Why You Want a 400-Amp Service in 2026

For fifty years, a 200-amp main service was the residential standard. It powered everything a typical family needed — a few HVAC units, a clothes dryer, an oven, lights, plugs. Then, in roughly the last decade, electrical loads in new homes have exploded. Two EVs charging. Heat pumps replacing gas. Induction replacing gas cooktops. Solar pushing back to the grid. Battery storage. The new electrical landscape needs more power than 200 amps comfortably provides — and spec'ing 400 amps at new construction is dramatically cheaper than upgrading later.

What your house actually pulls

A typical 200-amp service supports about 48 kilowatts of continuous load (200 amps x 240 volts x 0.80 demand factor / 1000 = 48 kW continuous). Let's add up what a modern luxury home actually draws:

• Two HVAC condensers (5-ton each, ~6 kW per unit): 12 kW
• Two EV chargers (40A each, 7.7 kW each): 15.4 kW
• Tankless water heater (electric, 27 kW peak / ~6 kW typical): 6 kW typical
• Induction cooktop (10 kW peak): 8 kW estimated
• Electric oven (5 kW): 5 kW
• Heat pump water heater (4.5 kW): 4.5 kW
• Dryer (5 kW): 5 kW
• Pool equipment, hot tub, dishwasher, washer, microwave, lighting: 10 kW

That's roughly 65–70 kW of total connected load. With diversity factors (not everything runs simultaneously), the practical demand might be 35–50 kW continuous — right at the edge of 200-amp service capacity, with no headroom for future expansion.

Why upgrade now is cheap; upgrade later is expensive

At new construction, upgrading from 200 amps to 400 amps adds roughly:

• Larger main panel (or two 200-amp panels): $800–$1,500 upcharge
• Larger service entrance conductors (4/0 vs. 2/0): $500–$1,000 upcharge
• Larger meter base and weather head: $200–$400 upcharge
• Permit/utility coordination: included in normal service install

Total: roughly $1,500–$3,000 incremental cost during construction.

Retrofitting a 200-amp house to 400-amp service after the fact:

• New panel, conductors, meter base: $4,000–$8,000
• Trenching for new service entrance: $2,000–$10,000+
• Possible utility upgrade fees: $0–$5,000
• Permits, inspections, coordination: $1,000–$2,000
• Possible interior wall work for new panel location: $1,000–$5,000

Total: $8,000–$30,000 retrofit cost. The 3x–10x cost differential is why we tell every client: spec 400 amps now, even if you can't articulate why you'll need it.

What about 320-amp or 240-amp services?

Some utilities offer 320-amp services (often metered as "200-amp continuous" but with the ability to pull more for short periods). These are a half-step but cost roughly the same as a true 400-amp install. We rarely spec them — if you're upgrading from 200, go to 400.

Panel layout matters too

A 400-amp service usually means either one 400-amp panel or two 200-amp panels (one main, one sub). The two-panel approach has advantages:

• More breaker slots (40–42 per panel x 2 = 80–84 total slots) — future expansion built in
• Can locate panels strategically (one in garage, one in mechanical room) to reduce home-run wire lengths
• Allows clear circuit grouping (one panel for HVAC and EV, one for everything else)

Surge protection — do this once

While you're upgrading your electrical service, install whole-house surge protection. A Type 2 surge protector at the main panel costs $300–$800 installed and protects every circuit in the house from utility-side voltage spikes (lightning, transformer faults). Combined with Type 3 surge protectors at sensitive electronics (TV, computer), you have layered protection that prevents thousands of dollars of electronics damage.

We won't install a new electrical panel without whole-house surge protection. It's malpractice in 2026 not to.

What about generators and battery backup?

If you're spec'ing 400 amps, also think about whole-house backup. Two options:

• Whole-house generator (natural gas or propane): Generac, Kohler, or Cummins. Sizes from 18kW (essential loads) to 48kW+ (whole house). Installed cost $8,000–$25,000.
• Battery storage (Tesla Powerwall, Enphase IQ, Generac PWRcell): 10–40 kWh of storage per home. Pairs with solar to provide energy independence. Installed cost $15,000–$60,000+ depending on size.

Battery is the modern preferred answer for most homes — quieter, no fuel, integrates with solar, eligible for tax credits. The integration is easier when planned during electrical rough-in than retrofitted.

The conversation with your electrician

Tell your electrician: 400-amp service, two 200-amp panels, whole-house surge protection, conduit reserved for future solar inverter and battery backup. Total upcharge over a standard 200-amp install should be $3,000–$6,000. That's the price of a refrigerator. The headroom you buy is permanent.

— Daniel Caro, Construction Manager. Twenty years running jobsites — foundation, framing, mechanicals, and the unglamorous details that decide a great home. Get the free Ultimate Home Building Checklist for the field-tested list we walk every Angel home through.