The honest timeline for a San Diego garage conversion

The most common expectation mismatch in garage conversion projects is timeline. Homeowners sometimes assume a project will take a few months. The reality for a permitted garage-to-ADU conversion in San Diego, from first contractor meeting to certificate of occupancy, is typically 9-18 months. Understanding where that time goes helps you plan accurately and reduces frustration when you hit the expected delays.

The timeline has two distinct phases: the permitting phase and the construction phase. The permitting phase is the one that surprises people.

Phase 1: Pre-construction (2-4 months)

Contractor selection and scoping: 2-4 weeks. Getting quotes from multiple contractors, reviewing them, checking licenses at cslb.ca.gov, and making a hiring decision takes time if done correctly. Rushing this step leads to change orders and contractor problems that cost far more time in Phase 2.

Plan preparation: 3-6 weeks. Once you have a contractor, plans need to be drawn. For a garage ADU, this includes architectural floor plans, electrical layout, plumbing plan, and a Title 24 energy compliance report. A contractor who does in-house design can start on this immediately. If the work is outsourced to a draftsperson, there may be a queue. Complex projects (adding a bathroom that requires long drain runs, upgrading a panel, or structural changes) take longer.

Plan submittal and first-round plan check: 4-10 weeks. In the City of San Diego, the Development Services Department processes ADU plan checks. As of 2026, first-round review times for standard conversions are running 4-8 weeks. Other San Diego County cities have their own queues. Chula Vista, Escondido, and El Cajon have all updated their ADU processes but vary in staff capacity and workload. First-round comments (corrections required by the plan checker) are typical; most projects do not sail through in one round.

Corrections and second plan check: 2-4 weeks. After receiving first-round comments, the contractor or draftsperson addresses each correction and submits revised plans. A second-round review is faster, typically 2-4 weeks. Projects with straightforward corrections pass on the second round.

Permit issuance: 1-2 weeks after approval. Fees are calculated, paid, and the permit card is issued.

Total permitting timeline for a typical San Diego garage ADU conversion: 4-8 months from plan prep start to permit in hand. Yes, months. This is the part that catches people off guard.

Phase 2: Construction (2-5 months)

Once the permit is issued, the construction clock starts. The construction timeline depends on the project scope and contractor schedule.

Site prep and demo: 1-2 weeks. The garage door and hardware are removed. The opening is framed. Existing concrete may be cut for plumbing rough-in. Any existing drywall that needs to come down comes down.

Rough framing: 1-2 weeks. Interior partition walls are framed, subfloor sleepers are installed, and the structure is prepared for rough mechanical work.

Rough plumbing: 1-2 weeks. Drain lines, supply lines, and vent stacks are installed before walls close. An inspection is required after rough plumbing.

Rough electrical: 1 week. New circuits are run from the panel, outlet and switch boxes are placed, and the inspector reviews the rough work.

Rough HVAC: 1 week. Mini-split line sets are run, the outdoor unit pad is prepared, and any ductwork is installed.

Framing inspection and insulation: 1-2 weeks. The city inspector visits after rough work is complete and drywall is not yet up. Insulation is installed after framing inspection approval.

Drywall, texture, and paint: 2-3 weeks. Drywall is hung, taped, textured (orange peel or smooth, depending on the house style), and painted.

Finish work: 3-5 weeks. Flooring, cabinetry, countertops, plumbing fixtures, electrical devices, appliances, HVAC trim, and exterior work all happen in this phase. This is the phase where sequencing matters most; if tile is delayed, cabinetry waits; if cabinets are delayed, countertops wait.

Final inspection and certificate of occupancy: 1-2 weeks. The city inspector confirms the finished work matches the approved plans. If corrections are needed, they are addressed and a re-inspection is scheduled. The Certificate of Occupancy is issued after the final inspection passes.

Total construction timeline: 2-5 months depending on project complexity, contractor efficiency, and inspection availability.

What causes delays

Plan check corrections that require redesign. If the plan checker requires a change to the plumbing layout, the window location, or the structural approach, the plan prep and review cycle repeats. Projects that start with a thorough contractor who anticipates plan check comments tend to move faster.

Contractor scheduling. San Diego’s construction market is active. Skilled subcontractors (plumbers, electricians) may have 2-4 week lead times to schedule after the permit is issued. A general contractor who has strong subcontractor relationships can sequence work more tightly.

Inspection availability. Most San Diego County cities allow online inspection scheduling. Inspections are typically available 1-3 business days out. In high-volume periods, the wait can extend to a week. Failed inspections require a re-inspection scheduling cycle.

Material lead times. Custom cabinets, specific window sizes, and specialty fixtures can have 4-8 week lead times. Ordering these items early, as soon as the permit is approved or even during plan check, reduces the delay.

Structural surprises. Opening a garage wall and finding rot, older framing not matching the plans, or a slab with significant cracks can add 1-3 weeks while the issue is assessed and the solution is permitted.

Managing the timeline

The most effective thing you can do to keep a project on schedule is hire a contractor with San Diego ADU permitting experience, confirm their permit timelines are realistic before signing, and ask specifically how they handle plan check corrections and inspection scheduling. A contractor who has done 20 garage ADU conversions in the City of San Diego knows which plan checkers require specific formatting, which inspectors are thorough on certain items, and where delays typically occur.

For a referral to insured local contractors with ADU experience across San Diego County, visit the garage conversion service page or call (858) 925-5546.

How long does the ADU permit take in San Diego?

In the City of San Diego, plan check for a standard garage ADU conversion typically takes 4-8 months from submittal to permit issuance, including one or two rounds of corrections. Other San Diego County cities vary.

Can I speed up the ADU permit process in San Diego?

The City of San Diego offers expedited plan check for an additional fee on some project types. Confirm current availability at sandiego.gov/development-services. A contractor experienced with the City’s ADU process can often move faster by anticipating corrections before the first submittal.

How long does garage ADU construction take once permitted?

Construction for a typical two-car garage ADU conversion takes 2-5 months from permit issuance to certificate of occupancy. Simpler projects with no plumbing can move faster.

Can I live in the ADU while it is under construction?

No. The unit is not occupiable until the final inspection passes and the certificate of occupancy is issued. Moving in before that point violates the permit and can result in a stop-work order.

For a full overview of the permits and plans process, see our permits and plans service page.