1990s panel with open breaker slots can support a kitchen remodel without any trouble. Age matters when it shows up alongside something else. The Electrical Safety Foundation International recommends a professional inspection for any home over 40 years old, or before a major addition, which is a reasonable rule to work from.

These are the conditions that genuinely call for an upgrade:

• Your calculated load is higher than your service rating. A 100-amp service supporting central air, an electric dryer, and a water heater has very little left to give a new 50-amp range.
• The panel is physically full. No open slots and no room for tandem breakers means there is nowhere to land the new circuits your renovation needs.
• The panel is unsafe or obsolete. A fuse box instead of breakers, rust or heat damage, scorching around the breakers, or a panel brand with a documented failure history such as Federal Pacific Stab-Lok or Zinsco.
• You are planning ahead. If a second phase is coming, doing one electrical panel upgrade now costs less than doing the work twice.

If your home checks none of those boxes, an honest electrician will tell you the panel stays and the project moves on.

How Much Power Your Renovation Actually Adds

The reason renovations strain panels is that modern upgrades are heavy on 240-volt circuits. A single addition can claim a meaningful share of a 100-amp service. Here is what the common ones typically draw:

Renovation Addition	Typical Circuit
Electric or induction range	40 to 50 amps, 240V
Heat pump or new HVAC system	30 to 60 amps, 240V
Hot tub or spa	30 to 50 amps, 240V
Level 2 EV charger	40 to 60 amps, 240V
Kitchen small appliance circuits	Two 20-amp circuits minimum, 120V
Heated bathroom floor	One dedicated 20-amp GFCI circuit, 120V
Home office	One or two 20-amp circuits, 120V
Room addition or ADU	Often a subpanel plus new circuits

Run the math and the pattern shows up fast. A home office or a heated bathroom floor adds very little and rarely changes anything. But a kitchen remodel with an induction range, plus a Level 2 charger in the garage, can add 80 to 110 amps of new demand to a house that only has 100 amps coming in. That is the combination that turns a remodel into a service upgrade.

Not every one of those additions runs at full draw at the same time, which is exactly what a load calculation accounts for. It is also why guessing from a list like this one is no substitute for having someone measure.

100-Amp vs 200-Amp: What Most Boise Renovations Need

For most Boise homes taking on a renovation, 200-amp service is the target, but the honest answer depends on what you are adding and what you already have. The age of your home is a useful starting clue. North End homes were largely built between the 1890s and the 1940s, and Bench neighborhoods like Hillcrest and Randolph-Robertson went up mostly from the 1940s through the 1960s. Homes from those eras started with much smaller services than we install today, though many have been upgraded at some point since. Newer subdivisions in Meridian, Kuna, Star, and Middleton generally came with 200-amp service from the start, so a remodel out there more often means adding circuits than replacing a panel.

When 100-Amp Service Is Still Enough

Plenty of renovations finish on a 100-amp service with no panel work at all. If your load calculation comes in under your service rating, your panel has open breaker slots, and the equipment is in sound condition, there is no code reason and no safety reason to replace it. Lighting updates, added outlets, a home office, a bathroom remodel without heated flooring, and a kitchen refresh that keeps a gas range all tend to fit inside what you already have.

There is also a middle path worth asking about if an EV charger is the only thing pushing you over the line. Load management devices let a charger share capacity with other large loads, which can avoid a service upgrade entirely. It is not right for every home, but it belongs on the table before you commit to the bigger job.

When Your Renovation Calls for 200-Amp Service

Add large 240-volt equipment and a 100-amp service runs out of room fast. 200-amp service is the practical answer when your renovation includes an electric or induction range, a heat pump, a hot tub, a Level 2 EV charger, or some combination of them, and it is effectively required when you are building an addition or an ADU that needs its own subpanel.

A full panel, a fuse box, or a panel with a documented failure history lands you here too, regardless of the load math, because that equipment has to be replaced either way. Worth planning around: Idaho Power requires advance approval for any single residential load over 6 kW, which covers most Level 2 EV chargers, welders, and electric space or water heating.

Both paths are legitimate, and a load calculation is what tells you which one your home is on.

What an Electrical Panel Upgrade Actually Includes

An upgrade is more than swapping the gray box on the wall. Depending on what your electrician finds behind the cover, the scope can include:

• The panel enclosure and a new set of circuit breakers
• New service entrance conductors, the cable carrying power from the meter into the panel
• A new meter base or meter socket
• The service mast and weatherhead where the utility line connects to the house
• Updated grounding and bonding to meet current code
• A change in service size, such as 100 amps to 200 amps, which is what makes the job a service upgrade rather than a panel replacement

Two misconceptions come up on nearly every estimate, and both are worth clearing up before you budget. The first is that a panel upgrade means rewiring the house. It usually does not. The wiring already inside your walls generally stays exactly where it is, and only the service equipment changes.

The second is that a bigger panel means more power. Capacity is set by your service size and the conductors feeding the panel, not by how many breaker spaces it has. A large panel on a 100-amp service is still a 100-amp service.

Cost tracks scope, which is why two houses on the same street can come back with very different numbers. The service size you need, where the panel sits and how accessible it is, whether the meter base and service entrance cable have to be replaced along with it, and the permit requirements for your address all move the total. Homes built before the 1980s tend to land on the higher end, because the equipment feeding the panel is usually as old as the panel itself. All 4 You Electrical evaluates all of it on site and provides a written estimate at no cost, so you have a real number to build the rest of your renovation budget around.

Why an Electrical Panel Upgrade Requires a Licensed Electrician in Idaho

In Idaho, this is not a preference. It is the law. Idaho Code allows a homeowner to pull an electrical permit only for their own residence, and only if they personally perform all of the work. The moment you bring in help, that person has to be a licensed Idaho electrical contractor pulling the permit in their own name.

Boise adds another layer. The City can void a homeowner’s electrical permit if it becomes clear the homeowner lacks the knowledge to complete the installation, and at that point you are hiring a licensed contractor and paying a second permit fee anyway. Panel work also has to meet the 2023 National Electrical Code, and Idaho Power will not restore permanent power until the installation passes inspection.

Three separate approvals have to line up in the right order, and a missed step means your power stays off longer than planned. Here is what a licensed electrician is handling on your behalf:

• Running the load calculation under NEC Article 220 that determines your service size
• Pulling the permit under the right jurisdiction, whether that is the City of Boise or the state
• Coordinating Idaho Power’s disconnect and reconnect, plus advance approval for any load over 6 kW
• Bringing grounding, bonding, and service equipment up to current code
• Scheduling the inspection and being on site to answer for the work

All 4 You Electrical is family-owned and locally operated, with over a decade of electrical work across Boise and the Treasure Valley. Our licensed electricians handle the permit, the utility coordination, and the inspection as part of the job, so the only thing you track is your renovation timeline.

FAQs About Electrical Panel Upgrades and Home Renovation

How long does an electrical panel upgrade take?

The panel swap itself usually takes four to eight hours, and your power will be off for most of that time. Counting the permit, Idaho Power’s disconnect and reconnect, and the inspection, most projects run several days to about a week from start to finish.

Do I need a permit for an electrical panel upgrade in Boise?

Yes. Panel upgrades and service changes require an electrical permit, and it has to be in place before work begins. Wiring cannot be closed up until it has been inspected and approved, and Idaho Power will not restore permanent power until the installation passes. Your electrician handles all of it.

Can I install a subpanel instead of upgrading my main panel?

Sometimes. A subpanel adds breaker spaces, which solves a full panel, but it does not add capacity to your service. If your load calculation shows you are near your service limit, a subpanel will not fix it. If you have capacity and simply ran out of room, it can be the cheaper answer.

How many amps do I need for a kitchen remodel?

It depends on the appliances. A kitchen refresh that keeps a gas range often fits within your existing service. Add an induction or electric range at 40 to 50 amps, plus the two 20-amp small appliance circuits the code requires, and a 100-amp service can run short fast.

Does a home addition require an electrical panel upgrade?

Often, yes. An addition adds square footage, lighting, outlets, and sometimes its own heating and cooling, all of which raise your calculated load. Many additions also need their own subpanel. Whether the main service has to grow depends on the load calculation, not the square footage alone.