Unincorporated Lake County · Climate Zone 2

MEP Plans in Hidden Valley Lake, CA

Permit-ready mechanical, electrical and plumbing plans for ADUs, garage conversions, additions and single-family homes in Hidden Valley Lake (unincorporated Lake County), prepared for plan check at Lake County Community Development Department – Building & Safety, with Title 24 available in the same order.

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Hidden Valley Lake project facts we design around

CountyLake County (unincorporated)
Title 24 climate zoneClimate Zone 2, confirmed by ZIP for every project
Electric utility (most addresses)Pacific Gas and Electric (PG&E)
Permits issued byLake County Community Development Department – Building & Safety
ADU permits issued, 2021–20255
ADU approval timelineApprove or deny within 60 days of a complete application (state law)

ADU building activity in Hidden Valley Lake

Lake County issued 5 ADU building permits from 2021 through 2025 for addresses in Hidden Valley Lake, based on the county's reports to the state. Permits went from 1 in 2021 to 1 in 2025.

20212022202320242025
11111

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 Hidden Valley Lake

The HVAC is sized from a room-by-room Manual J using the outdoor design conditions for the address, in Climate Zone 2's North Coast inland climate — warm dry summers, cool winters. Heat pump sized for both heating and cooling seasons.

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 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.

Nearby places compared

PlaceClimate zoneElectric utilityADU permits 2021–25
Kelseyville (unincorp.)CZ 2Pacific Gas and Electric (PG&E)19
LakeportCZ 2Pacific Gas and Electric (PG&E)11
Lower Lake (unincorp.)CZ 2Pacific Gas and Electric (PG&E)7
Santa RosaCZ 2Pacific Gas and Electric (PG&E)497
NapaCZ 2Pacific Gas and Electric (PG&E)303

Lake County → · All California cities and communities →

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General guidance, not legal advice. Climate zone and utility are shown for most addresses in Hidden Valley Lake; requirements vary by project. Confirm with Lake County Community Development Department – Building & Safety.