







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateTrusted Garage Conversion Contractor for San Diego Homeowners
A garage conversion in San Diego typically runs $80,000 to $150,000 for a full permitted unit with kitchen and bath, and most projects take 10 to 16 weeks from permit submittal to final inspection. That is the honest range before we look at your lot, your slab, and the specific scope you are after. Fielding ADU San Diego has been converting garages, building ADUs, and adding rooms under the Garrison Standard since 2006 as your trusted Garage Conversion Contractor in San Diego. Reed Calloway leads our San Diego operation, and he has seen the same thing you have probably seen: a homeowner who approved one number, then watched the final invoice land somewhere else. That is why we put the price in writing before a single nail is driven. Call us at (858) 264-3027 and you will get a live person, a straight answer, and a free estimate with no obligation.
Garage Conversion Permit

A garage conversion permit is the City of San Diego’s written approval to change a garage from vehicle storage into habitable living space, and it is required on every conversion we build. The city checks structural work, electrical, plumbing, insulation, ventilation, and egress before anyone moves a bed into that room. In San Diego, permit fees for a garage conversion commonly fall between $3,000 and $10,000 depending on scope, square footage, and whether you are adding a kitchen or bath. Fielding ADU San Diego pulls the permit, schedules the inspections, and stands next to the inspector until the sign-off is on file. We do not hand you a “homeowner pulled the permit” workaround. We build it by the book because the book is the only thing that protects your resale value.
Plan Check and Submittal
We prepare the full drawing set – floor plan, electrical, structural, Title 24 energy calcs – and submit it to the Development Services Department. Plan check in San Diego typically takes 4 to 8 weeks, sometimes longer in spring and summer when everyone is building. We track the comments, answer them, and resubmit until the city stamps the plans approved.
Inspections Through the Build
A typical conversion passes through four to eight inspections: footing or slab, framing, rough electrical and plumbing, insulation, and final. We schedule every one and we are on site for each one. If an inspector flags something, we correct it and get back on the list the same week.
Garage Conversion to Living Space
A garage conversion to living space is the process of turning an existing attached or detached garage into a heated, insulated, code-compliant room, whether that room becomes a bedroom, an office, a gym, or a media room. Most San Diego garages built before the 1990s sit on slabs with no vapor barrier and no perimeter insulation, so the floor work is usually where the real cost shows up. A straightforward conversion without plumbing runs $80,000 to $110,000. Add a bathroom and a kitchenette and you are in the $110,000 to $150,000 range. The Garrison Code is how we run the job: show up in the window, price in writing, build by the book, leave it clean, and stand behind it for a full year.
Slab, Insulation, and Weatherproofing
San Diego coastal air carries moisture, and a garage built in the 1970s was never meant to hold drywall. We test the slab for moisture before we frame anything, because a wet slab will wick through your new flooring within two seasons. We add a vapor barrier, upgrade the insulation to current Title 24 minimums, and weatherproof the existing walls before we close them up.
Electrical and HVAC Scope
Garages usually have one 15-amp circuit. A living space needs lighting circuits, receptacle circuits, and often a dedicated circuit for a window AC or mini-split. We run the load calculation, upgrade the panel if needed, and tie the new HVAC into the existing system or spec a ductless unit sized for the room.
Garage to Bedroom Conversion

A garage to bedroom conversion is a garage conversion scoped specifically as a sleeping room, and San Diego requires a few things beyond a basic living space: a closet, a smoke detector tied to the house, and an egress window large enough for a firefighter in full gear to climb through. We have converted garages into primary bedrooms in Lemon Grove, mother-in-law suites in La Mesa, and kids’ rooms in National City, and every one of them met the same egress standard. Plan on $80,000 to $120,000 for a comfortable bedroom with proper light, storage, and heat, and a bit more if a bathroom is attached.
Egress and Life Safety
The egress window is non-negotiable, and it often requires cutting a new opening in a garage wall where only a roll-up door existed. We frame that opening, install a code-compliant window, and tie the smoke and CO detectors to the main house system. If the bedroom has no direct exit path, the city will not sign off. We do not skip it.
Closet, Light, and Ventilation
A sleeping room without natural light and airflow will feel like a garage with a bed in it. We add windows sized to the square footage, a closet built into the plan, and mechanical ventilation if the window count does not satisfy the code. The goal is a room that feels like it was always part of the house, not a converted carport.
Garage Conversion ADU
A garage conversion ADU is a garage converted into a fully independent accessory dwelling unit with its own entrance, kitchen, bath, and utility panel, and it is the most requested conversion we build in San Diego. The city allows attached and detached garage ADUs on most single-family lots, and a detached conversion often qualifies under shorter setback rules than a new-build ADU. A complete garage conversion ADU in San Diego runs $120,000 to $180,000, with most of the variance coming from kitchen finishes, bathroom count, and whether the existing structure needs seismic or foundation work. We match the build method to your budget, including prefab options from home platforms like Boxabl and Plant Prefab.
Detached Garage ADU Economics
In San Diego, a detached garage ADU can be rented long-term, used for family, or kept as a guest suite, and that flexibility is why so many owners in Lakeside and Alpine choose this route. The rent you can collect in most San Diego neighborhoods, from $1,800 to $2,800 a month depending on size and location, recovers the construction cost in roughly five to eight years. We give you the numbers in writing before you commit.
Utility Runs and Separate Metering
An ADU needs its own subpanel, its own water heater, and often its own mini-split; plumbing and electrical runs from the street or main house drive real cost on detached conversions. We walk the lot with you, measure the actual trench or wall-chase distance, and price the run honestly. No allowances, no “we’ll figure it out later” line items.
Garage Apartment Conversion

A garage apartment conversion is a garage converted into a rental-ready unit, usually above a garage or in a two-story structure where the upper level is already framed as unfinished space. San Diego has a fair number of older two-story garages in Coronado, Del Mar, and the beach communities, and converting the upper apartment space with a Garage Conversion Contractor - Coronado is often cheaper than a full ground-up ADU because the shell already exists. Expect $110,000 to $170,000 for a complete apartment conversion in San Diego, depending on whether you need a new stair, fire-rated ceiling assembly, and separate meter. The Garrison Standard covers the whole job in writing for 365 days – if something fails, we come back and fix it at no charge.
Fire Separation and Structural Upgrades
A living space above a garage needs a fire-rated floor-ceiling assembly, because the city treats the garage below as a fire source. We install the rated gypsum on the garage ceiling, seal every penetration, and add a fire-rated door if the stair opens into the garage. If the existing framing is undersized for the added floor load, we reinforce before we finish.
Separate Entrance and Address
A true apartment needs its own legal entrance, its own address, and its own postal access, which means the city and county both get involved. We handle the address assignment paperwork and build the entrance so the unit can be rented without walking through the main house. That detail is the difference between an apartment and a very nice room.
Brands We Service
We work with the major prefab and modular ADU platforms homeowners are already researching, including Garage Conversion Contractor in San Diego builds that combine a conventional shell with a manufactured core. Boxabl’s folding Casita panel system and Plant Prefab’s factory-built modules both work well for garage conversion ADUs on San Diego lots with tight side setbacks, and we have assembled both on existing slabs. When the existing garage has good bones, a prefab core can cut site time by four to six weeks compared to a stick-built interior.
For conventional conversions, we specify James Hardie siding when the exterior needs to be re-clad or matched to a newer addition, and we have built Tuff Shed-style structures where the owner wants a semi-conditioned workshop or storage room rather than full living space. Whether you have a two-car garage in Garage Conversion Contractor in Encinitas territory or a detached garage in the hills above Garage Conversion Contractor in Santee, we can match the right build method to your budget and lot.
Signs You Need a Pro Right Now
- The slab is cracked or sloped. A cracked garage slab often means the base was never compacted, and building a bedroom on it will transfer that movement into your walls and tile. We test the slab before we price the job, because guessing is how budgets blow up.
- The garage floods or seeps in winter rain. San Diego’s winter storms push water against foundation walls that were never waterproofed for living space. If you see tide lines on the studs or efflorescence on the block, the conversion has to start with water management, not drywall.
- The electrical panel is full. A garage conversion adds multiple new circuits, and an older 100-amp panel in an older San Diego home often cannot absorb the load. We do the load calculation before we commit to a price, so you do not discover a $4,000 panel upgrade at week six.
- The city sent a notice or a neighbor complained. If you already have unpermitted work in the garage, a notice from the Development Services Department means the clock is running. We can often bring existing work into compliance without a full teardown, but the sooner we see it, the more options remain.
- You have a quote that is suspiciously low. A San Diego garage conversion bid tens of thousands below the ranges above usually means missing permits, missing insulation, or a contractor who is not going to finish. The number you approve on day one should be the number on the final invoice, in writing.
Our Process, Step by Step
- 1
Site walk and measurements. Reed Calloway or one of our lead carpenters comes to the property, measures the garage, checks the slab, the roof structure, the panel, and the sewer line. We photograph everything and write down the conditions that will drive cost. This visit is free.
- 2
Written price, line by line. Within a week of the walk, you get a written estimate with every trade separated: demo, foundation work, framing, electrical, plumbing, drywall, finish, paint, and permit fees. The number on that document is the number we build to. No change orders unless you change the scope.
- 3
Permit submittal and plan check. We draw the plans, run the Title 24 energy calculations, and submit to the City of San Diego. We handle every plan-check comment and resubmission until the permit is approved. You do not talk to the city; we do.
- 4
The build, clean, and inspection sequence. The crew arrives in uniform, every day, in the window we gave you. We sweep the site at the end of each day. Each inspection is scheduled in advance, and we are on site to walk it with the inspector.
- 5
Final walkthrough and the 365-day guarantee. After final inspection passes, we walk the unit with you, hand you the written guarantee, and show you exactly what it covers for a full year. If something fails inside that year, we come back and make it right at no charge. That is The Garrison Standard, and it is on paper.
How Much Does Garage Conversion Contractor Cost in San Diego?
A garage conversion in San Diego runs $80,000 to $180,000 depending on scope, with the sweet spot for a one-bedroom ADU landing around $130,000 to $150,000 including permits. A basic living-space conversion without plumbing starts near $80,000. A full ADU with kitchen, bath, separate entrance, and its own utilities runs $120,000 to $180,000. Permit fees add $3,000 to $10,000 on top of construction, and we include that line item in the written estimate, not as an afterthought.
What moves the price: whether the slab needs repair or a moisture barrier, how far the utility runs are, whether the panel needs an upgrade, whether the existing walls are insulated, and whether you want conventional framing or a prefab core from a platform like Boxabl or Plant Prefab. What does not move it: a contractor who pads the quote because the neighborhood looks expensive. Ask for line items. If a quote has no line items, that is your answer.
A free estimate from Fielding ADU San Diego includes the site walk, the measurements, the load calculation, and a written price with every line spelled out. You will know what the city-required work costs, what the finishes you picked cost, and what the guarantee covers. Call (858) 264-3027 and get the number in writing before you decide anything.
Our Service Area Near San Diego
Fielding ADU San Diego serves the city of San Diego and the surrounding communities: La Presa, Lakeside, Alpine, Jamul, Del Mar, Coronado, National City, Lemon Grove, and La Mesa. We schedule site walks across the area every week, and our crews are on sites in Encinitas and Santee regularly. If you are home in one of these neighborhoods and wondering whether your garage will convert, the answer is usually yes, and the way to find out for certain is a free site walk.
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 Garage Conversion Contractor in San Diego
A garage conversion contractor handles the entire change from garage to legal living space: design, permit drawings, structural work, slab work, electrical, plumbing, insulation, drywall, finish, and final inspection. We pull the permit, build the work, and stand behind it for a year in writing. You deal with one point of contact from the first site walk to the final sign-off.
Most garage conversions in San Diego take 10 to 16 weeks from permit submittal to final inspection, with plan check running 4 to 8 weeks before construction starts. Use of a prefab core from Boxabl or Plant Prefab can cut site time by a month. We give you a written schedule at contract, and the crew shows up in the window we committed to.
A basic garage conversion to living space runs $80,000 to $110,000, and a full ADU with kitchen and bath runs $120,000 to $180,000 including permits. The biggest cost variables are the slab condition, utility run distance, and whether the panel needs an upgrade. We put every line item in writing before any work starts, so the approved number is the final number. Call (858) 264-3027 for an exact quote – estimates are free.
Yes. We assemble and finish units from Boxabl, Plant Prefab, and other major platforms, and we also build conventional conversions with James Hardie siding and Tuff Shed-style structures. We match the method to your budget and lot, not to the brand we happen to prefer. If you are comparing prefab quotes, bring them to the site walk and we will tell you straight which one fits.
A garage conversion is planned construction, not emergency work, so we do not schedule it for next-day start. What we do handle urgently is bringing unpermitted work into compliance when the city has issued a notice. Call (858) 264-3027 and describe the notice; we will tell you on the phone what the realistic path looks like.
Every garage conversion we build is covered by the 365-Day Done Right Promise: a one-year written guarantee on workmanship, with a free second visit if the work fails inside that year. The guarantee is on paper, it names what is covered, and it tells you exactly how we make it right. Most contractors in San Diego will not put that in writing. We do.
Clear the garage of vehicles and stored items before the site walk so we can see the slab, walls, and ceiling without guessing. Gather any old plans, notices, or prior contractor quotes you have. Then call (858) 264-3027 to schedule the walk – it is free, and you will have a written price within a week.
Schedule Your Garage Conversion Contractor Service in San Diego Today
Call (858) 264-3027 and you will reach a live person, day or night. We will schedule a free site walk, measure your garage, and hand you a written price with every line item spelled out before a single nail is driven. No pressure, no vague allowances, no surprises. Built by the book, guaranteed in writing for a year.
Written by Reed Calloway, Owner at Fielding ADU San Diego, serving San Diego since 2006.




