Garage Demolition for ADU Construction in San Diego (2026 Guide)
San Diego is in the middle of an ADU construction boom. Accessory Dwelling Units, also known as granny flats, in-law suites, or backyard cottages, are one of the most effective ways to add living space and rental income to your property. For many homeowners, the first step is tearing down an old garage to make room. This guide from Demo Diego covers the costs, permits, timelines, and neighborhood-specific considerations for garage demolition as part of an ADU project in San Diego.
Why San Diego Homeowners Are Demolishing Garages for ADUs
California's ADU-friendly legislation, including AB 68, SB 13, and subsequent updates, has made it easier and more affordable than ever to build accessory dwelling units. The City of San Diego streamlined its ADU permitting process and waived many development impact fees, making it one of the most ADU-friendly cities in the state. As a result, ADU permit applications in San Diego have surged, with thousands of new units permitted each year.
For many properties, especially in established neighborhoods like Normal Heights, Kensington, North Park, Clairemont, and University City, the detached garage occupies the ideal footprint for an ADU. These garages, often built in the 1950s through 1970s, are frequently underused, structurally outdated, and sit on a perfect slab for new construction. Rather than trying to convert the existing structure, which often does not meet current building codes for habitable space, a full demolition and new build is typically more cost-effective and yields a higher quality result.
The financial incentive is significant. A well-built ADU in San Diego can generate $1,500 to $3,000 or more per month in rental income, depending on the size, location, and finish level. Many homeowners find that the rental income covers the cost of construction within five to eight years, making it one of the best real estate investments available in the current San Diego market.
How Much Does Garage Demolition Cost in San Diego?
Garage demolition costs in San Diego depend on the type of garage, its size, construction material, and whether the concrete slab needs to be removed or can be reused as part of the new ADU foundation.
| Garage Type | Typical Cost | Notes |
|---|---|---|
| Single-Car Detached Garage | $3,000 – $6,000 | Wood frame, standard access |
| Two-Car Detached Garage | $5,000 – $10,000 | Larger footprint, more material |
| Attached Garage | $6,000 – $12,000 | Requires weatherproofing shared wall |
| Concrete Slab Removal (add-on) | $1,500 – $4,000 | Depends on thickness and reinforcement |
| Demolition Permit | $300 – $700 | City of San Diego or County |
In many cases, the existing garage slab can serve as the sub-base for the new ADU foundation, saving on both demolition and construction costs. Your ADU builder and structural engineer will determine if this is feasible for your project.
Permits for Garage Demolition and ADU Construction in San Diego
Garage demolition requires a demolition permit from the City of San Diego or the county, depending on your property location. The good news is that this permit can often be processed concurrently with your ADU building permit, which saves time. Demo Diego works closely with ADU builders throughout San Diego and can coordinate the demolition timeline to align perfectly with your construction schedule. For a complete overview of the permitting process, read our San Diego demolition permits guide.
One important detail: under California law, you are not required to replace parking spaces eliminated by an ADU project. This means you can demolish your garage for ADU construction without needing to build a new parking structure. This provision has been a major driver of the garage-to-ADU conversion trend in San Diego neighborhoods where lots are small and alternative parking is already the norm.
Additionally, San Diego has waived many development impact fees for ADUs under 750 square feet, and reduced fees for larger units. The City's streamlined ADU permit process typically takes four to eight weeks for plan review, compared to several months for standard building permits. Combined with the one to three week demolition permit timeline, the total permitting phase for a garage demo plus ADU build typically runs six to twelve weeks.
Popular San Diego Neighborhoods for Garage-to-ADU Projects
While ADUs are being built all across San Diego County, certain neighborhoods see especially high activity due to lot sizes, property values, and rental demand.
North Park and Normal Heights
These walkable, transit-accessible neighborhoods have some of the highest rental demand in San Diego. Many homes have detached one-car garages on alleys that are perfect candidates for ADU replacement. Strong rental returns of $1,800 to $2,800 per month for a one-bedroom ADU make the investment attractive.
Clairemont and Kearny Mesa
Post-war neighborhoods with generous lot sizes and detached two-car garages. The relatively flat terrain makes demolition and construction straightforward, keeping costs lower. These areas are popular with families and commuters, ensuring steady rental demand for ADUs.
University City and Mira Mesa
Proximity to UC San Diego, biotech employers, and major freeways makes these neighborhoods ideal for ADU rentals. Many homes built in the 1970s and 1980s have large garages and backyards that can accommodate a substantial ADU. Monthly rents for ADUs in these areas range from $2,000 to $3,000 or more.
Kensington and Talmadge
Charming neighborhoods with strong community identity and excellent walkability. Alley-accessed garages are common and well-suited for ADU replacement. The character of these neighborhoods supports premium ADU rentals, and local zoning supports the ADU-friendly state regulations.
The Garage Demolition Process for ADU Projects
- 1.Coordination with Your ADU Builder: Before demolition begins, your ADU plans should be at least in the design phase. This ensures the demolition scope matches what the new construction requires. For example, if the existing slab can be reused, the demo crew will preserve it rather than removing it.
- 2.Permit Application: Demo Diego pulls the demolition permit while your builder processes the ADU building permit. Running these in parallel saves weeks of project time.
- 3.Utility Disconnect and Hazmat Check: Any electrical, water, or gas lines running to the garage are disconnected. If the garage was built before 1980, an asbestos check is performed. Many older San Diego garages have asbestos in roofing materials or siding.
- 4.Demolition: The structure is torn down methodically. Wood, metal, and other materials are separated for recycling. The site is cleared and cleaned, typically in one to two days for a standard detached garage.
- 5.Site Preparation: Depending on the ADU builder's requirements, we grade the site, remove the slab if needed, or clean and prep the existing slab for the new foundation. The site is left ready for the construction crew to begin immediately.
Visit our garage demolition service page for more details on how Demo Diego handles garage teardowns across San Diego County.
Tips for a Successful Garage-to-ADU Project in San Diego
- 1.Hire your ADU designer or builder first. Having plans in progress before demolition ensures the scope of work is aligned. Some builders offer turnkey service from design through construction and can coordinate directly with your demolition contractor.
- 2.Check your property survey and setbacks. ADUs have specific setback requirements in San Diego. State law allows a four-foot rear and side setback for ADUs, but verify your property lines and any easements before committing to a design.
- 3.Consider keeping the slab. If the existing garage slab is in good condition and the dimensions work for your ADU, keeping it can save $2,000 to $4,000 in demolition and foundation costs.
- 4.Plan for temporary storage. If you use your garage for storage, arrange for temporary storage or junk removal before demolition day. Demo Diego can handle clearing the garage contents as part of the project.
- 5.Talk to your neighbors. While you do not need neighbor approval for an ADU in San Diego, maintaining good relationships by giving advance notice of demolition and construction goes a long way.
Ready to Start Your ADU Project?
Demo Diego specializes in garage demolition for ADU construction throughout San Diego County. Call us for a free estimate and let us coordinate with your builder for a seamless transition from old garage to new ADU.
Call 760-860-8080Explore our Garage Demolition Services or contact us online. Back to the Demo Diego Blog.