Winnetka, CA · 2023 · LADWP / LADBS
Seven hundred square feet. Two kilowatts.
A detached accessory dwelling unit of 753 square feet in Winnetka, built on an existing lot and metered separately from the house. This is what the array on it came out at.
This 753-square-foot detached ADU was separately metered, carried its own interconnection work request, and received a 1.95 kilowatt AC-CEC system on one usable roof plane. What a different unit needs depends on its own load and its own roof.
At a glance
- Building
- Detached ADU, 753 sq ft
- System
- 1.95 kW AC-CEC
- Metering
- Separate from the main house
- Interconnection
- Its own work request
- Roof
- Composition shingle
- Permit
- Detached ADU, certificate of occupancy issued
- Battery
- None
- Utility / AHJ
- LADWP / LADBS
The story
A detached accessory dwelling unit on an existing Winnetka lot: 753 square feet, built under the city's ADU rules and signed off with its own certificate of occupancy. It is a separate building with a separate meter, which makes it a separate utility customer.
This 753-square-foot detached ADU received a 1.95 kilowatt AC-CEC system on one usable roof plane. That is a project example rather than a general sizing rule: what a particular unit needs comes out of its own load, and what fits comes out of its own roof.
Because the unit is metered on its own, the interconnection is its own work request rather than an addition to the main house's record. Its production belongs to its own account, which is what matters when the unit is rented.
Everything else is a normal installation at a smaller scale: rails, flashed attachments, a combiner and a disconnect, sized for what a single small building draws.
The useful thing to take from this one is the number. If you are building a detached ADU and wondering what solar on it costs and covers, the answer starts with a roof of about seven hundred square feet and a system around two kilowatts — not a copy of whatever is on the house in front of it.
How it ran
| 2023 | Detached ADU completed and its certificate of occupancy issued |
|---|---|
| 2023 | Interconnection application filed for the unit on its own work request |
| 2023 | Utility site evaluation completed |
| 2023 | Interconnection review completed |
| 2023 | Permission to operate |
The unit was finished and separately metered before its solar was interconnected.
What we did
- Sized the array to the unit's roof and load rather than to the main house.
- Interconnected the unit on its own work request, matching its separate meter.
- Installed rails and flashed attachments on the unit's roof plane.
- Set the combiner and disconnect for a single small building.
- Carried the unit through the utility's review to permission to operate.
System specifications
| Building | Detached accessory dwelling unit, 753 sq ft |
|---|---|
| System | 1.95 kW AC-CEC |
| Metering | Separate meter from the main house |
| Interconnection | Its own utility work request |
| Roof | Composition shingle |
| Battery | None |
| Utility / AHJ | LADWP / LADBS |
Is your project like this one?
- You are building a detached ADU and want to know what solar on it involves.
- You have been quoted a house-sized system for a small building.
- Your ADU will have its own meter and you want its production on its own account.
- You are renting the unit out and want its bill to stand alone.
- Your Winnetka property is served by LADWP, while permits are handled by LADBS.
Cali Energy in Winnetka
Winnetka is inside City of Los Angeles boundaries: permits run through LADBS, interconnection through LADWP.
Detached ADUs on existing lots are common here, and they raise a question the main house never had to answer.
This installation is on the Winnetka projects page alongside the others, and what the work covers is set out on the Winnetka service area page.
- License and classifications: CSLB #1032379
- Official reference for this process: Los Angeles City Planning — housing policies and ADUs
- Official reference for this process: LADWP Electric Service Requirements
Frequently asked questions
How much solar does a detached ADU need?
This 753-square-foot detached ADU received a 1.95 kilowatt AC-CEC system on one usable roof plane. It is a project example, not a general sizing rule — the size follows the unit's own load and its own roof rather than the property it sits on.
Does a detached ADU get its own solar interconnection?
Where it is separately metered, yes — it is its own utility customer and its own work request, which is the structure on this property. LADWP also allows an ADU to remain behind the primary residence's meter, which would change that.
Can solar go on an ADU that is still being built?
It can be installed, but the interconnection waits. The utility processes a solar request for a new dwelling after that dwelling is complete and has permanent power.
Is a small system worth it on an ADU?
That depends on the unit's own bill. On this project the system came out at 1.95 kilowatts AC-CEC, and the design and permitting work was the same as on a house.
Does Cali Energy install solar on ADUs in Winnetka?
Yes — detached units, attached units and two-unit developments. Winnetka is inside City of Los Angeles boundaries, so permits run through LADBS and interconnection through LADWP.
What this would look like on your roof
Every number on this page came off a real job in Winnetka, CA — not a brochure. Tell us your utility, your roof and what your bill looks like now, and we will model your own version of it before you commit to anything.
Or call +1 (323) 844-7777 · Cali Energy, Northridge · CSLB #1032379 (B, C-10, C-39) — design, permits, install and electrical under one licensed contractor.
Related
This timeline reflects this property and this permitting path. Updated September 2026.