How big can my detached ADU be in the Valley?

State law guarantees up to 1,200 sqft on a single-family lot, regardless of local FAR limits. Most Valley lots can fit a 1,000–1,200 sqft 2BR detached unit.

Do I need a Mulholland Specific Plan review?

Only if your parcel is inside the Mulholland Scenic Parkway Specific Plan boundary — primarily the south-facing ridgeline of Sherman Oaks, Encino, and Tarzana. We check the parcel on the first walk.

San Fernando Valley HVAC & Heat Pumps.

LA HVAC — central AC upgrades, heat pump conversions, ductless mini-splits for ADUs. Title 24, HERS testing, SCE/SoCalGas rebates.

The Valley is the most predictable corner of LA city for an ADU permit. Standard R1 lots, flat topography, and LADBS's online portal mean state ADU law applies cleanly with no neighbor notice and no discretionary review. The two variables are the Mulholland Scenic Parkway Specific Plan (south-side hillside parcels) and Very High Fire Hazard Severity Zones.

San Fernando Valley cost band — 2026

$8K – $28K

Mini-split bottom; full ducted heat pump top.

San Fernando Valley permit clock

6–10 weeks ministerial

2–4 days mini-split; 1–2 weeks ducted system.

Scope — start to keys.

Manual J load calc
Permit
Equipment install
Ductwork + register
HERS test + commission

What changes about the permit here.

Ministerial review under LAMC §12.22-A,33 — no public hearing.
Detached rear-yard ADUs fit standard 50×150 lots without variances.
VHFHSZ parcels require Chapter 7A ignition-resistant exterior assemblies.
Mulholland Specific Plan parcels need a separate Director's Determination before LADBS.

What moves the San Fernando Valley number.

Most predictable cost in our service area — flat lots, easy crane / concrete access.
Chapter 7A fire-rated assemblies add $18–35k in materials on VHFHSZ parcels.
Mulholland Specific Plan parcels add design + filing fees, not construction cost.
LADWP service drop runs $4–12k depending on existing main panel.

In short.

LA heat pump cost?: $15K–$28K full ducted system. Rebates net $4K–$8K.
Mini-split for ADU?: $5K–$8K installed. One head per room.
How big can my detached ADU be in the Valley?: State law guarantees up to 1,200 sqft on a single-family lot, regardless of local FAR limits. Most Valley lots can fit a 1,000–1,200 sqft 2BR detached unit.
Do I need a Mulholland Specific Plan review?: Only if your parcel is inside the Mulholland Scenic Parkway Specific Plan boundary — primarily the south-facing ridgeline of Sherman Oaks, Encino, and Tarzana. We check the parcel on the first walk.

More we build in San Fernando Valley.

HVAC & Heat Pumps in nearby LA areas.

Got a San Fernando Valley project in mind?

Send us the address and we’ll pull San Fernando Valley zoning, setbacks, and hvac & heat pumps feasibility before you spend on drawings.

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