Panel Upgrade for 8-Unit Building — 250A vs 600A? Square D vs Eaton? Worth the cost?

Question

Hi BP community,

Looking for real-world experience from multifamily owners or investors who’ve done a panel upgrade.

I have an 8-unit building in Santa Clara, CA, and I’ve received 3 quotes to replace the main service panel & meter bank (9 meters total, including common laundry).

What differs across the bids:

• 600A Eaton meter bank 
• Square D panel but amp size not specified
• One bid includes the laundry subpanel
• Some bids don't include permit/engineering/stucco patching
• Prices range from $19K to $38K some not including permit fees.

600A Eaton meter bank

Square D panel but amp size not specified

One bid includes the laundry subpanel

Some bids don't include permit/engineering/stucco patching

Prices range from $19K to $38K some not including permit fees.

Current setup:

• 1960s building
• Gas water heaters
• Shared laundry
• Upgraded kitchen appliances over time
• All tenants have window AC units, 
• No EV chargers yet

1960s building

Gas water heaters

Shared laundry

Upgraded kitchen appliances over time

All tenants have window AC units,

No EV chargers yet

Questions:

• Did you go 250A or 600A on your small multifamily upgrade?
• Did anyone regret not upsizing?
• Any brand preference in the long run (Square D vs Eaton)?
• Anything you wish you’d known about engineering/permit costs before starting?
• Thank you so much.

Did you go 250A or 600A on your small multifamily upgrade?

Did anyone regret not upsizing?

Any brand preference in the long run (Square D vs Eaton)?

Anything you wish you’d known about engineering/permit costs before starting?

Thank you so much.

Chris Seveney · Answer

With window ac units, even with gas water heaters and appliances, I would think 250 would be too small. 400A would be the smallest I would go.Note not an electrician. Long run If I am upgrading I would probably go to the 600A.

Arman Ahmed · Answer

@Shuchi Gupta

Hey Shuchi,

For an 8-unit building, most owners I’ve seen stick with 250A unless you’re planning EV chargers or major future upgrades. Upsizing to 600A is usually overkill and adds significant cost. Between Square D and Eaton, both are reliable, so I’d focus more on contractor familiarity and local service support. Make sure your quotes include permits, engineering, and any wall/patch work—those often add up unexpectedly.