







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateTrusted Home Addition Contractor for Sacramento Homeowners
Adding square footage to a Sacramento home is a decision that carries weight: it changes how you live, what your property is worth, and who you let through your front door for months at a time. Sutton ADU Sacramento, your Home Addition Contractor - Sacramento, was built for that exact moment. Founded in 2006 and led by Miles Hartwell, our team is the ADU-specialist member of the Threshold Group family, and we operate under one simple rule: you get a written price before any tool is lifted, and you know exactly who is walking onto your property before they arrive.
That last part matters more than most contractors admit. Sacramento homeowners often tell us the same thing: they put off a room addition not because of cost, but because they didn’t want strangers in the house for weeks with no way to verify who they were. Our answer is the Threshold Verified standard. Every technician is background-checked, identity-verified, uniformed, and photo-badged. Their name and photo are sent to you before the visit. When the doorbell rings, you check the badge against the photo you already have. That’s the standard on every project, whether it’s a home addition in Sacramento or a full detached ADU. Call (279) 300-1690 and you’ll get a live person, not a voicemail tree.
Sunroom Addition

Sunroom Addition work in Sacramento means building a conditioned, glass-forward living space that connects your indoor rooms to the backyard light without framing a full conventional addition. Homeowners choose this route when they want usable square footage fast, want to keep foundation work minimal, or simply love the idea of a bright room that feels like the garden without the mosquitos. In Sacramento’s climate, a properly built sunroom with insulated glass and a dedicated mini-split can serve as a reading room, a plant room, or a home office nearly year-round. We handle the design, permits, slab or deck foundation, glazing, and electrical. A modest sunroom addition in Sacramento typically runs $45,000 to $90,000 depending on glazing grade and whether you need a new slab or can build over an existing patio.
Glazing choices that actually hold up
Sacramento summers punish cheap glass. We specify low-E insulated units with argon fill for west-facing sunrooms, because the difference between standard dual-pane and low-E in an August afternoon is a room you can sit in versus a greenhouse. For east-facing rooms we still recommend low-E, but the frame choice matters more than the coating.
Foundation and floor planning
An existing concrete patio can sometimes carry a sunroom, but only if we verify the slab thickness and subgrade first. In older Sacramento neighborhoods like Land Park or East Sacramento, we often find 3-inch patio pours that were never meant to hold walls. We’ll tell you plainly whether you need a new perimeter footing or a full slab, and that number goes into the written price before we start, not after.
Second Story Addition Contractor
Second Story Addition Contractor work is what Sutton ADU Sacramento does when a lot has no room to expand outward but the household has outgrown the first floor. A second story addition is the most structurally involved type of home addition: it requires evaluating the existing foundation, opening load-bearing walls, adding new shear capacity, and often upgrading the electrical service. Sacramento homes built between the 1940s and 1970s, common in neighborhoods like Tahoe Park and Colonial Heights, were rarely framed with a future second story in mind. We begin every second-story estimate with a structural walkthrough, and we’re honest when the cost of reinforcing an older foundation makes a detached home addition a better financial move. A second story addition in Sacramento generally runs $250,000 to $450,000 depending on square footage, roofline complexity, and whether you need a new stairwell carved out of existing living space.
When the foundation says no
In parts of Sacramento with expansive clay soil, like portions of Rosemont, Florin, or our Home Addition Contractor in Rancho Cordova service area, an existing foundation can move enough over decades that adding a second story becomes a seismic and settlement risk. We review soil reports and slab performance history before quoting, and if reinforcing is required, that cost is line-itemed. We’d rather lose a bid than pour a second story onto a foundation we don’t trust.
Living through the build
A second story addition means you stay in the home while the roof comes off and the framing goes up. We stage the work in phases that keep the first floor sealed and livable, and we tell you exactly which weeks require utility shutoffs. The crew you’ll see during those weeks is the same Threshold Verified crew from day one: background-checked, photo-badged, and accountable to the same written price.
Garage Addition Contractors

Home Addition Contractor in Rio Linda and Sacramento-area garage specialists build attached or detached garages that do more than park cars: they become workshops, storage headquarters, or a first step toward a future ADU conversion. A garage addition makes sense when your existing carport is falling apart, when you need locked storage for tools or inventory, or when you want a clean, insulated shell you can convert to living space later under Sacramento’s ADU rules. We build stick-framed garages with proper footings, code-compliant electrical, and a roof system that can carry solar later if you want it. A detached two-car garage addition in Sacramento typically runs $60,000 to $110,000. An attached garage with a breezeway runs slightly less per square foot but adds roof tie-in complexity.
Prepping for a future ADU conversion
More Sacramento homeowners are building garages with a second act in mind. If you think you may convert the garage to an ADU in five or ten years, we’ll size the footings, slab, and rough plumbing stubs for it now. The upfront cost is modest, usually $4,000 to $8,000, and it saves you from cutting a finished slab later. This is exactly the kind of advice you get when your contractor has built real ADUs, not just read about them.
Detached vs. attached: what changes
An attached garage adds convenience but triggers more siding, roofline, and fire-separation requirements at the shared wall. A detached garage keeps construction noise out of the house and gives you a simpler permit path in most Sacramento County jurisdictions. We’ll lay both options out in the written estimate so you can decide with real numbers, not a sales pitch.
Bathroom Addition Contractor
Bathroom Addition Contractor work is for Sacramento homeowners who are tired of one bathroom for four people. Adding a bathroom changes the daily rhythm of a household more than almost any other addition: no more morning queues, no more guests walking through the master bedroom to wash their hands. We build full bathrooms and half-baths in Sacramento homes, handling the supply and drain plumbing, venting, waterproofing, tile, and fixture installation under one written price. A half-bath addition in Sacramento typically runs $25,000 to $45,000. A full three-piece bathroom runs $45,000 to $80,000, and a primary-suite bathroom with a walk-in shower can reach $90,000 to $130,000 depending on finishes.
Where the new plumbing goes
Adding a bathroom often means running new drain lines across an existing slab or through floor joists. In older Sacramento pier-and-beam homes, like many in Oak Park and Curtis Park, the access is usually straightforward. On slab-on-grade construction, we may need to cut and trench the slab, which adds cost and dust. We walk you through exactly where the waste line will run before we quote, because “we’ll figure it out during demo” is how change orders are born.
Waterproofing is the warranty’s best friend
Bathroom additions fail long-term when the waterproofing is rushed. Our 365-Day Done Right Promise covers defects in workmanship for one full calendar year from project completion, but a bathroom built with proper Schluter or equivalent waterproofing systems should look the same at year ten as it does at day one. We use full waterproofing membranes, not just green board and hope.
Bedroom Addition Contractor

Bedroom Addition Contractor work in Sacramento solves a specific problem: the household grew, and the floor plan didn’t. Maybe it’s a second child, an aging parent moving in, or a home office that needs to become a real bedroom. A bedroom addition requires egress windows, closet provisions, proper heating and cooling, and in California, smoke and carbon monoxide detection tied to the existing system where code requires. We handle all of it under one contract. A single bedroom addition in Sacramento typically runs $80,000 to $150,000, with the range driven by whether we’re extending a roofline, pouring a new foundation wing, or converting an existing enclosed space like a porch or bonus room.
Egress and code compliance
Any room we call a bedroom must have a code-compliant emergency escape window, minimum square footage, and proper ventilation. We handle the measurements and the permit drawings, and we’ll flag it early if your existing windows won’t meet egress and need to be enlarged. That’s the kind of detail that routinely gets missed by handyman crews, and it matters for both safety and resale.
HVAC for the new square footage
A bedroom addition that’s just tapped off the existing ductwork often ends up hot in summer and cold in winter. We perform a quick load calculation during the estimate and recommend either a dedicated ductless mini-split or a ducted zone with proper balancing. The mini-split route typically adds $4,000 to $7,000 and solves the comfort problem permanently. It’s optional, but we’ll tell you honestly if we think you’ll regret skipping it.
Brands We Service
We have hands-on experience with the leading ADU and prefab product lines, starting with Abodu. Abodu’s turnkey detached ADU model is popular with Sacramento homeowners who want a predictable timeline and a fixed price from a factory. We handle the site preparation, foundation, utility connections, and finishing work for Abodu units, and we know their installation envelope well enough to spot site issues before the unit arrives. When the unit shows up, it goes in right the first time.
Cover and Dvele take a different approach: Cover builds custom panelized units that fit oddly-shaped Sacramento lots, and Dvele builds high-performance modular homes with an emphasis on indoor air quality and energy performance. We’ve worked with both systems and can give you an honest comparison of cost, timeline, and what each one does well. If your project calls for James Hardie fiber cement siding, we’re experienced with their full cladding system, which matters in Sacramento’s dry heat and occasional hard rains. Whether you have an Abodu, Cover, Dvele, or any other make, we can help you get it placed, connected, and finished.
Signs You Need a Pro Right Now
- Your roofline is sagging or the ceiling shows a new crack. A sagging ridge or a ceiling crack that appeared within a few months can mean foundation movement or an undersized beam. In Sacramento’s clay-heavy soil, this is worth a structural look before it becomes a six-figure problem.
- Your electrical panel is already maxed out. If your panel is full and you’re planning an addition, you’ll likely need a service upgrade from 100 to 200 amps. Running new circuits on an overloaded panel is a code violation and a fire risk. We check panel capacity during every estimate.
- You’ve been turned down for a permit by another contractor. Some Sacramento additions get quoted cheap because the contractor never intended to pull permits. If you’ve been told “you don’t need a permit for this,” get a second opinion. Unpermitted additions become a liability at resale and can be red-tagged.
- Your foundation shows stair-step cracks in the brick or stucco. These can indicate differential settlement, especially in older Sacramento neighborhoods with expansive soils. Adding a new structure to a moving foundation makes the problem worse. We’ll bring in a soils or structural engineer when the signs warrant it.
- Your existing space floods or sweats in Sacramento’s wet season. A room addition built without proper drainage or vapor barrier will show moisture damage within a year or two. If you see efflorescence on the slab or damp drywall near the floor, call before you build on top of the same mistake. Call (279) 300-1690.
Our Process, Step by Step
- 1
The walkthrough and written estimate. Miles Hartwell or a senior project lead walks your Sacramento property, measures, checks access, looks at the panel, the foundation, and the roofline, and asks how you actually live. Within a few days you receive a written, line-itemed price that covers the scope we discussed. No allowances, no “to be determined” line items.
- 2
Permit drawings and submittal. We prepare the drawings or work with our drafting partners, then submit to the City of Sacramento or Sacramento County. We handle the plan-check comments and revisions. You’ll know the permit status at every stage because you’ll have a direct line to our project coordinator.
- 3
Threshold Verified crew on site. Before any work begins, you receive the name and photo of every technician assigned to your project. They arrive in clean, marked uniforms and show photo ID at the door. Every single one has been background-checked and identity-verified. This is the Threshold Standard, and it applies to every trade on your property.
- 4
The build, with weekly check-ins. We run the project on a schedule you can see, with a weekly call or text update covering what happened, what’s next, and any decisions we need from you. If a question comes up mid-week, you call us and a live person answers. No project manager voicemail tag.
- 5
Final walkthrough and the 365-Day Done Right Promise. Before we call the job complete, we walk every room with you and build a punch list. When the list is cleared, your 365-Day Done Right Promise goes into effect in writing. If anything isn’t right within one full calendar year, we make it right. And if a repair or element fails, the second visit is on us. No haggling, no fee.
How Much Does Home Addition Contractor Cost in Sacramento?
Home addition costs in Sacramento follow a fairly predictable range once you understand what drives them. A bathroom addition runs $25,000 to $80,000. A bedroom addition runs $80,000 to $150,000. A sunroom runs $45,000 to $90,000. A garage addition runs $60,000 to $110,000. A second story addition runs $250,000 to $450,000. And most detached ADUs in the 400 to 800 square foot range run $180,000 to $320,000 before site work like trenching, tree removal, or major grading.
What moves the price: foundation conditions, access to the build area, the age of your existing structure, and permit requirements in your specific Sacramento jurisdiction. A home addition contractor in Sacramento cannot responsibly give you a real number without seeing the site, because the difference between a simple slab pour and a foundation that needs engineered reinforcement can be $15,000 or more. The way to avoid overpaying is to get a written, line-itemed estimate that separates labor, materials, permits, and site work. If a contractor won’t break it out, the number is negotiable in their favor. Our free estimates include the full line-item breakdown, and the price we show you is the price you pay unless you change the scope. Call (279) 300-1690 to set one up.
Our Service Area Near Sacramento
Sutton ADU Sacramento serves homeowners throughout the greater Sacramento region, including Elk Grove, Rancho Cordova, Rocklin, Lincoln, Arden-Arcade, Orangevale, Florin, Rosemont, Loomis, Rio Linda, and Wilton. Most of our Sacramento metro projects are within a 30-minute drive of our base, which means estimate visits can usually be scheduled within the week. For larger additions and ADUs, we plan site work around your availability and the permit timeline, not around our convenience.
Serving Sacramento, CA - Our Local Coverage Area
We’re based in the Sacramento area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions About Home Addition Contractor in Sacramento
A home addition contractor is a licensed general contractor who specializes in adding new conditioned square footage to an existing home, including bedrooms, bathrooms, sunrooms, garages, and second stories. In Sacramento, this contractor handles design coordination, permits, structural work, electrical, plumbing, HVAC, and finishes under one contract. Sutton ADU Sacramento fills this role with a written price before work begins and the Threshold Verified crew standard. Call (279) 300-1690 for a free estimate.
Most single-room additions in Sacramento take 8 to 16 weeks from permit approval to final walkthrough, depending on scope and weather. A second story addition typically runs 5 to 8 months. Your timeline depends heavily on City of Sacramento or County plan-check turnaround, which can add 4 to 10 weeks before construction starts. We’ll give you a realistic schedule at the estimate, and we’ll update it weekly during the build. Call (279) 300-1690 to discuss your project’s likely timeline.
A home addition in Sacramento typically costs between $25,000 for a small half-bath and $450,000 for a full second story, with most single-room additions landing in the $80,000 to $150,000 range. Detached ADUs run $180,000 to $320,000 before site work. The exact cost depends on foundation conditions, access, finishes, and your local jurisdiction’s permit fees. Every Sutton ADU Sacramento estimate is free, written, and line-itemed. Call (279) 300-1690 for an exact quote.
Yes, Sutton ADU Sacramento has direct experience with Abodu, Cover, and Dvele ADU product lines, plus James Hardie cladding systems. We handle site prep, foundation, utility connections, and finishing work for these units, and we can advise you on which product fits your Sacramento lot and budget. If you already own one and need installation or repair support, we can help. Call (279) 300-1690 to discuss your specific unit.
For genuinely urgent issues like a failed foundation wall or a roof that’s unsafe, we can prioritize an assessment visit. However, home additions are planned construction projects, not emergency repairs; we don’t promise same-day starts on new builds. What we do promise is a written price and a real schedule once we’ve seen the site. If you have a time-sensitive concern about an existing structure, call (279) 300-1690 and a live person will help you figure out next steps.
Our 365-Day Done Right Promise covers defects in workmanship for one full calendar year from project completion. If an element of the build fails due to our workmanship within that year, we return and repair it, and the second visit is free. No haggling, no fee, no fine print. The promise is written and stamped on every project. Call (279) 300-1690 if you have questions about coverage on a current or past project.
Gather any existing plans or surveys of your property, make a list of what you want the new space to do, and clear a path to the areas we’ll need to inspect, including the electrical panel and crawlspace if accessible. You don’t need to clean or stage anything. We’ll handle measurements, photos, and the questions that help us give you a real written price. Call (279) 300-1690 to schedule your free walkthrough.
Schedule Your Home Addition Contractor Service in Sacramento Today
You deserve a price you can plan around and a crew you can verify at the door. That’s what Sutton ADU Sacramento delivers on every project, from a half-bath to a full second story. Call (279) 300-1690 to schedule your free estimate. A live person answers, we’ll walk your property, and you’ll get a written, line-itemed price before any tool is lifted.
Written by Miles Hartwell, Owner at Sutton ADU Sacramento, serving Sacramento since 2006.



