The ADU is the single most requested project we get calls about right now, and it is not close. A few years back most of our work in Sacramento County was kitchens, additions, and new framing. Today, half the homeowners who reach out want to know whether they can put a second unit on their lot, what it runs, and how long they will be living next to a construction site.

Here is the part nobody tells you straight: California state law has knocked down most of the old local roadblocks. Cities and the County can no longer pile on the rules they used to use to slow these projects down. That is real, and it is good news. But “the state says you can build it” and “here is what it actually costs and how long it actually takes” are two very different conversations. I am Adam, founder of ADC Construction out of Lodi, US Army veteran, General B license through the CSLB. We have built ADUs in Elk Grove, Carmichael, Fair Oaks, and Rancho Cordova, and I am going to give you the honest version.

The 4 ADU Types and What Each Actually Costs in 2026

There is no single ADU price because there is no single ADU. The structure you choose drives almost everything else, so this is where every honest conversation starts. These are real 2026 numbers for Sacramento County, including permits and our labor.

• Attached ADU: $140k to $220k. An addition that shares a wall with your existing house. You save on one wall and sometimes a utility tie-in, but you are still cutting into the existing structure and matching the roofline.
• Detached ADU: $180k to $320k. A separate building, usually 400 to 1,200 square feet. The most flexible and the most expensive, because you are building a complete small home from the foundation up.
• Garage conversion: $80k to $140k. The cheapest path, because the slab, walls, and roof already exist. This is where most budget-conscious homeowners end up, and for good reason.
• Junior ADU (JADU): $40k to $90k. A unit carved out inside the existing home, 500 square feet or less, with its own entrance. Can share a bathroom with the main house in some cases.

What pushes a project to the top or bottom of those ranges? Four things, almost every time: lot constraints, soil and foundation, utility connections, and permitting. I will walk through the last three in detail because they are where most homeowners get surprised.

Sacramento County Permitting: Where the Time Actually Goes

First thing to get straight: jurisdiction. Not everyone in “Sacramento County” pulls permits through the County. Elk Grove is its own city. Citrus Heights and Rancho Cordova are incorporated cities too. Carmichael and Fair Oaks are unincorporated, so those go through Sacramento County directly. Knowing which counter your project belongs at on day one saves weeks.

State ADU law made review ministerial, which means the agency has to issue the permit within 60 days as long as your plans meet code. They cannot send you to a discretionary design-review hearing. That 60-day clock is real and we hold them to it.

Where it gets slower has nothing to do with the permit itself. In parts of the county, especially areas with expansive clay soil, you will need a soils report before the foundation gets approved. That report and the engineering it drives can add weeks and a few thousand dollars, and skipping it is how you end up with a cracked slab in three years. We coordinate the permit submittal, the soils work, and the plan corrections so you are not playing phone tag with the county.

The Utility Connection Problem Nobody Warns You About

A new detached ADU is treated like a new dwelling, and in most cases that means it needs its own electrical meter and panel, its own sewer lateral, and frequently its own water meter. Those are not small line items, and they leave your control once they leave our hands.

SMUD handles electrical for most of the county. A new electrical service connection has its own lead time that runs anywhere from 4 to 12 weeks depending on their backlog. Sewer ties into SRCSD. None of that moves on your schedule or ours.

This is exactly why a $200k detached ADU build can run 6 to 10 months start to finish. The framing, plumbing, electrical, and finish work might only be a few months of that. The rest is permitting on the front and utility connections threaded through the middle. When we quote a timeline, those weeks are built in, because pretending they do not exist is how homeowners end up furious in month five.

Garage Conversions: The Fast Path, With a Few Catches

A garage conversion is the most popular type we build for a reason. The slab, the walls, and the roof are already standing, so you skip the most expensive and slowest part of any build. You also skip most of the foundation and soils complexity.

That said, a garage is not a living space yet, and bringing it up to code is where the work hides. It has to meet Title 24, California’s energy code: real insulation, a proper HVAC solution, and performing windows. A bare garage has none of that. If it was built without a bathroom rough-in, adding one means cutting and trenching the existing slab. That is doable, we do it often, but it is a real cost line.

One piece of good news: the old parking-replacement requirement was eliminated by state law in most situations. That used to kill conversions on small lots. Verify with your specific city, but it is rarely a blocker now. A straightforward garage conversion runs 3 to 5 months.

What ADU Rental Income Looks Like Around Here

A lot of these projects are an investment decision, so here are realistic 2026 ranges for a one-bedroom ADU in our core service area:

• Elk Grove 1BR: $1,400 to $1,800 a month
• Carmichael 1BR: $1,300 to $1,600 a month
• Rancho Cordova 1BR: $1,200 to $1,500 a month

At $1,500 a month on a $200k build, you are looking at roughly 11 years before the unit pays for itself, and then it generates income for as long as you own the property. A permitted, legal ADU also adds to your home’s value in a way that shows up on the appraisal. So you are buying two things at once: monthly cash flow and equity.

Common Questions We Get

Can I build an ADU on any lot in Sacramento County?

Most single-family and multifamily lots qualify under state law. The limits that remain are physical, not bureaucratic: setbacks, lot size, and how the existing house and utilities sit on the property. We can usually tell you in one site visit whether a detached unit fits or whether a conversion or JADU makes more sense for your specific lot.

Does ADC handle everything, or do I need a separate architect?

We handle it as a single project, from plans and permit coordination through the soils report, utility scheduling, framing, plumbing, electrical, and finish. You do not need to hire and manage a separate architect, engineer, and contractor. One contract, one point of contact, one crew responsible for the result.

How long does a detached ADU take start to finish?

Plan on 6 to 10 months for a detached unit. The build itself is the shorter part. Permitting takes up the front weeks and utility connections run through the middle on their own timeline. We build those waits into your schedule up front so there are no surprises.

Can I finance an ADU with a construction loan, or do I need cash?

You do not need cash sitting in the bank. Most of our ADU clients use a construction loan, a renovation loan, or a HELOC against the equity in their primary home. Lenders have gotten comfortable with ADUs because the finished unit adds value and rental income. We provide the detailed scope and cost breakdown your lender will want to see.

What is the minimum lot size for a detached ADU in Elk Grove?

State law removed most hard minimum-lot-size rules. What matters is whether the unit fits within the required setbacks once your existing house is accounted for. On a tight lot a smaller footprint or a garage conversion is often the better play. Since Elk Grove is its own city, the permit goes through the City of Elk Grove, and we handle that submittal.