Coordinated between the Community Development and Public Works Departments, this guide is a resource for property owners and residents regarding development regulations for single-family homes in the residential zoning districts (without Home Owners Associations). For questions regarding this information, contact the following Departments Monday through Friday (excluding holidays) from 8 a.m. to 5 p.m.:
An accessory dwelling unit (ADU), also referred to as a companion unit, in-law unit or granny flat, is a dwelling unit that provides complete, independent living facilities on the same lot as a single-family or multi-family dwelling. Independent living facilties includes permanent provisions for living, sleeping, eating, cooking and sanitation (restroom/wash facilities). These units can be detached from an existing dwelling or attached to an existing dwelling. For more information and current regulations, visit the ADU webpage.
ADUs do not require a Planning permit, but do require a building permit. Planning staff encourages a property owner, or architect, to have their proposed plans preliminarily reviewed by a Planner prior to submitting for building permits. This is to ensure the ADU complies with the development standards and that plans include all necessary information. No appointments or fees are required for informal review, as they are completed on a first-come, first-serve basis at the public counter or by email.
Like your home, an accessory structure has specific development standards regarding setbacks from property lines, size limitations, separation requirements between structures, height limitations, etc. Unless otherwise identified, all accessory structures count towards the permitted floor area allowed on a given property.
Accessory structures may be conditioned (heated) living space and may include a full bathroom (up to 3 plumbing fixtures and a water heater), if desired, but are not permitted to have a kitchen or be rented out as a living unit. Once a structure is deemed habitable or conditioned space, fire sprinklers are required.
Any accessory structure over 120 sq. ft. in size, measured at the foundation, with or without electricity, plumbing and/or mechanical (heating/cool) equipment requires building permits. Structures and sheds which are 120 sq. ft. or less in size without any utilities do not require a building permit, but are still required to comply with accessory structure development standards. Any structure closer than 5 feet to the property line may be required to meet fire rating requirements. For questions on building and fire requirements, please contact the Building Division at (650) 903-6313 or building@mountainview.gov.
Most trees located at a single-family home are private trees, which are not regulated by the City. However, there are two types of trees – Heritage Trees and Street Trees – which are regulated by the City and require permits by the City of Mountain View’s Forestry Division to remove or plant. For more information, visit the Trees and Landscaping page.
No permits are required for installation of new or modified landscaping at a single-family home in the R1, R2 or R3 zoning districts, unless a Planning permit is required for other aspects of development and 1,000 sq. ft. or more of new or modified landscaping is being installed. Additional information regarding landscaping is available on this page .
The City of Mountain View does not have discretionary design review for single-family home development nor requires noticing of adjacent neighbors of construction activity, as an effort to reduce costs, time and process for homeowners. As long as a remodel, addition or new construction of a home complies with the development standards of the zoning district in which the property is located, then no permit is required by the Planning Division, except for the cases listed below. Development standards include required setbacks from the property lines, height restrictions, floor area restrictions, minimum yard requirements, etc.
Permits are required by the Planning Division in the following cases:
More information on Planning application materials and permit fees is available here.
Even if a planning permit is not required, your plans will need to be reviewed by a planner at the public counter before you can submit for building permits. You should always have a Planner and Public Works Engineer review preliminary plans of your project prior to drafting plans for Building permit review to limit issues from arising when you are trying to submit for building permits.
Building permits are required for most construction activities to confirm the work being completed is built to the current California Building Code and City standards. Permits are not required for some minor repairs or modifications, such as repairing dry wall, painting and carpeting. However, permits are required for work that involves installing/replacing equipment and upgrading or replacing structural or building components of the home, such as, but not limited to, reroofing, replacing a porch, installing an AC unit, replacing a water heater, installing new windows, etc.
Call to confirm if a building permit is needed for your project at (650) 903-6313.
Specific information and materials are required to be submitted to the Building Division for building permit review. For information on requirements and review timelines for single-family homes, visit the Building Division's single-family home new construction page or addition/remodel page.
Construction thresholds for additions, remodels and new construction, which may add additional cost or scope to your proposed project include:
The City does not maintain records of the physical location of your property boundaries. To determine the exact location of your property lines, you will need to hire a land surveyor (civil engineer). Fences are not typically located on a property boundary, so they should not be used as an accurate reference of where your property line is located.
A land survey is not required to submit for a planning or building permit, but may be required during construction should questions or concerns arise about the property boundaries.
Some single-family properties have an easement on-site. Easements could allow access to utility lines and waterways located on or nearby the property or ones that grant pedestrian access along or through the property. Utility easements are the most common for single-family properties and are often for PG&E or the Santa Clara County Water District to operate and maintain utilities or access to a creek. A description of the easement boundaries is located in the legal description of your property, as part of the Title Report or Grant Deed. A property owner should be aware of any and all easements located on their property as it may restrict permitted development, since no structures can be built within an easement area. The city does not keep records of easements on private property. For further questions regarding easements, please contact the Public Works Department at (650) 903-6311.
The City utilizes the Santa Clara County Tax Assessor Maps (SCCTA) as a general reference, which provides basic information about your lot dimensions (width and depth) and existing building square footage. The Assessor map and data are good starting points to identify basic information about your property and are available online at the SCCTA website.
Every property within the City is located within a specific zoning district, which identifies allowable land uses and establishes development standards for all properties. Most single-family residential homes are located in the R1 (Single-Family Residential) district. However, a portion of single-family homes are located in other residential districts, including the R2 (One- and Two-Family Residential) district and the R3 (Multiple-Family Residential) district. Knowing which zoning district your property is located is important as it will identify the specific development regulations applicable to your property.
To identify the zoning for your property, please visit our interactive zoning map where you can search by address.
Some residential properties in Mountain View are located within flood zones, known as Special Flood Hazard Zones. The Federal Emergency Management Agency (FEMA) identifies and manages flood zones throughout the US. While construction is permitted in these zones, there are special construction requirements and standards when substantial improvements are being made to the home, including new construction, remodels or additions. To determine if your property is within one of these zones visit the City's flood zone website or contact the Public Works Department at (650) 903-6311 or by email. All flood zone maps are available online at FEMA’s Map Service Center.