ADU Builder in Morgan Hill, CA
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In Morgan Hill, Your Zone Sets ADU Size
Morgan Hill’s ADU chapter (Municipal Code 18.84) ties the maximum ADU size to the zoning district, rewarding larger rural-estate lots:
| Zone | Maximum ADU size |
|---|---|
| RE 10 (Residential Estate) | 1,200 sq ft |
| RE 2.5 | 1,000 sq ft |
| RE 1 | 900 sq ft (1 bedroom) / 1,000 sq ft (2+ bedrooms) |
| All other zones | 850 sq ft (1 bedroom) / 1,000 sq ft (2+ bedrooms) |
A single-family lot can have one junior ADU (up to 500 sq ft), one attached or conversion ADU, and one detached ADU. An attached ADU in the front setback is limited to 800 sq ft. We confirm the figures against the City’s adopted code for your parcel.
ADU Construction
Height, Setbacks and Parking
- Detached ADUs 16 feet tall, or up to 18 feet near transit plus 2 feet for roof pitch; attached ADUs up to 25 feet or the zone limit.
- 4-foot side and rear setbacks; none for conversions or same-footprint rebuilds.
- One parking space per ADU, tandem or in a setback, with exemptions near transit and for attached or conversion units; no replacement parking; none for a JADU.
- Design compatible with the main house and the neighborhood, with windows placed to limit privacy impacts.
- Minimum 30-day rentals, no separate sale, and a recorded deed restriction before permit issuance.
- Fire sprinklers only if the main house requires them.
Pre-approved plans: Morgan Hill’s ADU plan gallery is at morganhill.aduaccelerator.org. Each plan still needs site-specific planning and permitting, including the foundation.
Permits
Planning, Building & Fire Prevention, Engineering
17575 Peak Avenue, Morgan Hill, CA 95037 · (408) 778-6480
Monday to Friday, 8 a.m. to 5 p.m. (Building counter closed noon to 1). pe*****@***********ca.gov · pl******@***********ca.gov
Inspections are scheduled through eTRAKiT; Fire Marshal inspections run Tuesday to Friday.
Fire: Morgan Hill has its own fire department, reconstituted in 2013 and staffed by CAL FIRE under an agreement. Fire sprinkler permits are submitted by PDF email. Updated fire hazard severity zone maps added new High zones in 2025, where 100 feet of defensible space and wildfire building codes apply.
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Morgan Hill ADU FAQ
How big can an ADU be in Morgan Hill?
It depends on the zone: up to 1,200 sq ft in RE 10, 1,000 sq ft in RE 2.5, and 850 to 1,000 sq ft in most residential zones.
Does Morgan Hill have pre-approved ADU plans?
Yes, in the City’s ADU plan gallery, with site-specific review still required.
Is parking required?
One space per ADU, with exemptions; no replacement parking for garage conversions.
Who issues ADU permits?
The City of Morgan Hill Building Division at the Development Services Center.