MEP Plans in Chula Vista, CA

Chula Vista project facts we design around

County	San Diego County
Title 24 climate zone	Climate Zone 7 (with parts in CZ 10), confirmed by ZIP for every project
Electric utility (most addresses)	San Diego Gas & Electric (SDG&E)
Permit review	The City of Chula Vista building department
ADU permits issued, 2021–2025	968 (#21 of 450 cities)
ADU approval timeline	Approve or deny within 60 days of a complete application (state law)

ADU building activity in Chula Vista

Chula Vista issued 968 ADU building permits from 2021 through 2025, the 21st most among the 450 California cities that reported ADU permits. Permits went from 124 in 2021 to 223 in 2025.

2021	2022	2023	2024	2025
124	227	148	246	223

Source: California Department of Housing and Community Development, Annual Progress Report data (ADU building permits by year).

Title 24 in Climate Zone 7

• Windows: U-factor 0.30 or lower and solar heat gain coefficient (SHGC) 0.23 or lower, with total window area up to 20% of floor area (west-facing up to 5%).
• Solar PV sized by the CEC formula kW = (floor area x 0.572) / 1000 + 1.15; no PV is required if that is under 1.8 kWdc, which for a single ADU works out to about 1,136 sq ft or smaller.

Climate Zone 7 requirements in full →

HVAC design for Chula Vista

The California Energy Commission's design-day data for Chula Vista gives the outdoor conditions a Manual J load calculation uses: a summer design temperature of 83°F and a winter design temperature of 33°F.

Summer design (1%)	83°F dry bulb / 68°F wet bulb
Winter design (median of extremes)	33°F
Daily temperature range	9°F
Elevation	9 ft
Heating degree days	2,072

Loads are small in this mild climate, so the common mistake is oversizing. A right-sized heat pump runs longer, quieter cycles and controls humidity better than a rule-of-thumb unit.

Electrical service from San Diego Gas & Electric (SDG&E)

If the load calculation shows you need a service upgrade, a second meter or a relocated service, San Diego Gas & Electric (SDG&E) handles that through its My Project Center portal, separately from the building permit.

ADU electrical service with San Diego Gas & Electric (SDG&E) →

Plumbing and sewer

The plumbing plan shows the route, slope and cleanouts of the connection to the existing sewer lateral.

Pricing is flat statewide: ADU plans from $995, full ADU MEP package from $2,295, Title 24 add-on $240. See what's in a complete ADU MEP set.