A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateTrusted Room Addition Contractor for Fresno Homeowners
Adding a room in Fresno means dealing with two realities most contractors won’t mention out loud: summer heat that punishes sloppy framing, and a permit process that rewards builders who’ve done it a hundred times. We’re Benson ADU Fresno, led by Troy Eastman, and we’ve been building room additions and ADUs since 2006 as part of the Relay Home Co. family. Our pricing approach is simple: you get a written price before any work starts, background-checked uniformed technicians on site, and a 365-Day Done Right Promise in writing on every project. If you’re researching what a room addition should cost in Fresno, call (559) 206-2363 and we’ll walk you through real numbers for your specific lot and square footage.
Sunroom Builders
Sunroom Builders specialize in glass-heavy, slab-on-grade additions that bring daylight in without the full HVAC and insulation scope of a traditional room. In Fresno’s climate, a poorly designed sunroom becomes a greenhouse by June, so the glazing spec, roof overhang, and ventilation path matter more than the square footage. Benson ADU Fresno plans and builds sunrooms in the $40,000 to $90,000 range for a typical 200 to 400 square foot addition, with the final number driven by glazing type, foundation condition, and whether you want it tied into your existing HVAC or kept as a three-season space.
Glazing and Orientation First
We orient the glass wall to the north or east where possible, and we spec low-E glazing with a solar heat gain coefficient tuned for Fresno’s 100-degree afternoons. The difference between the right glass and standard builder-grade glass can be 15 to 20 degrees inside during August. We’ll show you the spec sheet before you sign, not after.
Foundation and Thermal Break
Slab-on-grade is standard for sunrooms, but without a proper thermal break at the sill plate, you’ll feel heat bleeding up through the floor. We install rigid insulation under the slab edge and isolate the frame from the concrete, which sounds technical but takes about a day and pays back every summer after.
Room Additions
Room Additions are site-built, stick-framed extensions that tie into your existing roofline, foundation, and HVAC system: a new bedroom, a family room, a home office, or a dining room bump-out. In Fresno, these projects typically run $60,000 to $180,000 depending on square footage, structural complexity, and finish level. Benson ADU Fresno, your trusted Room Addition Contractor in Fresno, handles the whole thing under one written price: foundation, framing, roofing, drywall, electrical, flooring, and paint. No subs you have to chase, no change orders appearing mid-project.
Tying Into the Existing House
The hardest part of any room addition is the transition: where the new roof meets the old roofline, where the new slab meets the existing foundation, and how the HVAC ductwork gets extended. We cut in connections that shed water properly and flash every seam, because Fresno’s winter rain events test roofline transitions harder than people expect. We photograph every transition before it gets covered.
Permit and Setback Reality
Fresno lots come with setback rules and lot-coverage limits that can kill a room addition before it starts if nobody checks first. We pull the permit, handle the plans, and verify your lot’s specific constraints before you spend a dollar on construction with our our Room Addition Contractor in Clovis team ready to assist nearby. If your addition won’t fit under the rules, we’ll tell you on the first visit, not the third.
Modular Home Addition
Modular Home Addition refers to prefabricated room modules built off-site in a controlled factory, then delivered and set on your foundation. This approach cuts on-site framing time dramatically and, in many Fresno cases, lands 10 to 15 percent under an equivalent site-built addition. Benson ADU Fresno is authorized to build with leading modular and prefab brands including Abodu and Cover, so you’re not locked into one take-it-or-leave-it product. Expect modular room additions in Fresno to run $70,000 to $200,000 depending on module size, site prep, and utility connections.
Factory Precision, Faster Timeline
Off-site construction means framing happens in a dry, temperature-controlled factory, not on a muddy Fresno lot in February. Tolerances are tighter, wasted material drops, and the on-site phase usually wraps weeks faster than stick framing. You still need the same foundation and utility work, but the time your yard is torn up shrinks meaningfully.
Site Prep and Crane Access
Modular modules arrive on a flatbed and get set with a crane, so your lot needs clear access and a foundation that’s been surveyed and built to tighter tolerances than site framing requires. We handle the site survey, foundation, and crane coordination under one written contract. You don’t have to hire a separate crane operator or wonder whose job that is.
Home Addition Plans
Home Addition Plans are the architectural drawings and engineering documents required to pull a building permit for your addition in Fresno. A complete plan set includes floor plans, elevations, foundation details, roof framing, electrical layout, and Title 24 energy calculations. Benson ADU Fresno produces or coordinates complete permit-ready plan sets for room additions and ADUs, and the design and engineering phase typically runs $8,000 to $25,000 depending on scope and structural complexity. We include the written price for plans in your total project quote, so you know the full number before committing.
Permit-Ready, Not Just Pretty
A lot of nice-looking plans die at the Fresno permit counter because they miss structural details or Title 24 compliance. Our drawings go out with every sheet the reviewer will actually check, which means fewer correction cycles and a faster approval. We’d rather spend an extra week on engineering than three extra weeks in plan review limbo.
Designing for How You’ll Actually Live
Good plans reflect how you move through the house: where the morning light lands, how furniture will actually fit, where the TV is going. We sit down with you and sketch real layouts before the formal drawings start, because changing a plan on paper costs hundreds and changing it after framing costs thousands. Bring photos, bring measurements, bring the Pinterest board.
In Law Suite Builders
In Law Suite Builders design and construct attached or detached secondary living spaces with their own entrance, kitchenette or full kitchen, bathroom, and sleeping area: a private apartment for an aging parent, an adult child, or a long-term guest. In Fresno, in-law suites range from $90,000 for a compact attached conversion up to $250,000 or more for a detached unit with a full kitchen and separate utility connections. Benson ADU Fresno, led by Troy Eastman, builds these as proper ADUs under California ADU law, which means they add real value to your property and can be legally rented.
Attached vs. Detached Trade-Offs
Attached in-law suites cost less and share walls, plumbing, and sometimes HVAC with the main house. Detached units cost more but give both households real privacy. We’ll line up both options with real numbers for your lot, so you can decide on cost and lifestyle, not guesswork.
Accessibility and Aging in Place
If the suite is for a parent or someone with mobility limitations, we spec wider doorways, a zero-threshold shower, lever handles, and grab-bar blocking from the start. Retrofitting those features later costs two to three times more. We design for the next ten years, not just move-in day.
ADU Conversion
ADU Conversion means turning existing square footage, typically a garage, basement, or underused workshop, into a legal accessory dwelling unit with its own kitchen, bath, and entrance. In Fresno, garage conversions are the most common path and typically cost $80,000 to $220,000 depending on structural upgrades, utility work, and finish level. Benson ADU Fresno handles conversions from the first site check through final inspection, and we’ve built with prefab components from brands like Dvele and Cover, which can lower costs and shorten timelines on conversion projects.
Garage Conversion Reality Check
Converting a garage starts with an honest look at the slab, the framing, and the electrical service. Fresno garages built before the mid-1980s often need foundation reinforcement and a full electrical service upgrade before finish work can start. We identify those costs in the written estimate, not after demo day.
JADU vs. Full ADU
A JADU, or junior accessory dwelling unit, is a smaller conversion, typically up to 500 square feet, that can share a bathroom with the main house. A full ADU needs its own bathroom and kitchen. JADUs cost less and permit faster, but come with occupancy and rental restrictions. We’ll help you pick the right one for your family and your property value goals.
Brands We Service
We’re authorized to build with Abodu, a prefab ADU company whose units are engineered for California seismic and energy codes. We’ve gone through their installation training and handle foundation, utility connections, and finish work on Abodu projects regularly, so you don’t have to coordinate between a factory rep and a local crew.
We also build with Cover and Dvele, two manufacturers taking different approaches to high-performance prefab construction. Cover’s panelized system allows for more custom floor plans, while Dvele focuses on full-home-level insulation and air sealing standards. Whether you have one of these brands in mind or any other make, we can help you evaluate the options against your budget and your lot.
Signs You Need a Pro Right Now
- Cracked foundation or failing slab. If the area where you want your addition sits on shifting or cracked concrete, delaying the fix means the new structure inherits the problem. We assess the slab and footings before any framing goes up, because a foundation failure after drywall is ten times more expensive to correct.
- Asbestos or lead paint in the existing structure. Homes in Fresno built before 1978 often have lead paint, and pre-1980s finishes may contain asbestos. Cutting into those materials without proper testing and containment is a health risk. We test before we cut, and the test result is part of your written estimate.
- Undersized electrical panel. A newer addition with a kitchen or mini-split HVAC pulls more amps than your 100-amp panel may be able to give. If you’re seeing flickering lights or tripped breakers already, the addition will make it worse. We inspect the service size on the first visit and include any upgrade in the written price.
- Roof leaks at the transition point. If water is getting in where an old patio cover or addition was poorly tied in before, it’s doing quiet damage behind the walls. We cut out bad transitions and rebuild them with proper flashing and a written guarantee on the repair.
- Setback and easement surprises. If your property survey shows an easement or a setback line that runs through where you want to build, that’s a project-killer if handled late. We pull the survey and check zoning before we design anything, so you don’t pay for a dream that can’t be permitted.
Our Process, Step by Step
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Phone call and ballpark. You call (559) 206-2363 and talk to a live person, not a voicemail tree. We ask about your lot, your square footage goals, and your budget range, then give you a ballpark number based on recent Fresno projects. You’ll know if this is worth a site visit before anyone drives out.
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Site visit and written estimate. Troy Eastman or one of our senior project leads walks your property, checks the foundation, panel, roof, and setback, and then sends you a written line-item estimate. Every number is fixed, not a range with an asterisk. No verbal handshake pricing, ever.
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Plans and permit. We produce or coordinate permit-ready drawings and handle the Fresno permit submittal. You’ll see the plan set before it goes in, and we track the permit through approval. If the city asks for corrections, we handle them.
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Construction with photo updates. Work starts only after you approve the written price and the permit is issued. You get real-time progress updates and photos at every major phase: foundation, framing, rough mechanical, drywall, finish. You’ll always know what happened this week.
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Walkthrough and written guarantee. We do a final walkthrough with you, note any punch-list items, and fix them before final payment. Every project carries the 365-Day Done Right Promise and a written guarantee. If a covered issue comes up within a year, we make it right, and we put it in writing so you’re not relying on a handshake.
How Much Does Room Addition Contractor Cost in Fresno?
A typical room addition in Fresno runs $60,000 to $180,000 for a site-built addition, $40,000 to $90,000 for a sunroom, and $80,000 to $250,000 for an ADU or in-law suite conversion, depending on square footage, finish level, and site conditions. A prefab or modular option from Abodu or Cover typically lands in the $70,000 to $200,000 range including foundation and utility work. Here’s a breakdown of what drives the cost:
- Square footage: More square feet means more foundation, framing, roofing, drywall, and flooring. The cost per square foot usually drops slightly as the project grows, but the total goes up.
- Kitchen and bathroom scope: Adding a wet bar or a full bath pulls in plumbing, drainage, venting, and waterproofing. That’s where ADU and in-law suite costs climb fastest.
- Electrical panel capacity: If your panel needs an upgrade from 100-amp to 200-amp service, that’s typically $3,000 to $6,000 added to the project. We check this on the first visit so it’s in the written price.
- Finish level: Builder-grade flooring, cabinets, and fixtures cost far less than custom millwork and stone. We show you three finish tiers with real prices so you decide where to spend.
- Site access and foundation conditions: A tight backyard with poor crane access or a slab that needs repair changes the math. We factor this in during the site visit, not as a surprise change order later.
How to avoid overpaying: get a written line-item price, not a verbal range. Ask what’s included and what’s not. Verify that permits and inspections are part of the contract. A free estimate from us includes a full scope breakdown and a fixed number, so you can compare it against other bids line by line. Call (559) 206-2363 if you want straight numbers on your specific project.
Our Service Area Near Fresno
Benson ADU Fresno serves homeowners throughout Fresno County and the surrounding Central Valley communities, including Room Addition Contractor in Sanger, Room Addition Contractor in Kerman, Clovis, Madera, Selma, Reedley, Kingsburg, Parlier, Hanford, Los Banos, and Coalinga. Most no-obligation site visits within 25 miles of Fresno happen within a few business days of your call. If you’re in a farther community, we’ll tell you on the phone what to expect for scheduling.
Serving Fresno, CA - Our Local Coverage Area
We’re based in the Fresno 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 Room Addition Contractor in Fresno
A room addition contractor is a licensed general contractor who plans, permits, and builds new attached square footage on your home. They handle everything from foundation to framing to roofing, electrical, plumbing, drywall, and finish work, or they coordinate the licensed subcontractors who do. Benson ADU Fresno operates as a single point of contact with one written price for the whole project, so you’re not juggling five different crews, whether you need a Sanger Room Addition Contractor or Fresno-based service.
A typical site-built room addition takes 3 to 6 months from planning and permit to final inspection, depending on scope and how quickly the city reviews your plans. Modular and prefab options from brands like Cover or Abodu can shorten the on-site construction phase by several weeks. We’ll give you a realistic timeline in writing before work starts, not an optimistic one in conversation.
Most room additions in Fresno fall between $60,000 and $180,000, with sunrooms running lower and ADU or in-law suite conversions running higher. The final number depends on square footage, whether you’re adding a bathroom or kitchen, site conditions, and finish level. Call (559) 206-2363 for an exact quote, the estimate is free and it’s in writing.
Yes, we’re authorized to build with Abodu, Cover, Dvele, and several other leading prefab and modular brands. We handle foundation, site prep, crane coordination, utility connections, and finish work for these systems under one contract. If you have a specific brand in mind, we’ll tell you honestly whether it fits your lot and budget.
Yes, a live person answers our phone 24/7 at (559) 206-2363, including weekends and holidays. If you hit a problem during construction, you’ll reach a person who can dispatch help, not an answering service that takes a message. This matters during a storm or a utility issue.
Every project carries the 365-Day Done Right Promise: if any covered work fails within a full year, we make it right. We also provide a written guarantee on every project and a free second visit if any covered repair fails. The guarantee is stamped on your project documents before work starts.
Have a rough idea of the square footage you want, the room’s purpose, and any must-have features like a bathroom or a separate entrance. If you have property survey documents or old plans, pull them out. You don’t need to clear anything or have answers to every question, that’s what the visit is for. We’ll handle the rest from the first measurement to the written estimate.
Schedule Your Room Addition Contractor Service in Fresno Today
You’ll get a written price before any work starts, a live person on the phone, and a 365-Day Done Right Promise on the finished project. No vague estimates, no disappearing contractors, no surprises at the door. Call (559) 206-2363 now to schedule your free, no-obligation estimate for a room addition, ADU, or sunroom in the Fresno area. You can also explore our home page to learn more about how we work.
Written by Troy Eastman, Owner at Benson ADU Fresno, serving Fresno and the surrounding Central Valley since 2006.
