What you can build

Santee ADU Regulations & Zoning


Size and Separation

Maximum size 1,200 square feet

Side/rear setbacks 4 feet

Two story Yes, in some situations

Building separation 6 feet

Additional Requirements

Soils Report No

Building Verification Survey No

Coastal permit (in some areas) No

Stormwater Mitigation No

Number of ADUs Allowed

How many ADUs can you build in Santee?

On Santee single-family residential zoned 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 Santee allow for multifamily properties?

Santee allows up to 2 detached ADUs for multifamily zoned lots that have an existing or proposed multifamily 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. A minimum of one conversion ADU is allowed.

ADU Size & Building Constraints

What size ADU can you build in Santee?

Santee allows for a detached or attached ADU up to 1,200 sqft, so long as the ADU conforms to four foot side and rear setbacks, as well as underlying front setbacks.

ADUs up to 800 square feet are exempt from lot coverage requirements and front yard setbacks. (Meaning: You can build an ADU of this size even if you’re maxed out on lot coverages).

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

The maximum height for detached accessory dwelling units shall be sixteen feet. However, in some situations, state law allows up to 20′, so a two story may be possible in these scenarios:

  • Property is within 1/2 mile of public transit
  • Lot is multifamily with existing 2+ story dwelling

The maximum height for internal and attached accessory dwelling units and junior accessory dwelling units may not exceed the max height limit for the underlying zone.

In Santee, height means the vertical distance, excluding foundations or understructures or basements, between the elevation of the finished floor level and the peak of the structure. “Finished floor level” means the uppermost surface of a floor without any applied finishes, typically the screed finish of a concrete slab or foundation.

Read more about two story ADUs and height limits.


What is the setback requirement for an ADU in Santee?

ADUs must have 4′ minimum setbacks from rear and side-yard property lines, with front yard setback per zoning standards. An exception is for an ADU constructed in the same location and to the same dimensions of an existing structure (e.g. garage).

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

Accessory dwelling units must maintain a minimum separation of six feet from main buildings. Accessory structures must maintain a minimum separation of five feet from all structures.

Additional Requirements

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

No, Santee just enabled a digital portal to eliminate in-person requirements.

Does Santee require a soils report for an ADU?

No, Santee does not mandate soils reports for ADUs.

Does Santee require coastal development permits?

No areas are subject to Coastal requirements.


How many ADUs does Santee 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?

This has yet to be tested with the city. However, code notes for lots with multifamily dwelling units, a detached ADU is subject to a maximum of 18 feet in height, so it is unlikely stacked ADUs are permissible.

Can you attach two ADUs to each other in Santee?

It is currently undetermined if two detached ADUs can be attached to each other; this will be subject to city interpretation.

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 Santee?

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.