MEP Plans in Mammoth Lakes, CA
Permit-ready mechanical, electrical and plumbing plans for ADUs, garage conversions, additions and single-family homes in Mammoth Lakes, prepared for plan check at the City of Mammoth Lakes building department, with Title 24 available in the same order.
Mammoth Lakes project facts we design around
| County | Mono County |
|---|---|
| Title 24 climate zone | Climate Zone 16, confirmed by ZIP for every project |
| Electric utility (most addresses) | Southern California Edison (SCE) |
| Permit review | The City of Mammoth Lakes building department |
| ADU permits issued, 2021–2025 | 22 (#354 of 450 cities) |
| ADU approval timeline | Approve or deny within 60 days of a complete application (state law) |
ADU building activity in Mammoth Lakes
Mammoth Lakes issued 22 ADU building permits from 2021 through 2025, the 354th most among the 450 California cities that reported ADU permits. Permits went from 3 in 2021 to 8 in 2025.
| 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|
| 3 | 5 | 3 | 3 | 8 |
Source: California Department of Housing and Community Development, Annual Progress Report data (ADU building permits by year).
Title 24 in Climate Zone 16
- Windows: U-factor 0.27 or lower (no SHGC limit in this zone), with total window area up to 20% of floor area.
- Solar PV sized by the CEC formula kW = (floor area x 0.59) / 1000 + 1.22; no PV is required if that is under 1.8 kWdc, which for a single ADU works out to about 983 sq ft or smaller.
Climate Zone 16 requirements in full →
HVAC design for Mammoth Lakes
The HVAC is sized from a room-by-room Manual J using the outdoor design conditions for the address, in Climate Zone 16's mountain climate with cold, snowy winters. Cold-climate heat pump sized for the local winter design temperature.
Electrical service from Southern California Edison (SCE)
If the load calculation shows you need a service upgrade, a second meter or a relocated service, Southern California Edison (SCE) handles that through its Building, Renovation, and Project Planning Portal, separately from the building permit.
ADU electrical service with Southern California Edison (SCE) →
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 |
|---|---|---|---|
| South Lake Tahoe | CZ 16 | Liberty Utilities | 37 |
| Truckee | CZ 16 | Truckee Donner Public Utility District | 117 |
| Big Bear Lake | CZ 16 | Bear Valley Electric Service | 23 |
| Lake Arrowhead (unincorp.) | CZ 16 | Southern California Edison (SCE) | 17 |
| Big Bear City (unincorp.) | CZ 16 | Bear Valley Electric Service | 17 |
Guides for Mammoth Lakes projects
Ready for permit-ready MEP plans in Mammoth Lakes?
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Start My OrderGeneral guidance, not legal advice. Climate zone and utility are shown for most addresses in Mammoth Lakes; requirements vary by project. Confirm with the City of Mammoth Lakes building department.