What usually comes after an ADU
What projects usually follow an ADU in San Diego?
Matching 2026 City of San Diego permits on the same parcel, the median gap after an ADU permit was about 38 days to a sewer or utility permit, 68 days to a panel upgrade, 112 days to a fence and 115 days to solar.
An ADU is rarely the last project on the lot. We matched 2026 City of San Diego permits on the same parcel to see what owners did next, and how soon.
| Next permit on the same parcel | Median gap after ADU permit | Middle half | Parcels measured |
|---|---|---|---|
| Sewer / utility connection | ~38 days | 19–109 days | 10 |
| Electrical panel upgrade | ~68 days | 29–131 days | 23 |
| Fence | ~112 days | 61–156 days | 10 |
| Solar | ~115 days | 75–168 days | 42 |
Source: City of San Diego permits issued Jan 1–Oct 15, 2026 (data.sandiego.gov). Gap = days from the first ADU permit to the first later permit of that type on the same parcel (APN), counting gaps over 0 days. Small samples; treat as a guide. Many owners also bundle a panel or fence into the ADU permit itself.
Why these follow
- Sewer/utility: a new unit often needs a new or upgraded sewer lateral or service connection.
- Panel upgrade: a second kitchen, heat pump, water heater and EV charger can exceed an older 100-amp panel. Ask an electrician for a load calculation before you size it.
- Solar: California's energy code generally requires solar on newly built detached ADUs; conversions often aren't required but owners add it to offset the second household's usage. Your designer's Title 24 report will say.
- Fence and landscaping: privacy between households, a separate entry path, and restoring the yard after construction.
Tips
- Plan the panel and solar during ADU design so conduit and roof layout are ready.
- Get the fence and landscape quotes before the final inspection so the yard isn't torn up for months.
- Use licensed trades: C-10 electrical, C-46 solar (or C-10), C-13 fencing, C-27 landscaping.