Panel upgrade vs subpanel
Do I need a panel upgrade or a subpanel?
A subpanel adds circuit space but no capacity. If a load calculation shows your home's demand fits the existing service, a subpanel is the cheaper fix. If adding an EV charger, heat pump or ADU pushes demand over the service rating, you need a service upgrade, which in San Diego means an SDG&E request. Published San Diego pricing for 100A to 200A is $2,800–$4,200 installed.
| Subpanel | Service/panel upgrade | |
|---|---|---|
| Adds capacity (amps) | No | Yes |
| SDG&E involvement | Usually none | Request + disconnect/reconnect |
| Typical trigger | Out of breaker slots | EV, heat pump, induction, ADU |
| City permit | Electrical permit | Electrical permit ($176.57 up to 200A) |
Rule of thumb
- Under 100A service and adding any major electric load: upgrade.
- Ample capacity but a full panel: subpanel.
- Ask about load-management devices that can avoid an upgrade for a single EV charger.
Talk to vetted local pros
Questions San Diego homeowners ask
Is a subpanel cheaper?
Usually, because it avoids utility work, but it cannot add capacity.
Will a subpanel pass inspection for an EV charger?
Only if the load calculation shows the existing service can carry it.
Get a proper load calculation
Licensed electricians will tell you which you need. Free quotes from up to 3.