Do You Need a Separate Electric Meter for Your ADU?

Understanding ADU Electrical Metering

One of the most common questions homeowners ask when building an Accessory Dwelling Unit is whether they need a separate electric meter. The answer depends on your goals, local utility requirements, and how you plan to use your ADU.

In this comprehensive guide, we'll explore everything you need to know about ADU electrical metering in California—from code requirements to cost implications and the impact on rental income.

California Electric Meter Requirements for ADUs

California law (Government Code Section 65852.2) specifically states that local agencies cannot require a separate utility connection or meter for an ADU. This was designed to reduce barriers and costs for ADU construction.

However, "not required" doesn't mean "not allowed." You have options:

Metering Option	Description	Best For
Shared Meter	ADU connects to main home's electrical panel	Family use, owner-occupied rentals
Separate Meter	Dedicated meter for ADU only	Long-term rentals, tenant billing
Sub-Meter	Secondary meter behind main meter	Tracking usage, cost allocation

Shared Meter vs. Separate Meter: Pros and Cons

Option 1: Shared Meter (Subpanel Connection)

With a shared meter, your ADU draws power from your main home's electrical service. A dedicated subpanel is installed in the ADU, fed by a circuit from your main panel.

Pros:

• Lower installation cost ($1,500-3,500 vs $5,000-15,000)
• Faster utility approval and installation
• No monthly meter fees
• Simpler permitting process

Cons:

• You pay for tenant's electricity
• May need main panel upgrade (see below)
• Harder to track ADU energy usage
• Tenants may not conserve energy

Option 2: Separate Utility Meter

A separate meter means the utility company installs a second meter specifically for your ADU. The tenant receives their own utility bill.

Pros:

• Tenant pays their own electricity
• Encourages energy conservation
• Clearer landlord-tenant boundaries
• May qualify for separate rate tier
• Higher rental income potential (utilities not included)

Cons:

• Higher installation cost ($5,000-15,000+)
• Longer utility approval timeline (4-12 weeks)
• Monthly meter charge ($5-15/month)
• May require service panel upgrade at main home

Cost Comparison: Shared vs. Separate Metering

Cost Category	Shared Meter	Separate Meter
Electrical installation	$1,500 - $3,500	$3,500 - $7,000
Panel upgrade (if needed)	$2,000 - $5,000	$0 - $3,000
Utility connection fee	$0	$1,500 - $5,000
Trenching/conduit	$0 - $1,000	$1,000 - $4,000
Monthly meter fee	$0	$5 - $15/month
Total Upfront	$3,500 - $9,500	$6,000 - $19,000

When Do You Need a Panel Upgrade?

Most California homes built before 2000 have 100-amp or 150-amp electrical service. Adding an ADU often requires upgrading to 200 amps or installing a second service.

Panel Upgrade Requirements

Current Service	ADU Size	Likely Requirement
100 amp	Any size	Upgrade to 200 amp required
150 amp	Under 600 sq ft	May work with load calc
150 amp	Over 600 sq ft	Upgrade likely needed
200 amp	Any size	Usually sufficient

According to the National Fire Protection Association (NFPA 70), electrical load calculations must be performed to ensure safe operation.

Requirements by California Utility

Each utility has slightly different processes and costs:

Southern California Edison (SCE)

• New service application required
• Connection fee: $1,500-3,500
• Timeline: 6-10 weeks
• Contact: SCE New Service

Pacific Gas & Electric (PG&E)

• Application through online portal
• Connection fee: $1,800-4,500
• Timeline: 8-12 weeks
• Contact: PG&E New Construction

Los Angeles Department of Water and Power (LADWP)

• Special ADU program with expedited processing
• Connection fee: $1,200-3,000
• Timeline: 4-8 weeks
• Contact: LADWP

San Diego Gas & Electric (SDG&E)

• New meter application required
• Connection fee: $2,000-5,000
• Timeline: 6-10 weeks

The Sub-Meter Alternative

A sub-meter is a secondary meter installed behind your main utility meter. It tracks ADU electricity usage without creating a separate utility account.

Sub-Meter Benefits

• Cost: $200-500 for meter + $300-500 installation
• No utility approval needed
• Accurate usage tracking
• Can bill tenant for actual usage
• Smart meters offer real-time monitoring

Sub-Meter Considerations

• You still receive the utility bill
• Must manually calculate tenant's share
• California law requires disclosure in lease
• Cannot charge more than actual cost per kWh

Popular sub-meter brands include Sense, Emporia Vue, and Eyedro—all offering smartphone apps and real-time usage data.

Impact on Rental Income

Your metering decision directly affects your ADU rental income:

Scenario	Monthly Rent	Avg Electric	Net Income
Shared meter (utilities included)	$1,800	-$120	$1,680
Separate meter (tenant pays)	$1,700	$0	$1,700
Sub-meter (pass-through)	$1,750	$0	$1,750

The $5,000-10,000 extra cost for a separate meter typically pays for itself in 3-5 years through reduced utility costs and the ability to charge slightly lower (more competitive) rent.

Solar Panel Considerations

If you have or plan to install solar panels, metering becomes more complex:

• Shared meter + solar: ADU benefits from solar generation automatically
• Separate meter + solar: May need second solar inverter or virtual net metering
• NEM 3.0: California's new net metering rules affect ROI calculations

EV Charging Considerations

With California's EV adoption rates climbing, consider future EV charging needs:

• Level 2 EV charger requires 40-50 amp circuit
• May push shared meter configuration over capacity
• Separate meter allows time-of-use optimization for charging

How to Make Your Decision

Choose a Shared Meter If:

• Building for family member use
• Budget is tight
• ADU is small (under 500 sq ft)
• Planning to include utilities in rent
• Main panel is already 200 amps

Choose a Separate Meter If:

• Renting to non-family tenants
• ADU is large (800+ sq ft)
• Want tenants to pay own utilities
• Planning to install EV charging
• May sell property in future (adds value)

Permitting and Inspection Requirements

Regardless of metering choice, electrical work requires:

1. Electrical permit from local building department
2. Licensed C-10 electrician to perform work
3. Rough-in inspection before walls close
4. Final electrical inspection
5. Utility inspection (for new service only)

Your ADU permit will include the electrical scope, so your contractor should handle coordination.

Frequently Asked Questions

Can a city require me to install a separate meter?

No. California law prohibits local agencies from requiring separate utility connections for ADUs. However, utilities can set technical requirements for service.

How long does it take to get a new meter installed?

Typically 4-12 weeks from application approval, depending on utility workload and any required infrastructure upgrades.

Can I charge my tenant more than I pay for electricity?

No. California Civil Code Section 1940.9 requires landlords to charge no more than the actual utility cost. Markups are prohibited.

Do JADUs need separate meters?

No. Junior ADUs (JADUs) are specifically exempt from separate utility requirements as they share facilities with the main home.

Will a separate meter increase my property value?

Generally yes. Appraisers view ADUs with separate utilities as more valuable due to rental income potential and tenant appeal.

Conclusion

The decision between shared and separate electrical metering for your ADU comes down to your specific situation. For most rental ADUs, the higher upfront cost of a separate meter is offset by long-term savings and simplified landlord-tenant relationships.

Key takeaways:

• California law does not require separate meters
• Shared meters save $5,000-10,000 upfront
• Separate meters pay back in 3-5 years for rentals
• Sub-meters offer a middle-ground solution
• Consider future needs (solar, EV charging)

Ready to discuss your ADU electrical plan? Our team can help you evaluate options and connect with licensed electricians.