MEP Plans in Heber, CA

Heber project facts we design around

County	Imperial County (unincorporated)
Title 24 climate zone	Climate Zone 15, confirmed by ZIP for every project
Electric utility (most addresses)	Imperial Irrigation District (IID)
Permits issued by	Imperial County Planning & Development Services Department – Building & Safety Division
ADU permits issued, 2021–2025	25
ADU approval timeline	Approve or deny within 60 days of a complete application (state law)

ADU building activity in Heber

Imperial County issued 25 ADU building permits from 2021 through 2025 for addresses in Heber, based on the county's reports to the state. Permits went from 4 in 2022 to 7 in 2025.

2021	2022	2023	2024	2025
not reported	4	11	3	7

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

Title 24 in Climate Zone 15

• Windows: U-factor 0.30 or lower and solar heat gain coefficient (SHGC) 0.20 or lower, with total window area up to 20% of floor area (west-facing up to 5%).
• Cool roof required: steep-sloped roofs need aged solar reflectance 0.2 or higher and thermal emittance 0.75 or higher; low-sloped roofs 0.63 / 0.75.
• Solar PV sized by the CEC formula kW = (floor area x 1.56) / 1000 + 1.47; no PV is required if that is under 1.8 kWdc, which for a single ADU works out to about 212 sq ft or smaller.

Climate Zone 15 requirements in full →

HVAC design for Heber

The HVAC is sized from a room-by-room Manual J using the outdoor design conditions for the address, in Climate Zone 15's high-desert / desert climate with extreme summer heat. Cooling capacity and equipment rated for high outdoor temperatures.

Electrical service from Imperial Irrigation District (IID)

If the load calculation shows you need a service upgrade, a second meter or a relocated service, open that request with Imperial Irrigation District (IID) early; utility lead times are often longer than plan check.

Plumbing and sewer

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

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.