Northridge, CA · June 2025 – June 2026 · LADWP / LADBS

The array was ready. The building was not.

A new two-storey detached ADU with an attached two-car garage, and a 2.32 kilowatt array on it. The calendar belonged to the construction, not to the solar.

When solar is part of a new building rather than an addition to an existing one, the array does not set its own schedule. The interconnection can be filed early, but the inspections, the meter and the permission to operate all wait for the building to be finished.

At a glance

System

2.32 kW AC-CEC

Building

New two-storey detached ADU

Garage

Attached, two cars

Interconnection filed

June 2025

Permission to operate

June 2026

Array size

Small — one hip roof

Utility / AHJ

LADWP / LADBS

The story

This one is a new building, not a retrofit. A detached two-storey accessory dwelling unit at the back of the lot, with an attached two-car garage underneath it, and a small array on the hip roof above.

Because it is new construction, the solar was designed into the building rather than added to it. The conduit runs are inside the framing, dropped down the stud bays before the insulation and the drywall went in. From the finished building you cannot see where the array connects, which is the practical benefit of doing it in this order and the only moment it is possible.

What the page is really about is the calendar. The interconnection request was filed in June 2025 and the utility fees were paid the same week. The building department inspections came in February 2026. The utility's site evaluation followed in April. The installation was released at the start of June and permission to operate came on the tenth.

A year on the calendar for a small array. The gap is the building: the inspections, the meter and the sign-off all wait for the structure the array sits on to be finished. Filing the interconnection early is what keeps the solar from becoming the thing everyone waits for at the end.

If you are building an ADU and thinking about solar, the useful decision is not whether to do it but when to have the conversation. Before the walls close is cheap. After they close is a retrofit on a brand new building.

How it ran

A year on the calendar, set by the building rather than by the array.

What we did

• Designed the array into a building that was still being framed.
• Ran the conduit inside the stud bays before insulation and drywall.
• Filed the interconnection request while the building was under construction.
• Installed rails and modules once the roof was on.
• Carried the interconnection through to permission to operate at 2.32 kilowatts AC-CEC.

System specifications

Is your project like this one?

• You are building an ADU and wondering when to raise solar.
• You want the conduit hidden rather than surface-run on a new building.
• You are being told solar will delay your project.
• You want to know what size of system a small second dwelling actually takes.
• You are coordinating trades and want the solar inside the build, not after it.

Cali Energy in Northridge

Frequently asked questions

When should solar be designed into a new ADU?

Before the walls close. On this project the conduit went down the stud bays ahead of insulation and drywall, so nothing is surface-run on a brand new building. After the walls close the same work becomes a retrofit.

Why did this take a year?

Because the building took a year. The interconnection was filed in June 2025 and permission to operate came in June 2026. The inspections, the meter and the sign-off all wait for the building to be finished.

How big a system does an ADU take?

It depends on the roof it has. This one is 2.32 kilowatts AC-CEC on the hip roof of a two-storey unit with a garage below.

Does solar delay an ADU project?

On this project the solar was filed while the building was still going up and the conduit went in before the walls closed, so it was not the item everyone waited on at the end. Raising solar after a building is finished turns the same work into a retrofit.

Can the ADU have its own meter?

That depends on how the dwelling is served, and it is decided with the utility rather than on the roof. The interconnection on this project was carried through to permission to operate at 2.32 kilowatts AC-CEC.

Does Cali Energy work with builders in Northridge?

Yes, including new construction where the solar is designed in alongside the framing. Cali Energy holds B, C-10 and C-39 classifications under CSLB #1032379.

What this would look like on your roof

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This timeline reflects this property and this permitting path. Updated September 2026.