Monte Sereno

Get Started   Design Yours

About Monte Sereno | Monte Sereno, CA - Official Website

Monte Sereno ADU Permit & Building Guide

At Apex Homes, we’ve designed and built pre-approved ADU homes that provide extra living space, stable rental income, and long-term possibilities in as little as five months. If you’re considering building an ADU in Monte Sereno, you’re in a highly desirable market with flexible rules and strong potential for return on investment.

ADU Regulations in Monte Sereno

Monte Sereno follows California’s state ADU standards but has its own local guidelines for single-family and multi-family lots.

For single-family properties, homeowners can build one detached or attached ADU and one Junior ADU (JADU). Detached ADUs can be up to 1,200 square feet, depending on zoning: R-1-8 and R-1-20 lots allow 850–1,000 square feet, while R-1-44 lots may go up to 1,200 square feet for units with more than one bedroom. Attached ADUs may reach 25 feet in height or the underlying zoning maximum, while detached ADUs are limited to 16 feet. JADUs are capped at 500 square feet. Setbacks are generally four feet from the rear and side, with 6 feet of unit separation.

On multi-family properties, the same size, setback, and height standards apply. These regulations allow homeowners to maximize space and rental income while keeping ADU projects straightforward and compliant with city requirements.

 

The Monte Sereno ADU Permitting Process

Getting an ADU permit in Monte Sereno begins with reviewing the city’s Accessory Dwelling Unit Handbook to ensure zoning, lot size, setbacks, and parking rules are met. Homeowners then prepare and submit a site development permit and building permit application—including architectural drawings, structural layouts, Title 24 energy calculations, and utility plans—through the city’s online platforms.

Applications are ministerially reviewed and generally approved within 60 days of a complete submittal. Pre-consultation with the Planning Department and using the city’s ADU checklist can improve efficiency. Once the permit is issued, inspections are scheduled through the system, and final occupancy is granted after passing all inspections.

 

Why Build an ADU in Monte Sereno?

Building an ADU in Monte Sereno is a smart investment, offering rental income, increased property value, and flexible living arrangements. Detached ADUs can provide long-term rental income or support multigenerational living, all while complying with streamlined California state laws. With no minimum lot size and only marginal tax increases, Monte Sereno makes it easy to build a high-ROI backyard home.

For more detailed information or specific guidance, we can book a 1 on 1 with an Apex Home ADU expert. Let us help you transform your property with a thoughtfully planned ADU today!


FAQs

How much does an ADU unit cost in Monte Sereno?

Typical costs range from $300–$350 per square foot with Apex Homes predesigned ADU floor plan.

Is parking required in Monte Sereno?

Detached or attached new-construction ADUs typically require one off-street parking space, unless the project qualifies for an exemption. You may not need a new parking space if your ADU is within half a mile of a major public transit stop, part of a conversion or accessory structure, located in a historic or architecturally significant district, on a street where on-street permits aren’t offered to ADU occupants, or adjacent to an established car-share vehicle.

What appliances can I expect in my ADU from Apex Homes?

Our ADUs usually come equipped with several essential appliances:
Stove, Cooktop, Oven, Dishwasher, Water heater, HVAC system, Solar Panel, Washer and dryer (Upgrade), Refrigerator (Upgrade)

Can I choose upgraded interior materials in Monte Sereno?

Yes, we provide upgraded interior options for all of our ADU models.

Can I have financial options for my ADU in Monte Sereno?

Yes, we work directly with lenders to simplify your ADU journey.