Power Out to the Garage, Shop, or ADU

Most subpanel calls in Rohnert Park start the same way. Somebody ran an extension cord to the garage for a compressor, or converted a bedroom into a rental unit, or got serious about a woodshop, and the existing circuits stopped keeping up. The house was built in a tract wave between the sixties and the eighties with two or three receptacle circuits covering the whole garage, and now there is a table saw, a dust collector, a welder, and a charger all wanting the same wire.

A subpanel is the calm answer to that. It takes one properly sized feeder off the main and gives the far end of the property its own set of breakers, its own capacity, and its own place to shut things off. On a lot of these lots it is a smaller job than people fear, because Rohnert Park’s flat tract parcels make for short, straight, sensible runs.

Work we handle in Rohnert Park

• Detached garage and shop feeds, overhead or trenched
• ADU and junior ADU subpanels with room to grow
• Rental unit and in-law suite distribution
• 240 volt circuits for welders, compressors, and dust collection
• Feeder sizing off a real load calculation
• City permits pulled and inspections attended

The ADU conversion, and where the electrical actually decides things

Rohnert Park’s ranch and split-level stock converts well. Attached garages are generous, back yards are flat, and detached garages sit close enough to the house that a feeder run is short. What usually decides the shape of an ADU project is not the framing. It is whether the existing main service has the headroom to feed a second dwelling once you add a kitchen, a mini-split, a water heater, and a laundry hookup to what the house already draws.

We answer that with a load calculation on the actual house, not a rule of thumb. Plenty of the time a 200 amp service already has the room and the whole project comes down to one feeder and one subpanel. Sometimes it does not, and the honest answer is that the main service has to move first. In Rohnert Park that main-service conversation is also a serviceability-inspection conversation, and we will explain both together rather than dropping the second one on you halfway through.

Junior ADUs and interior conversions are their own case. A JADU sharing a wall with the main house may not need its own service at all, but it usually benefits from a dedicated subpanel so the unit’s breakers are separate from yours and everyone knows what they can shut off.

Detached garages on flat ranch lots

The detached garage feed is the classic Rohnert Park subpanel job. The runs are typically short and the ground is flat, which keeps the trench honest, but a few details decide whether it comes out right. The feeder gets sized for the load you plan to run, not the load you are running today, because pulling a second conductor set through the same trench later costs far more than upsizing once. Aluminum feeders are common on longer runs and are perfectly fine when they are terminated properly with the right lugs and compound.

Detached structures need their own grounding electrode and a separated neutral and ground at the subpanel. That separation is the single most common thing we find wrong on subpanels somebody added over a weekend. It is not cosmetic. Bonded neutrals in a detached subpanel put current on paths that were never meant to carry it, and it shows up as small nuisance shocks long before anything obvious fails.

We also plan the trench around what else is going in it. If a hose bib, a landscape lighting run, or a future EV charger is on the list, one trench can serve all of it if we know before the shovel starts.

The shop version: 240 volt circuits and honest capacity

Garage shops in the F and H sections tend to be ambitious, because those plans came with real garage space. A welder, a dust collector, a compressor, and a decent lighting layout will overwhelm the two general-purpose circuits a tract garage was built with. A subpanel means each of those machines gets a properly sized dedicated circuit and a breaker you can find, instead of everything sharing one twenty amp run and tripping when two motors start together.

We ask what you actually run, and what you expect to buy in the next few years. A 240 volt circuit costs almost nothing extra to include while the panel is open and a great deal to add afterward. Lighting matters too. Shop lighting on its own circuit means a tripped tool breaker does not leave you standing in the dark with a spinning blade.

If the machines are on the wish list rather than the floor, we will size for the wish list. Capacity you did not use is cheap. Capacity you needed and skipped is a second job.

Rentals near Sonoma State, and second units with their own breakers

Sonoma State is inside city limits, and the rental stock around it changes what a subpanel is for. Along Snyder Lane and Southwest Boulevard, and through the M section about a mile from campus, plenty of owners have added a unit or converted part of a house. In those properties the point of a subpanel is separation as much as capacity. The unit’s circuits live in the unit’s panel, labeled, so a tenant can reset their own breaker and nobody has to walk into someone else’s space to do it.

Sections D and E mix single-family with apartment complexes, and owners there often manage a house and a unit at once. Clear distribution is what keeps that manageable. It also matters at sale time, because an inspector reading a properly labeled, correctly separated subpanel asks far fewer questions than one reading a mystery.

We schedule these around tenants, with the outage window given to you well ahead of time so you can notice people properly and avoid the worst weeks of the semester.

Permits, inspections, and doing it once

Subpanel work in Rohnert Park is permitted work, and we pull the permit with the City’s Building Division and meet the inspector on site. If the job also touches the main service, the City’s serviceability requirement comes into play: a certified licensed electrician inspects the existing main service panel and provides the results in writing to the City for the permanent permit record, and if the panel is found serviceable the project can proceed without upgrading the MSP. Grounding is checked at the Electric Meter Release inspection, so any electrode we intend to reuse has to be verifiable and accessible when the inspector is standing there.

Unpermitted subpanels are common and they are a genuine liability. They surface during a sale, during an insurance review, or the first time something goes wrong and somebody looks closely. Correcting one after the fact usually costs more than doing it right the first time, because the wall is closed and the trench is landscaped.

When we finish, the subpanel is labeled circuit by circuit, the directory is filled in legibly, and the feeder and grounding are documented in the permit record. That is the version that stays right for twenty years and reads clean to whoever opens the door next.

Start here

The first visit is free and carries no obligation. We look at your main service, measure the run, ask what you plan to put on the new panel, and tell you what the work involves and exactly what it’ll cost, in writing. Call (707) 684-0024 or send us a note. The gallery shows how our subpanels and feeders come out, and you can read about the rest of our electrical work across Rohnert Park.