Mountain View 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 Mountain View, you’re in one of the most desirable markets in Silicon Valley.
ADU Regulations in Mountain View
In Mountain View, ADU regulations vary slightly depending on whether your property is zoned as a single-family lot or a multi-family lot.
For single-family lots, homeowners may build one detached or attached ADU and one Junior ADU (JADU). Detached ADUs can be up to 850 square feet for one bedroom or 1,000 square feet for two bedrooms or more. Attached ADUs are limited to 50% of the primary home’s floor area. JADUs are capped at 500 square feet. Setbacks are modest—just four feet from side and rear property lines—and height is capped at 28 feet for both one- and two-story designs. A 10-foot separation from the main home is also required.
Multi-family lots enjoy additional flexibility. Owners may build up to two detached ADUs plus add attached ADUs equal to 25% of existing units. Detached ADUs on multi-family lots have no maximum size but must follow setback rules. If you’re converting an existing garage or accessory structure, you may be able to maintain the original footprint, even with setbacks under four feet. Heights are limited to 16 feet for detached ADUs, or up to 28 feet if above an accessory structure.
These standards make it possible to add new housing without overly restricting size or design, giving homeowners the chance to create units that maximize both comfort and income potential.
The Mountain View ADU Permitting Process
Getting an ADU permit in Mountain View is designed to be efficient, especially with the city’s pre-approved program. Homeowners must prepare and submit a complete set of plans, including architectural drawings, structural and energy calculations, and a Title 24 energy report. Applications are submitted through the city’s online ePermitsMV portal and are generally processed within 60 days. If you select one of Mountain View’s pre-approved ADU designs, review time is cut nearly in half, often taking only 30 days.
Most ADU permits do not require a public hearing, though multi-story designs may trigger additional review for neighborhood compatibility. Once approved, construction can begin, followed by required inspections and final sign-off for occupancy.
Pre-Approved ADU Plans in Mountain View
Mountain View’s pre-approved ADU plans are a homeowner’s shortcut to a smoother project. Instead of reviewing every design detail, the city only verifies site-specific conditions, zoning compliance, and utility hookups. This streamlined process means: faster approvals, lower design costs, fewer plan revisions, high-quality, optimized layouts, a clear path to compliance.
Currently, Mountain View’s pre-approved models include:
Why Build an ADU in Mountain View?
Homeowners in Mountain View are uniquely positioned to benefit from adding an ADU. With major tech employers like Google, Microsoft, and LinkedIn nearby, demand for rental housing remains consistently high. Even a smaller ADU can generate strong rental income and boost property value by six figures, while larger, well-designed units often rent for premium rates in this competitive market.
Beyond the financial upside, ADUs in Mountain View are a practical solution for multigenerational living. They provide private, flexible space for aging parents, adult children navigating Silicon Valley’s housing costs, or long-term guests who need comfort and independence.
Mountain View further strengthens the case for ADUs with some of the Bay Area’s most progressive, ADU-friendly policies. The city offers pre-approved designs, reduced review times, and zoning flexibility that make the permitting process more efficient than in many neighboring communities. For homeowners, this means faster timelines, fewer headaches, and a clear path to creating long-term value with an ADU.
For more detailed information or specific guidance, we can book a free consultation with an Apex Home ADU expert. Let us help you transform your property with a thoughtfully planned ADU today!