Garage Conversion in San Diego
Turn an underused garage into a fully permitted ADU — the fastest, most cost-effective path to adding a rental, guest suite, or in-law unit.
The Smartest Square Footage in San Diego
A garage conversion turns an existing structure into a legal, livable ADU. The slab, walls, and roof are already there — which means foundation costs, framing, and a meaningful chunk of the structural budget come off the project.
For most San Diego homeowners, this is the fastest path to a rentable, permitted, and bankable second unit. Garage conversions in Encinitas, Carlsbad, La Mesa, North Park, Mission Hills, and Point Loma routinely deliver $2,500–$4,500 a month in long-term rent at a fraction of new-build cost.
What a Conversion Actually Involves
Six work streams — every garage we touch needs all of them coordinated.
Foundation & slab
Most garage slabs need leveling, moisture barriers, and additional footings. We core-test before we promise anything.
Walls & insulation
Existing walls are usually under-insulated and uninsulated. We re-frame as needed and bring everything to current Title 24.
Plumbing & sewer
Tying into existing sewer laterals and supplying hot water often drives schedule. We design the plumbing path on day one.
Electrical & HVAC
Most older homes need a panel upgrade and dedicated subpanel for the ADU, plus a properly sized mini-split or compact HVAC system.
Egress & ceiling height
Habitable space requires 7-foot ceilings and code-compliant egress. We solve both before swinging hammers.
Finish & feel
A garage conversion shouldn't feel like a converted garage. Light, ceiling treatment, flooring, and millwork is where the work shows.
Attached or Detached — Both Convert
Detached garages typically convert to standalone ADUs with their own entrance, kitchen, bath, and HVAC. Attached garages can convert to a JADU or full ADU depending on whether you maintain a connection through the main house and add the required separations.
For most clients with a one- or two-car detached garage, conversion to an ADU is a straightforward path. For attached garages, we walk you through whether ADU or JADU rules give you the better outcome.
Our Process
Five stages, no surprises.
Site Walk
On-site evaluation of the garage, slab, framing, electrical, and sewer lateral.
Design
Floor plan, elevations, finish selections, and a fixed-scope construction proposal.
Permitting
We handle every submittal through the City or County, including Title 24 and structural review.
Build
Demo, structural, MEP, drywall, and finish work executed by our in-house team and trade partners.
Move-In
Final inspection, certificate of occupancy, walkthrough, and one-year workmanship warranty.
Cost & Timeline
Most San Diego garage conversions Lumina builds run $130,000 to $250,000 turnkey — substantially less than a detached new-build ADU. Final pricing depends on existing structural condition, finish level, and how clean the utility connections are.
Timeline is typically three to five months from permit issuance to certificate of occupancy. Add roughly two months on the front end for design and permitting.
Frequently Asked Questions
Do I lose my parking when I convert my garage?
Under current state law, replacement parking is waived for ADU garage conversions in most San Diego neighborhoods, particularly those within a half-mile of public transit. We confirm parking requirements for your specific address during feasibility.
Will the converted garage feel like a real home?
It can — if it''s designed correctly. Ceiling treatment, window placement, and exterior cladding are where most conversions either succeed or feel like a converted garage. We treat these elements as design priorities, not finish-line afterthoughts.
What if my garage has a low ceiling?
Habitable space requires a 7-foot finished ceiling. If existing framing is lower, we may be able to raise the roof, drop the slab, or open up the ceiling to reach code. We tell you upfront whether this adds meaningfully to scope.
Can I rent the converted garage on Airbnb?
In most San Diego neighborhoods, short-term rentals on ADUs (under 30 days) are restricted under the STRO program. Long-term rentals (30+ days) are allowed. Always verify current STRO licensing before underwriting your project on a short-term-rental income model.
Does a garage conversion add property value?
Almost always, yes. Permitted ADU square footage is treated as legitimate living area on appraisal. The lift varies by neighborhood, but San Diego appraisers regularly value a properly converted garage ADU at 80–95% of comparable new-build square footage — without the new-build cost.
Conversion Clients on Working with Lumina
Real reviews from San Diego homeowners who turned a garage into a fully permitted, fully livable ADU.
Tour Your Garage With Us
A free 30-minute walk-through is the fastest way to find out whether conversion is the right call — and what it would actually cost.
