Electrical Subpanel Upgrades in San Diego

Exterior electrical panel, meter, and gas meter on a stucco house wall. A window, walkway, and hose are also visible.

Expand Your Power System with Safe, Code-Compliant Subpanel Installation

Running out of breaker space? Installing new appliances or converting a garage? You may need a subpanel upgrade. At Upgrade Electric, we provide licensed subpanel installations and upgrades for residential and commercial properties across San Diego County.



Our subpanel solutions help distribute power efficiently, safely, and in line with California electrical codes — while providing the flexibility your growing property demands.

What Is a Subpanel?

An electrical subpanel (also called a distribution panel) is a smaller service panel that branches off your main electrical panel to serve specific areas, appliances, or systems in a home or building.

Subpanels are often used when:

  • The main panel is full or nearing capacity
  • You're adding a room, garage, or ADU
  • Large equipment or appliances require dedicated circuits
  • You want localized control over a section of the property
  • You’re separating power for a second dwelling unit or rental


A properly installed subpanel provides clean power distribution, additional breaker space, and easier access for electrical control.

Residential Subpanel Installation

Homeowners often need subpanels when upgrading or expanding their homes. Common residential scenarios include:

  • Kitchen remodels
  • Detached garages or workshops
  • Accessory Dwelling Units (ADUs)
  • Pool and spa systems
  • Solar battery systems
  • EV charger installations
  • Outdoor lighting or generator circuits


We assess your electrical load, determine the safest setup, and install subpanels that support your future electrical needs.

Commercial & Multi-Unit Subpanels

For businesses and commercial properties, subpanels are critical for organizing circuits by function or space. We install and upgrade subpanels for:

  • Retail stores and restaurants
  • Office buildings
  • Industrial facilities
  • Apartment complexes and multi-tenant buildings
  • HVAC equipment
  • Backup generator systems


Our commercial subpanel work includes capacity assessments, conduit installation, labeling, grounding, and full code compliance.

Exterior wall with electrical boxes, wires, and air conditioning unit near a sidewalk.

Signs You May Need a Subpanel

Not sure whether a subpanel is the right solution? Here are a few signs:

  • Your main panel is out of breaker space
  • You’re adding a high-demand appliance (EV charger, HVAC, sauna, etc.)
  • You’re wiring a detached structure (garage, shed, ADU)
  • You want to separate power for tenants or new units
  • You plan to add a backup generator or solar battery system

We’ll inspect your system and recommend whether a subpanel is needed — or if a full panel upgrade is more appropriate.

Our Subpanel Services Include:

  • New subpanel installation
  • Subpanel relocation or replacement
  • Circuit planning and wiring
  • Load calculation and breaker balancing
  • Permits and city inspections
  • Grounding, bonding, and surge protection
  • Labeling and electrical mapping


All installations meet the latest California Electrical Code and NEC standards, ensuring safety and long-term reliability.

Integrated Services for Complex Projects

Subpanel installation often goes hand-in-hand with larger upgrades. At Upgrade Electric, we frequently install subpanels in combination with:

  • Electrical panel upgrades
  • Solar panel systems
  • Backup generators
  • EV charger stations
  • Room additions or remodels


Our team ensures all components work together seamlessly under one integrated electrical plan.

Frequently Asked Questions

  • How is a subpanel different from a main panel?

    A subpanel is fed by the main panel and distributes power to a specific part of the property. It does not have a utility meter and cannot be used to power a property on its own.

  • Do I need to upgrade my main panel to add a subpanel?

    Not always. If your current panel has enough capacity and space for a feeder breaker, a subpanel can be added. We’ll assess your system and advise you accordingly.

  • Can I add a subpanel to a detached garage or ADU?

    Yes. Subpanels are ideal for powering detached structures and ensuring separate, localized circuit control.

  • Do subpanels require a permit?

    Yes. All new subpanel installations in California require permits and inspections. We handle the entire process for you.

Areas We Serve

We proudly install subpanels for homes and businesses throughout San Diego County, including:

  • San Diego
  • Chula Vista
  • Jamul
  • La Mesa
  • Spring Valley
  • La Jolla
  • El Cajon
  • San Ysidro
  • Vista
  • Imperial Beach
  • Coronado

Request a Subpanel Evaluation Today

Need more circuit space or planning a home addition? Trust Upgrade Electric for safe, code-compliant subpanel installation and upgrades. We handle everything from load assessments to permitting, with clean, reliable work every time.