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 San Diego Homeowners
A home addition in San Diego typically costs between $85,000 and $350,000 depending on square footage, foundation work, and finishes, and most projects take 4 to 9 months from permit to final walkthrough. We’re Lodgewick ADU San Diego, and we’ve been building additions, ADUs, and garage conversions across San Diego County since 2010 under The Kingswell Guarantee: a written price before work begins, a defined arrival window, a clean job site, and a written guarantee on every project. If you’ve had a contractor change the price at the door or disappear after the deposit, that ends here. Russ Delmar leads our San Diego team, and every job gets a written commitment before a single nail is driven. Call (619) 376-2760 to talk through your project and get a real number in writing.
Sunroom Addition
A sunroom addition is a glass-enclosed living space attached to your home that brings in natural light without the full cost of a traditional room addition. Homeowners in Clairemont, Tierrasanta, and Scripps Ranch often choose sunrooms when they want a bright reading nook, a plant room, or a casual dining area that feels connected to the yard. At Lodgewick ADU San Diego, a sunroom addition typically runs $45,000 to $110,000 depending on glazing type, foundation requirements, and whether you want climate control. We use James Hardie siding and low-E glass packages suited to San Diego’s coastal sun and inland heat, and every sunroom gets The Kingswell Guarantee in writing before the first permit is pulled-just as outlined in our Home Addition Contractor Maintenance Checklist for San Diego Homeowners.
Foundation and Glazing Choices
Most San Diego sunrooms go on a slab-on-grade foundation, though second-story sunrooms are possible in some neighborhoods. The glazing package is the single biggest cost driver: single-pane is cheaper up front, but dual-pane low-E keeps the room usable in August and January. Russ Delmar’s team will show you line-item pricing for both options before you commit.
Permitting and Timeline
Sunrooms under 120 square feet sometimes qualify for lighter permit requirements in San Diego, but most attached sunrooms still need full city review. Expect 10 to 16 weeks from permit submission to final inspection for a typical sunroom. We pull the permits, schedule inspections, and handle every step so you don’t chase paperwork.
Room Addition Contractor
A Home Addition Contractor in San Diego builds new living space attached to your existing home, whether that’s a family room, home office, or expanded kitchen. In San Diego’s older neighborhoods like Normal Heights, University Heights, and Kensington, homes built in the 1920s through 1950s often lack the open floor plans buyers want today. Lodgewick ADU San Diego handles the full build as your single point of contact, and a standard room addition here runs $85,000 to $180,000 depending on square footage, kitchen or bath involvement, and structural upgrades required by the existing framing. Every project starts with a written price, so you know the number before any work begins.
Structural Considerations
Older San Diego homes often have 2×4 framing, knob-and-tube wiring remnants, and foundations that need attention before an addition ties in properly. We inspect the existing structure during the estimate and include any seismic retrofit or load-path corrections in your written price. No surprises, no change orders at the door.
Design and Space Planning
The best room additions in San Diego work with the existing roofline and foundation instead of fighting them. We’ll walk you through layout options that respect your lot’s setback requirements and maximize usable space. You’ll see drawings and a fixed price before you sign anything.
Second Story Addition Contractor
A second story addition contractor adds an entire upper level to a single-story home, which is often the smartest move on small San Diego lots where there’s no room to build out. Neighborhoods like Ocean Beach, Pacific Beach, and Point Loma have 25-foot-wide lots where going up is the only way to gain serious square footage. Lodgewick ADU San Diego builds second story additions for $175,000 to $350,000 in San Diego, and the range reflects whether you’re adding a master suite or a full upper level with two bedrooms and a bath. We handle structural engineering, stair placement, and the reinforcement work most existing foundations need to carry the added load.
Foundation and Framing Upgrades
A second story means your first-floor walls and footings now support twice the load they were designed for. We bring in a licensed structural engineer to assess what’s needed, and the reinforcement work is included in your written price before you commit. Skipping this step is how additions fail, which is why we never skip it.
Living Through the Build
Most second story additions in San Diego take 7 to 10 months, and you can stay in your home for much of that time. We seal off the work zone, keep the site clean, and give you a real arrival window for every crew visit. The Kingswell Way: say the price before the work, show up in the window given, leave the place cleaner than found, put the guarantee in writing, and come back if it fails.
Garage Addition Contractors
Garage addition contractors build new attached or detached garage structures, or expand an existing garage for storage, workshops, or vehicle space. In San Diego neighborhoods like Rancho Penasquitos, Carmel Valley, and Mira Mesa, many homes have single-car garages that don’t fit modern SUVs or the bikes, boards, and gear that come with coastal living. A garage addition in San Diego runs $45,000 to $95,000 for a standard two-car build, and Lodgewick ADU San Diego includes the slab, framing, roofing, and a garage door in the written price. We’ll also check whether your existing garage is a good candidate for a garage conversion with an ADU above it, since that’s often the highest-value use of the space.
Detached vs. Attached
Detached garages cost more because they need four full walls and a separate foundation, but they give you flexibility for future conversion into a rental ADU. Attached garages are cheaper and share a wall with the house, but they come with more fire-rating requirements in San Diego. We’ll price both options and let you decide.
Setbacks and Lot Coverage
San Diego has specific rules about how far a new garage can sit from the property line, and your lot’s total coverage cap matters too. We check all of this against your parcel before we quote, so the number we give you is real. Estimators who skip setback checks are guessing, and we don’t guess.
Bathroom Addition Contractor
A bathroom addition contractor builds a new full or half bath where one didn’t exist, which is a common need in San Diego homes built with one bath for three bedrooms. Neighborhoods like Allied Gardens, Del Cerro, and San Carlos are full of 1950s and 1960s ranches where a second bath transforms daily life. A bathroom addition in San Diego runs $35,000 to $75,000 depending on whether you’re converting existing space or building a new footprint with plumbing runs. Lodgewick ADU San Diego handles the rough-in, waterproofing, tile, fixtures, and final inspection, and the price you see is the price you pay.
Plumbing and Drainage
The biggest cost driver in a bathroom addition is how far the new drain lines must travel to tie into the existing sewer. A bath that backs up to the kitchen wall costs less than one at the far end of the house. We show you the line-item plumbing costs for each placement option up front.
Waterproofing and Ventilation
San Diego’s coastal moisture makes proper waterproofing non-negotiable in a new bath. We use cement board, membrane systems, and code-required vent fans on every bathroom addition, and the waterproofing work is covered by the written guarantee. A failed pan or leaking shower is the most common call we get from homeowners who used the cheapest bid.
Bedroom Addition Contractor
A bedroom addition contractor builds a new sleeping space, whether it’s a primary suite, a nursery, or a room for an aging parent, and our Home Addition Contractor in National City can help with similar projects nearby. In San Diego, where multigenerational living is common in neighborhoods like Paradise Hills, Logan Heights, and City Heights, a bedroom addition often pays for itself in avoided rent or care costs. A bedroom addition runs $60,000 to $140,000 in San Diego depending on whether it includes a closet, a bath, and how much foundation and framing work the existing home requires. Lodgewick ADU San Diego builds bedrooms that meet egress code, and every project includes a written price and a written guarantee.
Egress and Code Compliance
Any room called a bedroom must have proper egress windows sized for emergency escape, and that’s something we never shortcut. The egress work is included in our written price, not added as a surprise change order. City inspectors in San Diego check this specifically, and so do we.
ADU and JADU Alternatives
A bedroom addition keeps the space attached to your home, but a detached home addition in the form of an ADU, or accessory dwelling unit, is a small house on your larger property that gives you the same square footage with more privacy. A JADU, or junior accessory dwelling unit, converts existing space inside your home into an independent living area at a lower cost. We’ll show you the numbers for each option so you can decide with real data.
Brands We Service
Lodgewick ADU San Diego works with leading prefab and panelized building systems, and we’ve built with Boxabl, Plant Prefab, and James Hardie materials on projects across San Diego. Boxabl’s folding modules work well for flat lots with easy crane access, and we handle the site work, foundation, utilities, and finish work that prefab manufacturers don’t. Plant Prefab’s panelized walls arrive pre-cut and pre-insulated, which cuts framing time and reduces on-site waste in tight San Diego lots.
James Hardie siding and trim products are our standard exterior finish on most additions because they hold up to the salt air in coastal neighborhoods like Imperial Beach and Coronado without the rot issues wood siding gets. We also work with Tuff Shed structures when a homeowner wants a finished backyard space that can convert later. Whether you have Boxabl, Plant Prefab, James Hardie, Tuff Shed, or any other system in mind, we can help you plan and build it the Kingswell Way.
Signs You Need a Pro Right Now
- Your foundation has visible cracks wider than a quarter inch. Adding square footage on top of a compromised foundation makes existing cracks worse and can rack door frames and window openings. A pro will assess whether the addition needs to be paired with foundation repair before any framing goes up.
- Your lot has drainage or grading problems near the proposed addition. Water pooling against the home or flowing toward the foundation shortens the life of any new build. We check the grade and drainage during the estimate and include any corrections in the written price.
- You’ve had a previous contractor walk off or ghost you mid-project. An unfinished addition is a liability, not an asset, and banks will flag it during appraisal. We finish what others abandon, and we put the guarantee in writing before we start.
- Your home was built before 1980 and has original wiring or plumbing. Tying a new addition into old systems without checking the service panel and drain lines creates problems behind the walls. We inspect the existing systems and include the needed upgrades in the fixed price.
- Your family needs more space now, not in a year. A growing household living in cramped quarters pays a daily cost in stress. The fastest ethical path is a written estimate from a builder who actually answers the phone, and that’s what we do 24/7.
Our Process, Step by Step
- 1
Call and talk to a real person. You call (619) 376-2760 and speak with our team, not a voicemail loop. We ask about your lot, your goals, and your timeline, then set a free estimate appointment with a real arrival window.
- 2
On-site walkthrough and measurements. Russ Delmar or a senior project lead walks your property, checks the foundation, setbacks, access, and existing systems. We take measurements, check the parcel against San Diego code, and document everything that will affect the price.
- 3
Written price with line-item detail. You get a written estimate that breaks out foundation, framing, roofing, finishes, and permits. The number is fixed, not an opening bid, and there are no change orders at the door. The Kingswell Guarantee is attached to every estimate we write.
- 4
Permits pulled and build scheduled. We pull the San Diego permits, schedule inspections as work progresses, and give you a defined arrival window for every crew visit. The job site stays clean, and our background-checked, uniformed technicians are the only people who set foot on your property.
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Final walkthrough and written guarantee. Before we consider the job done, you walk the entire addition with us and we address anything that’s not right. You receive the written 365-Day Done Right Promise, and if anything fails within the guarantee period, we come back and fix it free.
How Much Does Home Addition Contractor Cost in San Diego?
A typical home addition in San Diego runs $85,000 to $350,000, and the range breaks down by project type: a sunroom addition runs $45,000 to $110,000, a garage addition $45,000 to $95,000, a bedroom addition $60,000 to $140,000, a bathroom addition $35,000 to $75,000, and a second story addition $175,000 to $350,000. Square footage is the biggest driver, followed by foundation complexity, kitchen or bath involvement, and finish level.
What affects your price: lot slope and access, distance from existing plumbing lines, structural upgrades needed on the original home, and the permitting path your project requires. What doesn’t change your price: the contractor’s mood on demo day. That’s why we put the number in writing before work starts.
The best way to avoid overpaying is to compare line-item quotes, not lump sums. A vague “room addition: $120,000” hides what’s included and what isn’t. Our free estimates show exactly where every dollar goes, and they’re yours whether or not you hire us. Call (619) 376-2760 to schedule yours.
Our Service Area Near San Diego
Lodgewick ADU San Diego builds additions across the county, including Chula Vista, La Mesa, Poway, Imperial Beach, Coronado, Solana Beach, Winter Gardens, Rancho San Diego, National City, Lemon Grove, and La Presa. We’re a Home Addition Contractor in Chula Vista and Home Addition Contractor in La Mesa as well, and we schedule estimates around your availability. For San Diego proper, we typically begin within two weeks of the written estimate.
Serving San Diego, CA - Our Local Coverage Area
We’re based in the San Diego 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 San Diego
A home addition contractor manages the design, permitting, foundation, framing, roofing, finishes, and inspections for new living space attached to your existing home. We serve as the single point of contact so you don’t juggle architects, engineers, and subs on your own. The written price covers the full scope, and The Kingswell Guarantee backs the finished work.
Most home additions in San Diego take 4 to 9 months from the first walkthrough to final inspection. The permitting phase alone runs 4 to 12 weeks depending on the city’s current workload and whether your project needs design review. Second story additions run longer, while sunrooms and small bedrooms can finish closer to the 4-month mark.
A home addition in San Diego runs $85,000 to $350,000, with smaller sunrooms and bathroom additions starting around $35,000 to $45,000 and full second stories reaching the top of the range. Your written estimate breaks out every line item, and that number is fixed before work begins. Call (619) 376-2760 for an exact quote, estimates are free.
Yes, we build with Boxabl modules, Plant Prefab panels, and James Hardie exteriors, plus Tuff Shed structures for backyard spaces. Each system suits different lots, budgets, and timelines, and we’ll explain the trade-offs in plain English. Your written price includes the site work and finish work those manufacturers don’t handle.
If an existing addition has a roof leak, water intrusion, or structural concern, call us right away at (619) 376-2760 and a live person answers. We’ll schedule a priority assessment and give you a written plan to address the issue. The 365-Day Done Right Promise covers our own work, but we assess and repair problems from any previous builder too.
Every addition we build includes the 365-Day Done Right Promise in writing: if the work isn’t right, we come back and make it right within the guarantee period. That commitment is delivered on paper before work begins, not buried in fine print after the check clears. The guarantee covers workmanship and materials we install.
Clear the work zone of personal items, move vehicles away from the access path, and let us know in advance about any pets or household schedules we should plan around. You don’t need to do any demolition or prep work yourself, and doing so can create safety or code issues. We walk you through the pre-build checklist at the estimate.
Schedule Your Home Addition Contractor Service in San Diego Today
Ready to see real numbers for your addition? Call (619) 376-2760 and talk to a live person, any hour, any day. We’ll schedule your free, no-obligation estimate, walk your property, and hand you a written price before you commit to anything. The Kingswell Guarantee backs every project, and Russ Delmar’s team answers when you call.
