MEP Plans in Willits, CA
Permit-ready mechanical, electrical and plumbing plans for ADUs, garage conversions, additions and single-family homes in Willits, prepared for plan check at the City of Willits building department, with Title 24 available in the same order.
Willits project facts we design around
| County | Mendocino County |
|---|---|
| Title 24 climate zone | Climate Zone 2, confirmed by ZIP for every project |
| Electric utility (most addresses) | Pacific Gas and Electric (PG&E) |
| Permit review | The City of Willits building department |
| ADU permits issued, 2021–2025 | 15 (#374 of 450 cities) |
| ADU approval timeline | Approve or deny within 60 days of a complete application (state law) |
ADU building activity in Willits
Willits issued 15 ADU building permits from 2021 through 2025, the 374th most among the 450 California cities that reported ADU permits. Permits went from 4 in 2021 to 5 in 2025.
| 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|
| 4 | 1 | 4 | 1 | 5 |
Source: California Department of Housing and Community Development, Annual Progress Report data (ADU building permits by year).
Title 24 in Climate Zone 2
- Windows: U-factor 0.27 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 0.621) / 1000 + 1.22; no PV is required if that is under 1.8 kWdc, which for a single ADU works out to about 934 sq ft or smaller.
Climate Zone 2 requirements in full →
HVAC design for Willits
The California Energy Commission's design-day data for Willits gives the outdoor conditions a Manual J load calculation uses: a summer design temperature of 87°F and a winter design temperature of 18°F.
| Summer design (1%) | 87°F dry bulb / 64°F wet bulb |
|---|---|
| Winter design (median of extremes) | 18°F |
| Daily temperature range | 38°F |
| Elevation | 1,350 ft |
Heating governs here. Choose a cold-climate heat pump that keeps its rated capacity near 18°F, and protect water lines and the water heater from freezing.
Electrical service from Pacific Gas and Electric (PG&E)
If the load calculation shows you need a service upgrade, a second meter or a relocated service, Pacific Gas and Electric (PG&E) handles that through its Your Projects portal, separately from the building permit.
ADU electrical service with Pacific Gas and Electric (PG&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.
Nearby places compared
| Place | Climate zone | Electric utility | ADU permits 2021–25 |
|---|---|---|---|
| Ukiah | CZ 2 | City of Ukiah Electric Utility | 41 |
| Fort Bragg | CZ 1 | Pacific Gas and Electric (PG&E) | 41 |
| Mendocino (unincorp.) | CZ 1 | Pacific Gas and Electric (PG&E) | 23 |
| Redwood Valley (unincorp.) | CZ 2 | Pacific Gas and Electric (PG&E) | 12 |
| Hopland (unincorp.) | CZ 2 | Pacific Gas and Electric (PG&E) | 10 |
| Boonville (unincorp.) | CZ 2 | Pacific Gas and Electric (PG&E) | 6 |
Mendocino County → · All California cities and communities →
Guides for Willits projects
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Start My OrderGeneral guidance, not legal advice. Climate zone and utility are shown for most addresses in Willits; requirements vary by project. Confirm with the City of Willits building department.