Short answer
The safest way to upgrade a home’s electrical service amperage is to hire a licensed electrical contractor to design the upgrade, pull permits, coordinate the utility shutoff, replace the meter base and main panel with properly sized equipment, upgrade grounding and bonding, and pass inspection before power is restored. Homeowners can help by planning loads, clearing workspace, and choosing future-proof equipment—but the live service work must be left to a pro.
Why upgrade and what size to choose
Common reasons include adding an EV charger, heat pump, induction range, or workshop tools. Many older homes have 60A–100A service. Today, 200A is the typical target for single-family homes. Large homes with multiple HVAC systems or significant EV charging may benefit from a 320A/400A service.
Typical residential service sizes
100A: Modest loads, smaller homes or apartments
150A: Transitional; less common for new upgrades
200A: Standard for most single-family homes today
320A/400A: Large homes, multiple EVs, heavy electric heat
Safe, step-by-step approach
1) Load planning and budget
- Make a list of present and future loads (EV charging, HVAC, range, dryer, hot tub, shop tools).
- Ask your electrician for a NEC load calculation (Standard or Optional method) to justify the new service size and panel spaces.
- Ballpark cost: $2,000–$5,500 for a 100A→200A overhead upgrade; underground or long service runs can add $1,000–$3,000 (trenching, conduit, restoration). Expect 1–2 days onsite once scheduled, plus 1–3 weeks for permits/utility coordination.
2) Contact your utility and AHJ (Authority Having Jurisdiction)
- Verify service availability for the desired amperage.
- Confirm utility-approved meter base type (ring/ringless, lever bypass) and service location.
- Obtain required permits; plan for an inspection prior to re-energizing.
3) Hire a licensed electrician
- They will size conductors, meter base, main breaker, panel, grounding electrode conductor (GEC), and overcurrent protection per code and manufacturer specs.
- They coordinate the utility shutoff (never pull a meter yourself).
4) Choose equipment for the long haul
- 200A panel with 40+ spaces and copper bus (or high-quality aluminum bus) from a major brand.
- Whole-home surge protective device (Type 2) at the main panel.
- AFCI/GFCI protection as required by your local code.
- If EV charging is planned, install a dedicated 50A–60A circuit or a feeder/subpanel in the garage.
5) Site prep you can safely do
- Clear the working area and maintain required clearances: 30 in. wide, 36 in. deep, 6 ft 6 in. high.
- Mount a plywood backboard (fire-rated if required) where the panel/meter will go.
- Label existing circuits to aid transfer; note any nuisance trips or known issues to fix during the upgrade.
6) The electrician’s work (don’t DIY these steps)
- Utility shutoff and meter removal.
- Replace/relocate meter base and service mast or install approved conduit for underground laterals.
- Install new main breaker panel or service disconnect and feeder, re-terminate branch circuits.
- Upgrade grounding and bonding (rods/UFER, water/gas bonding jumpers).
- Torque all lugs to the manufacturer’s specifications, apply antioxidant on aluminum conductors where specified, dress conductors for strain relief, and label everything.
- Inspection and utility re-energize.
Key specs and materials (typical for a 200A dwelling)
Service conductors (dwelling): 2/0 Cu or 4/0 Al (NEC 310.12)
Meter socket: Utility-approved, 200A rated, ring/ringless as required
Main breaker/panel: 200A, 40+ spaces, outdoor rating if exposed
Grounding electrodes: Two 5/8" x 8' rods (or UFER) per local code
GEC sizes (typical): #6 Cu to ground rods; #4 Cu or #2 Al to metal water pipe/UFER (verify locally)
Conduit: Schedule 80 above grade where exposed; per utility/AHJ for service risers
Surge protection: Type 2 SPD at main panel
Tools you’ll see the pro use
- Torque screwdriver and torque wrench (for terminations)
- Conduit bender, fish tape, knockout set
- Label maker, panel directory cards
- PPE: arc-rated clothing, insulated gloves, face shield
For homeowners prepping the area: stud finder, level, drill/driver, exterior-rated fasteners for the backboard, flashlight/headlamp, and a non-contact voltage tester for branch circuit verification (not for service conductors).
Safety considerations
- Service conductors and meter lugs are energized even with the main off. Do not open the meter, pull the meter, or touch service lugs—ever.
- Work must be permitted and inspected. Unpermitted service work can void insurance and delay utility reconnection.
- All terminations must be torqued to spec; loose lugs overheat and fail.
- Aluminum conductors are acceptable when properly sized and terminated; follow lug listings and use antioxidant if specified by the manufacturer.
Pro tips for best results
- Ask for a panel with extra spaces and a factory-installed whole-home surge protector.
- Add a 1–1/4" or 1–1/2" spare conduit from the main panel to the garage/attic for future circuits or EVSE.
- If adding subpanels, keep neutrals isolated and bond only at the service disconnect.
- Confirm overhead mast height clearances and drip loops meet utility standards.
Common mistakes to avoid
- Reusing an undersized meter socket or feeders with a larger main breaker.
- Skipping grounding/bonding upgrades or failing to bond metal water/gas piping.
- Double-lugging neutrals under a single screw, or using tandem breakers where not listed.
- Crowding the panel with short leads or ignoring conductor bending radius.
- Scheduling the outage before permits and materials are ready (can leave you without power overnight).
When to call a professional
- For any work on the service equipment, meter base, or service conductors: hire a licensed electrician.
- Call your utility for meter pulls and service-side work. Homeowners should not attempt it.
- If you’re unsure about load calculations, grounding details, or panel locations, consult your electrician and the local inspector early. A quick plan review often saves time and rework.
Upgrading service is a high-impact improvement that boosts safety, reliability, and capacity. With a permitted plan, the right gear, and a qualified electrician, the process is straightforward and safe—and you’ll be ready for modern loads without headaches.