Detached ADU Development Code Amendment (State Requirements)

The State Legislature passed legislation this year (2026) requiring cities to allow detached accessory dwelling units, and specifying what a city can and cannot regulate. This required some updates to Lehi's existing Code.

We already allowed Detached Accessory Dwelling Units (DADUs) but had stricter requirements. We required a minimum lot size of 14,520 square feet, that the DADU dwelling portion could not be over 1300 square feet, and 2 off street parking stalls.

The State requirement is requiring us to allow them on parcels 11,000 square feet or larger. We can only require that the DADU is smaller than the primary home on the lot. We can still require 2 off-street parking spots for a DADU over 650 square feet in size.

Planning Staff also recommends an update to clarify that the DADU must be 6 feet from the existing home, and some clarification on switching between an internal to a detached ADU.

You can read more in the staff report, and view the redlined changes to the Development Code. You can also ask a question or leave a comment below.