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 Riverside Homeowners
Adding square footage to a Riverside home means navigating city setback rules, lot coverage limits, and the Inland Empire’s summer heat when planning rooflines and window placement. We’re Lodgewick ADU Riverside, the ADU company of the Kingswell family, and we’ve been building additions, garage conversions, and accessory dwelling units across this region since 2010. Russ Delmar leads our Riverside team, and every project we take runs on The Kingswell Guarantee: a written price before work begins, a defined arrival window, a clean job site, and a written guarantee on every job. If you’re sizing up a home addition in Riverside, call (831) 292-4191 and we’ll walk you through what’s realistic for your lot.
Sunroom Addition
A sunroom addition gives Riverside homeowners a bright, enclosed living space that bridges the indoors and the backyard without the full cost of a traditional room addition. These builds typically run $30,000 to $75,000 depending on square footage, glazing choices, and whether you want heating and cooling tied into the existing HVAC. Lodgewick ADU Riverside handles the full scope: slab or raised foundation, framing, glazing, roofing, and finish work, all under a written price so the number doesn’t move once we start.
Design and Glazing Choices
Riverside summers push temperatures past 100 degrees regularly, so glass selection matters more here than in coastal markets. We steer clients toward low-E glazing and operable window configurations that let the room breathe in the morning and hold cooler air in the afternoon. The Kingswell Guarantee covers the build itself, including the thermal performance of the glass package we specify.
Foundation and Site Prep
Every sunroom starts with a proper foundation, and in Riverside’s expansive soils that means soil testing and a slab or pier design that won’t shift with the seasons. We pull permits with the City of Riverside, schedule inspections, and don’t cut corners on grading or drainage. A sunroom that’s built on a bad pad becomes a problem room fast, and we’d rather do it right the first time.
Room Addition Contractor
A room addition contractor handles the design, permitting, and construction of new living space attached to your existing Riverside home, whether it’s a family room, office, or den. In this market, ground-floor room additions typically land between $180 and $340 per square foot, so a 400-square-foot addition generally runs $72,000 to $136,000 depending on foundation work, roofing ties, and interior finishes. Lodgewick ADU Riverside gives you a written, line-item price before any work starts, which means you’ll know your exact number on day one.
Permitting and Lot Constraints
Riverside has specific setback requirements, lot coverage percentages, and height limits that vary by zone, and we handle every part of the permit process in-house. Some lots in the Wood Streets or Magnolia Center have older utility easements that require extra engineering, which we identify during the initial site walk. Russ Delmar reviews every plan before it goes to the city, because a permit rejection costs you time and a resubmission costs you money.
Foundation and Structural Integration
Tying a new room into an existing Riverside home means matching rooflines, closing in exterior walls, and sometimes upgrading the electrical panel to carry the new load. We’ve done this work in neighborhoods across the city, from Arlington to Mission Grove, and we document every structural connection with photos before drywall goes up. Our 365-Day Done Right Promise means if something isn’t right, we come back and make it right, in writing.
Second Story Addition Contractor
A second story addition contractor builds upward instead of outward, adding bedrooms, bathrooms, or a bonus space above an existing single-story Riverside home. Second-story work runs higher per square foot than ground-floor additions due to structural reinforcement, stairwell construction, and roof removal, typically landing between $250 and $450 per square foot depending on access and existing framing strength. Lodgewick ADU Riverside assesses your foundation and first-floor walls before pricing anything, because a second story adds real structural load.
Structural Assessment First
Before we quote a second-story addition, we check the existing footings, the wall framing, and the condition of the sill plates where the new floor system will land. Older Riverside homes, especially those built before the 1970s, often need shear wall upgrades or foundation retrofits to carry the added weight. We tell you what’s needed, what it costs, and what’s optional, all in writing.
Roof Tying and Weather Protection
Cutting open a Riverside roof and keeping the house dry during construction takes careful sequencing and temporary weather protection, especially during the winter rain months. We stage the work in sections and get the new second-story deck sealed and dried in before removing more of the old roof than we need to. Our crews show up in the window we give you, and they leave the site clean at the end of every day.
Garage Addition Contractors
Garage addition contractors add new vehicle or storage space alongside an existing garage, or convert and expand existing garage space into a larger structure serving both cars and living needs. A detached garage addition in Riverside typically runs $45,000 to $95,000 for a two-car structure with basic electrical, while an attached garage expansion usually falls between $35,000 and $70,000 depending on roof integration and driveway work. Lodgewick ADU Riverside handles the slab, framing, electrical rough-in, and matching exterior finishes.
Slab and Drainage Requirements
A garage slab in Riverside has to hold vehicle weight and handle heat expansion without cracking, and that means proper subgrade prep and rebar layout. We also grade the surrounding soil so monsoon-season rain doesn’t pool against the stem wall, which is a common failure point we see in older neighborhoods like Casa Blanca. The written guarantee covers slab work, and if anything shifts or cracks within the year, we’re back to make it right.
Electrical and Workshop Readiness
If you want the garage to double as a shop, we’ll spec the electrical panel for the extra load: compressor circuits, 240-volt outlets, lighting arrays, and charging stations. We rough in the conduit before walls close, so you’re not paying for retrofit work later. Every plan gets reviewed by Russ Delmar before the crew starts, and the price doesn’t change at the door.
Bathroom Addition Contractor
A bathroom addition contractor builds a new full bath, half bath, or primary suite bath where none existed, often taking space from a closet, hallway, or expanding into the roofline. In Riverside, a new bathroom addition typically runs $25,000 to $60,000 depending on plumbing distance from existing drain lines, ventilation needs, and finish choices like tile and fixtures. Lodgewick ADU Riverside handles everything from drain tie-ins to waterproofing to the final trim.
Plumbing and Ventilation
Adding a bathroom means cutting into floors and walls to run supply lines and drain pipes, and in Riverside’s older slab-on-grade homes, that often means trenching through concrete. We locate the nearest existing drain stack and design the shortest viable route before tearing anything open, which keeps costs predictable. Proper exhaust ventilation is non-negotiable in Riverside’s dry but occasionally humid winters, because a bathroom that can’t move moisture will grow mold.
Waterproofing and Finish Work
The waterproofing behind tile is where cheap bathroom additions fail, and it’s also what you can’t see once the job’s done. We use full waterproof membrane systems behind shower enclosures, not just cement board and hope. The 365-Day Done Right Promise means that if a leak shows up within the guarantee period, we’re back on our dime to open it up and fix it.
Bedroom Addition Contractor
A bedroom addition contractor adds a new sleeping room to your Riverside home, whether it’s a ground-floor suite for aging parents or an upstairs bedroom for a growing family. Bedroom additions in this market typically run $150 to $300 per square foot, so a standard 12-by-14-foot bedroom usually lands between $25,000 and $50,000 depending on closet design, window sizing, and heating or cooling extensions. Lodgewick ADU Riverside builds bedrooms that meet all California Building Code requirements for egress, light, and ventilation.
Egress and Code Compliance
Every bedroom in California has to have an operable window or door large enough for emergency escape, and we don’t skip this step to save a few hundred dollars. We also confirm ceiling height minimums, required closet or storage dimensions if you’re listing the space as a bedroom later, and smoke and carbon monoxide detector placement. The city inspector signs off on all of it, and so do we.
Comfort and HVAC Integration
Riverside bedrooms need real climate control, not a window unit that fights 105-degree August afternoons. We extend your existing ductwork where feasible, or size a ductless mini-split if a duct extension would run through too much conditioned space. We’ll show you both options with real numbers, and the written price covers whichever route you choose.
Brands We Service
We work with James Hardie siding products on a regular basis across Riverside, including their fiber cement plank and panel lines that hold up especially well to the Inland Empire’s sun exposure. Our crews have completed Hardie installations on second-story additions and garage expansions, and we know the rain-screen and flashing details Hardie requires for their warranty to stay valid.
For homeowners exploring prefab ADU manufacturers, we’re familiar with Abodu, Cover, and Dvele units and can manage site prep, utility connections, and finish work around their installation schedules. Whether you have a specific brand in mind or you’re still weighing options, we can help you match the right product to your lot, budget, and timeline.
Signs You Need a Pro Right Now
- Ceiling cracks spreading from an exterior wall. If you’re seeing diagonal cracks at wall-to-ceiling intersections, especially after the rainy season, your foundation may be moving. That’s a structural issue that needs assessment before any addition gets priced.
- Electrical panel maxed out with no room for new circuits. A home addition means new outlets, lighting, and often a dedicated HVAC feed. If your panel is already full, the electrical upgrade has to happen first, and it changes the project scope.
- Roof sag visible from the street. A sagging roofline over an existing room or garage means compromised rafters or trusses. Adding square footage to a house with a failing roof structure creates dangerous load conditions that no amount of finish work can hide.
- Doors sticking or floors sloping. Sloping floors and doors that won’t latch are signs of settlement or expansive soil movement, which Riverside sees in pockets throughout the city. Before we price an addition, we need to know what’s happening underneath.
- Water staining on ceiling or wall corners. Existing leaks mean existing wood rot, and new framing tied into rotten members fails fast. We’d rather find the water source now than open walls mid-project and hand you a change order, which is exactly the situation our written pricing approach prevents.
Our Process, Step by Step
- 1
Free on-site walkthrough. We come out to your Riverside property, walk the lot, measure what’s there, and listen to what you’re trying to accomplish. No charge, no pressure, and you’ll get our honest read on whether the project fits your lot and budget.
- 2
Written scope and line-item price. Within days of the walkthrough, we deliver a written proposal that breaks down every line: demo, foundation, framing, roofing, electrical, plumbing, drywall, paint, and contingency. The number on that page is the number, and it doesn’t change at the door.
- 3
Permitting and engineering. We handle the City of Riverside permit package, including structural calcs where the addition ties into existing framing or adds a second story. We schedule inspections and handle corrections directly with the city.
- 4
Construction with a defined window. Our crews show up in the arrival window we give you, work clean, and communicate through every phase. We take photos as we build so you can see the work that gets covered up behind drywall before it disappears.
- 5
Final walkthrough and written guarantee. Before we call it done, you walk the entire addition with Russ Delmar or your project lead. If anything isn’t right, we fix it then. Then you get the 365-Day Done Right Promise in writing, covering the work for a full year, with a free return visit if anything fails.
How Much Does Home Addition Contractor Cost in Riverside?
What moves the price: foundation conditions on your specific lot, whether the existing electrical panel needs an upgrade, how far new plumbing lines have to run, and what finish level you pick for flooring, tile, and fixtures. Riverside’s permit fees and plan check costs also factor in, and we include those as actual line items, not vague estimates. The best way to avoid overpaying is to get a written, line-item price up front, which is exactly what we provide. Our free estimates include a full scope review, so when you call (831) 292-4191 you’ll get a real number you can plan around, not a guess.
Our Service Area Near Riverside
Lodgewick ADU Riverside builds home additions throughout the city and across the surrounding Inland Empire, including Ontario, Fontana, Chino, Rialto, Upland, Montclair, Highland, Beaumont, Wildomar, Temescal Valley, and El Cerrito. If you’re weighing a Home Addition Contractor in Ontario or exploring options in Home Addition Contractor in Fontana, the same written pricing and guarantee apply. Most projects within a 30-mile radius of Riverside see our crews on site within two weeks of permit approval. For homeowners comparing additions to garage conversions or standalone ADUs, take a look at our home page to see how the different approaches compare.
Serving Riverside, CA - Our Local Coverage Area
We’re a Home Addition Contractor - Riverside team that knows 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 Riverside
What is a home addition contractor?
A home addition contractor is a licensed building professional who designs, permits, and constructs new attached living space on your existing home, such as a bedroom, bathroom, sunroom, or second story. Lodgewick ADU Riverside handles the full scope from initial site assessment through final inspection. We give you a written price before work starts, and every project carries the 365-Day Done Right Promise in writing.
How long does a home addition take in Riverside?
A ground-floor room addition typically takes 8 to 12 weeks from permit issuance to final walkthrough, while a second-story addition usually runs 4 to 6 months depending on structural work and weather. Bathroom additions can be done in 4 to 6 weeks, and sunrooms in 6 to 10 weeks. Your timeline gets spelled out in the written proposal, and we don’t leave a job site for weeks at a time without telling you why.
How much does a home addition cost in Riverside?
Ground-floor additions run $180 to $340 per square foot, second stories $250 to $450 per square foot, and bathrooms $25,000 to $60,000 as a standalone project. Sunrooms land between $30,000 and $75,000, and garage additions between $35,000 and $95,000 depending on size and electrical finish. Call (831) 292-4191 for an exact, written quote for your specific scope, because every lot and house is different.
Do you work with James Hardie products on additions?
Yes, we install James Hardie fiber cement siding and trim on home additions across Riverside, and we follow Hardie’s required flashing and rain-screen details so their product warranty stays valid. Our crews have completed Hardie installations on second-story and garage expansion projects. If you prefer a different cladding, we’ll price it honestly either way.
Do you offer emergency structural work before an addition starts?
If our walkthrough uncovers a structural issue like a failing foundation or roof sag, we’ll put a plan in writing to address it before the addition work begins. We don’t leave you hanging with a problem we found. Our office answers calls around the clock, and when you call (831) 292-4191, a live person picks up.
What does the 365-Day Done Right Promise cover?
The 365-Day Done Right Promise covers the workmanship on your entire addition for one full year from the date of completion. If anything we built fails or isn’t done right, we come back and fix it at no charge to you. That promise is in writing before we start, not after you pay.
How do I prepare for a home addition project?
Start by making a list of what you need the new space to do, not just how big you want it, because function drives layout. Gather your property’s parcel number and any previous survey documents if you have them. Then call (831) 292-4191 to schedule your free walkthrough, and we’ll handle the measurements, the permit research, and the written price from there.
Schedule Your Home Addition Contractor Service in Riverside Today
Ready to get a real number for your Riverside home addition? Call Lodgewick ADU Riverside at (831) 292-4191 and schedule your free, no-obligation estimate. You’ll get a written, line-item price before any work starts, a defined arrival window, and the 365-Day Done Right Promise on every project. Talk to Russ Delmar and the team directly, any time, any day.
Written by Russ Delmar, Owner at Lodgewick ADU Riverside, serving Riverside since 2010. See our Home Addition Contractor Maintenance Checklist for Riverside Homeowners.
