Golden State ADUs is a full-service ADU builder for Loomis homeowners, handling design, structural and civil engineering, permitting, and construction with one accountable in-house team. Accessory dwelling units are the only thing we build. We are licensed and bonded (LIS. #1125656), every project carries a 10-year structural integrity warranty and a 1-year fit-and-finish warranty, and we have been trusted by 100+ happy customers.
We work out of Roseville in the Sacramento region, close enough to Loomis to stand on your lot when it matters, and we build to the Town of Loomis standards rather than generic California talking points. Permits for work inside incorporated Loomis run through the Town of Loomis Building Department, with applications submitted at Town Hall, 3665 Taylor Road. That submittal is ours to manage, not yours.
An accessory dwelling unit (ADU) brings design, engineering, and permitting questions that are not routine for a conventional home remodeling crew. Because our expert team of designers, engineers, and builders sits under one roof, nothing gets handed off to a stranger and reinterpreted in the field. Fewer handoffs means fewer misunderstandings between the people drawing your ADU and the people building it.
Start with a free consultation: a 1-hour project walkthrough on your property. Call (916) 909-2387 and we will look at your Loomis lot, your goals, and what is genuinely buildable before anyone talks numbers.
Accessory Dwelling Unit Design, Permitting and Construction in Loomis
We handle every phase of your Loomis ADU in-house, including architectural design, structural engineering, and civil engineering through our design arm, Golden State Design and Engineering. No separate architect, no separate engineer, no separate builder for you to chase. Call them granny flats or tiny houses if you like; the code calls them accessory dwelling units. ADU construction costs vary widely by build type, so we start by matching the right ADU type to your lot, your budget, and how you plan to use the unit.
Detached ADUs and Custom ADUs
A detached ADU is a standalone unit in your backyard, and Loomis permits detached ADUs up to 1,200 square feet. That ceiling applies to the total as well: two ADUs on one property cannot exceed 1,200 square feet combined, so the layout conversation starts with how you want that allowance spent.
Detached ADUs are the most requested configuration we see in Loomis, largely because they give tenants or family members a genuinely separate front door. We design studios through three-bedroom units, and these are custom ADUs drawn to your building envelope rather than plans pulled off a shelf. Where the trees sit, where the setbacks land, where utilities run, and where the sun hits in the afternoon all shape the footprint. Your Loomis ADU should look like it belongs on your property, because it was drawn for your property, and that fit is a large part of what protects your property value at resale.
Attached ADUs, Internal Conversions and Added Living Space
An attached ADU shares a wall with your main house, which can shorten utility runs and preserve more open yard. An internal ADU is built inside the existing home structure, carving independent living space out of square footage you already own. Attached ADUs and internal conversions are both strong options on tighter Loomis parcels, where a detached footprint would eat the usable backyard.
A junior ADU (JADU) is capped at 500 square feet and carries an owner-occupancy condition: the owner must live in either the primary dwelling or the JADU. We will tell you plainly at the walkthrough whether that condition fits your plans before you invest in drawings.
Garage Conversion ADU: New Living Space From Existing Structure
A garage conversion ADU is usually the most cost-effective route, because the foundation, walls, and roof already exist. What changes during construction is everything that makes a garage a home: insulation, egress, weather sealing, a code-compliant floor assembly, plumbing, electrical, HVAC, and a separate entrance.
Before we draw anything, we verify existing site conditions. Slab condition, wall framing, header spans, panel capacity, and the route from the garage to sewer or septic all determine whether a conversion is the smart path or whether one of our detached ADUs gives you more livable space for the same spend.
Architectural Design, ADU Models and In-House Engineering
Your architectural plans, structural calculations, and civil engineering are produced by one team that talks to each other daily. That matters in Loomis, because the Town requires an ADU’s architectural style, exterior materials, and colors to be compatible with the primary dwelling. Compatibility is a design problem, not a paperwork problem, and it is far easier to solve at the drawing stage than after a correction notice.
Our ADU models range from compact studios to three-bedroom layouts, and we favor modern design that feels larger than its square footage: generous natural light, thoughtful storage, and a separate entrance positioned for real privacy. Door swings, window placement, and storage should all feel intentional. Having engineering in-house also gives us room for innovative solutions when site constraints fight back. Those contemporary exteriors still get a Loomis-appropriate treatment, because the ordinance asks for it and because the unit should read as part of your home. Local building departments enforce their own code requirements, and we draw to those nuances from the first sketch.
Permitting and Compliance, Done for You
Permits, paperwork, compliance: done for you. We prepare and submit the permit application and plan set to the Town of Loomis Building Department at Town Hall on Taylor Road, respond to written corrections, and track the file until it is issued. Compliance with local ordinances is part of the design, not an afterthought bolted on at submittal. Permit fees are part of the budget conversation we have upfront, so the number you plan around is the real one.
Where your ADU will use an onsite wastewater system or a well, we work closely with local authorities and coordinate the required Placer County Environmental Health review. We also carry the Town of Loomis business license obligation that applies to anyone performing work in Town, which matters because Loomis states a building permit cannot be processed without it. Construction begins only after permits are approved.
Retirement ADUs, Passive Income Rentals and Multigenerational Living
Many homeowners come to us with a person in mind, not a building. Parents who should be close but not down the hall. An adult child saving for a first home. A guesthouse that doubles as a home office the rest of the year. Call it a parents ADU, a guest suite, or a rental unit, the brief is the same: an ADU is a practical way to house aging parents with real privacy on both sides, and it gives a family flexible arrangements that change as the years do.
Potential rental income is the other common driver, and a well-built ADU can add meaningful value to your property. Plan it correctly from day one: Loomis prohibits renting an ADU or JADU for fewer than 30 consecutive calendar days, so long-term tenancy is the compliant path here. We design for that reality, with durable finishes and a layout that holds up to years of occupancy.
Comparing ADU Contractors? Why Loomis Homeowners Choose Golden State ADUs
Homeowners choose us because one team owns the entire process, and because we build to Loomis’s actual standards instead of recycled statewide generalities. When you compare builders, ask each one which state and local regulations they have worked under, and ask specifically about Placer County zoning, Placer County Environmental Health review, and the Town’s own ordinance. The answers separate the specialists quickly.
Here is a question almost no one raises: anyone performing work in Loomis must hold a Town of Loomis business license, and the Town says a building permit cannot be processed without one. An ADU builder who learns that at submittal has already cost you weeks. We treat it as a precondition, not a surprise.
Ask us for recent ADU references, and ask to see completed units. Our portfolio exists so you can judge our finish quality and layout thinking against your own taste before you commit. We build ADUs and nothing else, which means the person designing your unit has solved the same site constraints many times over, from the Sacramento, CA suburbs to the Bay Area edge of our service map, and the entire crew on your job answers to the same project manager.
The code knowledge shows up in the drawings. Loomis generally requires 10 feet of separation between an attached or detached ADU and another building, though that distance may be reduced to six feet where there are no Building Code health and safety concerns. On a tight parcel, four feet of relief is the difference between a two-bedroom and a studio. Knowing when the reduction applies is the kind of detail that decides feasibility.
On budget, we work from clear, itemized estimates so you can see what each line covers and where value engineering can protect the scope you care about. California law caps a builder’s down payment at $1,000 or 10 percent of the total contract price, whichever is less, and disciplined contract management is the practical defense against construction overruns. We will not publish a fixed price, because site conditions genuinely move the number, and we would rather be accurate than attractive.
The rest of the trust stack is simple: licensed and bonded, LIS. #1125656, a 10-year structural integrity warranty, a 1-year fit-and-finish warranty, 100+ happy customers, and 18 Google reviews. Our office is in Roseville rather than Loomis, which keeps our crews and project managers genuinely available to the Town’s job sites.
Want to see whether your lot works? Book a consultation and we will give you a site-specific read, free.
How Your Loomis ADU Project Works, Step by Step
Here is the ADU building process: five steps, one team, and a named point of contact at every handoff.
- 1. Free 1-hour walkthrough and feasibility review. This is the early planning work that decides everything after it. We walk your Loomis property and verify existing site conditions before any design begins: building envelope, setbacks, separation from existing structures, driveway access, tree locations, and drainage. We also check how utilities will reach the unit, since utility connections frequently need a thorough site evaluation, and we flag septic or well conditions immediately. You leave with an honest read on what fits and a transparent estimate range.
- 2. Design and engineering. Our architectural team develops the layout with you, collaboratively and iteratively, until the plan matches how you actually live. Structural and civil engineering are produced in-house alongside the architecture, so the drawings arrive at the Town as one coordinated set.
- 3. Permitting and agency approvals. We submit to the Town of Loomis Building Department at Town Hall, 3665 Taylor Road, and we own every correction response, keeping the plan set aligned with local laws as they are applied here. Loomis must act on a complete ministerial ADU application within 60 days when an existing single-family or multifamily dwelling is already on the lot. Worth understanding clearly: “act” includes issuing written corrections, so 60 days is a response deadline, not a promise of issuance. Where septic or a well is involved, Placer County Environmental Health review runs in parallel.
- 4. Construction and project updates. The construction process starts only after permits are approved. You get a dedicated project manager on site, clear communication, and quick responses to calls and emails. No wondering what happened this week.
- 5. Final walkthrough, handover and warranty. We carry the project through final inspection and a final walkthrough with you, then hand over a finished, occupiable ADU backed by our 10-year structural integrity warranty and 1-year fit-and-finish warranty, with construction administration available afterward.
On timing, our typical guidance is 3 to 5 months for design and permit plans and 3 to 4 months for construction. ADU projects commonly run 6 to 12 months from first design meeting to completion. Treat those as typical ranges, not guarantees: parcel conditions, agency review, and scope changes all move the schedule, and we would rather set the expectation honestly at the start.
Building an ADU in Loomis: Local Regulations, Lots and Site Conditions
Loomis sets no minimum lot-area requirement for establishing an ADU or JADU, so feasibility is decided by your building envelope, not your acreage. Small lots work more often than owners expect, and large lots occasionally fight back because of where the house, the trees, and the leach field already sit.
Here are the Loomis standards we design to, side by side, so you can measure your own property against them before we ever walk it:
| Standard | Loomis Requirement | What It Means for Your Build |
|---|---|---|
| Minimum lot size | None for an ADU or JADU | Your usable building envelope decides feasibility, not your acreage |
| Maximum detached ADU size | 1,200 sq ft (also the combined cap for two ADUs) | Studio through three-bedroom layouts all fit inside this allowance |
| Maximum JADU size | 500 sq ft, with owner-occupancy condition | The most compact option; owner must live in the house or the JADU |
| Side and rear setbacks | Generally 4 ft for ADUs up to 16 ft high | Sets how far the footprint can push toward your property lines |
| Separation from other buildings | Generally 10 ft, reducible to 6 ft with no Building Code health and safety concerns | Four feet of relief can be the difference between a studio and a two-bedroom |
| Height (downtown area) | 25 ft limit inside the defined downtown area | Relevant if your parcel sits in the Taylor Road and Downtown planning area |
| Parking | Generally one space per ADU, with listed exemptions including transit proximity | Often dictates where on a deep lot the unit can sit |
| Development impact fees | Not imposed on an ADU under 750 sq ft per current municipal code | Unit size can meaningfully change your total project cost |
| Rental term | Rentals under 30 consecutive calendar days prohibited | Long-term tenancy is the compliant path to rental income |
| Permit review | Town must act on a complete ministerial application within 60 days | “Act” includes written corrections, so it is a response deadline, not issuance |
Lot size and building envelope. Loomis residential zoning includes minimum parcel standards ranging from 5,000 square feet in RS-5 up to 20,000 square feet in RS-20, but those figures govern parcels, not ADU eligibility. The separate ADU ordinance has no minimum lot size. What we measure instead is the usable area left after setbacks, separation, access, easements, and existing improvements, and that measurement is what sets your realistic ADU size.
Setbacks, separation and height. Loomis generally requires four-foot side and rear setbacks for ADUs up to 16 feet high. The Town generally requires 10 feet between an attached or detached ADU and another building, reducible to six feet when there are no Building Code health and safety concerns. Inside the defined downtown area, the ADU height limit is 25 feet. Detached units top out at 1,200 square feet, and that figure is the maximum ADU size no matter how large the parcel is.
Parking and driveway access. Loomis generally requires one parking space per ADU, with listed exemptions including qualifying proximity to public transit. The Town normally requires an ADU to use the same vehicular access as the primary buildings, unless the specified Town and fire authorities approve a secondary access point. On a deep lot, that single rule often determines where the unit can sit.
Architectural compatibility near Taylor Road and downtown. The Town requires an ADU’s architectural style, exterior materials, and colors to be compatible with the primary dwelling. That requirement carries real weight along the historic core, where most Taylor Road structures between Walnut Street and Horseshoe Bar Road were rebuilt shortly after a 1915 fire. We design the exterior to the house you already own, in detail, at the drawing stage.
Septic, wells and Placer County Environmental Health. Many Loomis properties rely on an onsite wastewater system or a private well. An ADU using onsite wastewater requires a recent percolation test and approval from Placer County Environmental Health. A property served by an onsite water well requires health, safety, and capacity testing plus Placer County Environmental Health approval. Both take time, which is exactly why we investigate them during early planning rather than at submittal.
Creeks, canals, drainage and trees. Waterway and drainage screening is locally relevant: Secret Ravine, Antelope Creek, Antelope Canal, Penryn Canal, and Red Ravine Canal all appear in the environmental record for the Hidden Grove project area, north of the I-80 and Horseshoe Bar Road interchange between I-80 and Horseshoe Bar Road/Laird Street. Mature trees influence placement, foundation design, construction access, and utility routing, and we survey them before committing to a footprint.
Where your property sits in Town. Loomis planning materials recognize Taylor Road and Downtown, Sierra College Boulevard north of the railroad, the northwest I-80 area around Horseshoe Bar Road and King Road, and the southeast I-80 and Horseshoe Bar Road area as distinct planning areas. Those boundaries shape context and access, so we orient every feasibility review to where your parcel actually falls.
How Loomis differs from the ADU advice you have read online. Regional guides written for other California markets quote numbers that are not the Loomis standard: a 5,200 square foot minimum lot, a three-foot gap from property boundaries, a 60-foot front-line placement rule. Loomis sets its own figures and enforces its own local requirements. Working with an ADU builder who reads the Loomis ordinance, not a statewide summary, is what prevents costly correction cycles. Our office is in Roseville, a short run up the I-80 corridor, and we would rather spend an hour on your lot than guess from a map. Reach us at office@gsadus.com to set that up.
Frequently Asked Questions
What do ADU costs look like in Loomis, including a 1,000 square foot unit?
ADU costs vary by size, site conditions, utility distance, sewer versus septic, finishes, and site access, which is why we provide a transparent, itemized estimate after the walkthrough instead of publishing a price. Construction costs differ widely between a garage conversion and a new detached build of the same square footage. We use value engineering to protect the elements that matter most to you, and clear contract management to keep the budget from drifting. California law caps a builder’s down payment at $1,000 or 10 percent of the total contract price, whichever is less.
What is the most cost-effective way to add an ADU in Loomis?
Converting existing structure is usually the most cost-effective route, whether that is a garage conversion or an internal ADU inside your current footprint. You start with a foundation and shell already in place, which removes significant construction cost from the build. Size matters too: Loomis imposes no development impact fee on an ADU smaller than 750 square feet under its current municipal code. A JADU, capped at 500 square feet, is the most compact option of all.
How long does Loomis take to approve ADU plans?
The Town must act on a complete ministerial ADU application within 60 days when a dwelling already exists on the lot. Read “act” carefully: issuing written corrections counts, so a 60-day response is not the same as a 60-day permit. Our typical guidance is 3 to 5 months for design and permitting and 3 to 4 months for construction, with most projects landing somewhere in the 6 to 12 month range overall. Permitting has to be complete before construction starts, and we treat the correction cycle as our work, not yours.
Can I build an ADU if my Loomis property has a septic system or a well?
Yes, with added approvals. An ADU using onsite wastewater requires a recent percolation test and approval from Placer County Environmental Health. A property served by an onsite well requires health, safety, and capacity testing plus Placer County Environmental Health approval. We fold both into the feasibility stage, alongside a full review of how water, sewer, power, and gas will actually reach the unit, so nothing surprises you after you have paid for drawings.
Can I rent my Loomis ADU short term?
No. Loomis prohibits renting an ADU or JADU for fewer than 30 consecutive calendar days, which makes long-term tenancy the compliant path to rental income. We design accordingly, with finishes and layouts built for sustained occupancy rather than weekend turnover. Confirm current rules with the Town’s planning staff for your specific parcel before you make financial plans around them.
Do you serve Loomis, and where in the Sacramento, CA area are you based?
Yes. We are based at 1001 Enterprise Way #100 in Roseville, and we serve Loomis along with Rocklin, Penryn, Newcastle, Granite Bay, Auburn, Lincoln, and the wider area. Building accessory dwelling units is our only business, and we provide design, permitting, and construction for them throughout California. Homeowners searching for an ADU builder near me in Loomis will find plenty of general construction firms; Sacramento ADU builders who do this work exclusively are a shorter list. We also keep the Town of Loomis business license requirement in view on every project, since the Town states a building permit cannot be processed without one.
Straight answers to what Loomis homeowners ask us most. For anything parcel-specific, confirm current rules with Town of Loomis planning staff or the Town and Placer County official websites.
Start Your Loomis ADU With a Free Walkthrough
One hour on your property tells you more than a month of research. During the free walkthrough we evaluate your building envelope, setbacks, separation from existing structures, driveway access, utility routing, and septic or well conditions, then give you a transparent estimate range based on what we actually saw. You will also get a straight answer about whether building an ADU is the right move for your lot, including when it is not.
Ask to see completed units while you are at it. Looking at our finished ADUs is the fastest way to judge whether our design sensibility and top notch finish work match what you want in your own backyard.
Design, engineering, permitting, and construction stay with one team, from concept to completion, in a streamlined building process backed by a 10-year structural integrity warranty and a 1-year fit-and-finish warranty.
Call us at (916) 909-2387, email office@gsadus.com, or book a consultation online. We are at 1001 Enterprise Way #100 in Roseville, a short drive down the I-80 corridor from Loomis, and we would be glad to come see your property.
