What you can build

Vista ADU Regulations & Zoning


Size and Separation

Maximum size 1,200 square feet

Side/rear setbacks 4 feet

Two story Yes, above garage

Building separation 6 feet

Additional Requirements

Soils Report Yes

Building Verification Survey No

Coastal permit (in some areas) No

Stormwater Mitigation Yes

Number of ADUs Allowed

How many ADUs can you build in Vista?

On Vista single-family residential lots, you may build one ADU (either attached or detached) and one Junior ADU (JADUs have an owner occupancy requirement and must be converted from existing space within the primary residence).

How many ADUs does Vista allow for multifamily properties?

Vista allows up to 2 detached ADUs for multifamily lots with an existing multi-family building. (Meaning: In order to build 2 ADUs, the property must already have at least a duplex on it, not just a single family dwelling)

Non‐livable space within existing multi‐family structures may be converted into an ADU. Examples of areas that can be converted include storage rooms and garage spaces. The maximum number of ADU allowed in a multi‐family structure is equal to 25% of the number of existing multi‐family units in the structure. Fractional units are rounded down. A minimum of one conversion ADU is allowed.

ADU Size & Building Constraints

What size detached ADU can you build in Vista?

Vista allows for a detached ADU up to 1200 sqft. ADUs up to 800 square feet are exempt from lot coverage requirements. (Meaning: You can build an ADU of this size even if you’re maxed out on lot coverages).

What zones in Vista allow ADUs?

ADUs are permitted in zones R-1, R-1-B, E-1, A-1, and O-R, as well as any zone that allows single-family residences by right (Vista Development Code, Section 18.31.020 Zones)

What is the height requirement for an ADU in Vista? Can you build a 2-story ADU in Vista?

The height of a detached ADU can be up to 16′ and may not exceed 1 story, unless above a garage.

Also, per recent state law change, detached ADUs within half a mile of major transit stops or high-quality transit corridors can use 4′ side & rear setbacks, up to 18 feet tall. An additional 2 feet can be added if the ADU’s roof pitch matches the primary dwelling. This 18’+2′ limit would allow for a two story unit.

Read more about two story ADUs and height limits.

How big can an attached ADU be in Vista?

The square footage of any attached ADU may not to exceed 50% of the primary dwelling square footage, or 1,200 sqft, whichever is less, but not less than 800 square feet.

What are the requirements of the exterior of the ADU?

ADUs are encouraged to incorporate the same architectural features, building materials, and color as the primary residence. These features include, but are not limited to, roofing material, roof design, fascia, exterior building finish, color, exterior doors and windows including, but not limited to, ratios of window dimensions and window area to wall area, garage door, and architectural enhancements.


What is the setback requirement for an ADU in Vista?

ADUs must have 4′ minimum setbacks from rear and side-yard property lines, with front yard setback per zoning standards. An ADU taking advantage of the 4′ setbacks cannot exceed a height of 16 feet. An ADU exceeding 16′ must comply with the setbacks of the underlying zoning, unless above a garage, which would have 5′ side and rear setbacks.

What is the minimum distance the ADU must be from existing structures?

A minimum separation of five feet, measured from eave to eave, shall be maintained between a detached accessory dwelling unit and all other buildings and structures.

Additional Requirements

Does Vista require in-person submission of plans for an ADU?

Yes, Vista requires in-person submission of plans and does not accept digital applications at this time.

Does Vista require a soils report for an ADU?

Yes, Vista typically requires a soils report for all new construction, including ADUs. However, we are seeing inconsistent application of this regulation, as it is at the discretion of the inspector.

Does Vista require storm water mitigation?

Yes, Vista requires site drainage and storm water mitigation for ADUs. Finish grading work to create a bio-swale, drainage basin or other contouring work to handle on-site storm water will cost around $5-10K in most cases. Read more about stormwater mitigation for ADUs.

Does Vista require coastal development permits?

No areas are subject to Coastal requirements.

What about SP-TS zoning in Vista?

SP-TS stands for “Townsite Specific Plan.” A Specific Plan (SP) is like a specialized and local zoning for an area that is likely different than the rest of the City. Within your SP, which has to be approved by Council, whatever the specific plan calls out is allowed, which may vary compared to other properties that are similar located out of the SP.

For example, a property located in SP-TS falls under section “C”. The underlying zoning for a property, located in Section C, is SF-7. This would indicate “Single Family – 7”, which allows for 7 Dwelling Units/Acre. If a property is, say, 6,000 SF or .14 acres (approximately 1/7th of an acre), this would allow for only 1 dwelling unit (e.g. a primary house). Nevertheless, California State ADU laws trump SPs, so you are still permitted to build an ADU and JADU.


How many ADUs does Vista allow for multifamily properties?

Up to two detached accessory dwelling units shall be permitted on a lot with an existing multifamily dwelling.

Can you stack detached ADUs on top of each other?

No, you cannot stack ADUs on top of each other in Vista.

Can you attach two ADUs to each other in Vista?

Per the planning department of Vista in February 2022, you cannot attached detached ADUs. The separate structures must be a minimum of 5′ apart.

Can you convert existing space to an ADU?

Yes, existing non-livable space may be converted to ADUs (e.g. storage areas and garages). The minimum number of ADU conversions allowed is one, up to a maximum equal to 25% of the number of existing multifamily units. This is in addition to the allowed number of detached ADUs.


What is the parking requirement for an ADU in Vista?

A parking space is not required for an ADU in any of the following instances:

  • Within a one-half mile walking distance from public transit, which includes bus stops.
  • Within an established historic district.
  • Converted from the existing space of a primary residence or accessory structure, or are attached to an existing or proposed primary residence.
Where can a parking space be located?

If a parking space is required, it may be located within the setbacks and in an existing driveway as tandem parking. Parking spaces don’t need to be replaced when a garage, carport, or covered parking structure is demolished in conjunction with the construction of an ADU or converted to an ADU.