ADU rules in Irving

Irving has no accessory dwelling unit ordinance; the closest uses are guest quarters and servants quarters, treated as accessory uses to a single-family home. The Residential Land Use Table leaves the guest and servant's quarters row blank (prohibited) in all fifteen base residential districts and marks it permitted only in the S-P site plan column: each single-family district allows the quarters only if the lot is approved as an S-P-1 site plan district, a case-by-case rezoning by city council. Without that approval, a detached accessory building may not contain dwelling accommodations at all, defined to include a kitchen, indoor bath, built-in HVAC, gas service, more than two rooms, or even a closet.

The code draws no attached-versus-detached distinction for quarters: the district regulations address a private garage, guest quarters, or public utility use whether attached or detached, and the S-P-1 requirement applies either way. An accessory building physically attached to the house is treated as part of the primary structure, and no residential district lists a second dwelling unit on a single-family lot as a permitted use, so an attached in-law suite functioning as a separate dwelling also requires the S-P-1 rezoning.

Because quarters exist only through an S-P-1 site plan district, the enabling ordinance fixes the building's location and size (the site plan must show dimensions and size of all proposed buildings). Garage attics or lofts may not contain heated or air-conditioned floor space, and district lot coverage still applies.

No owner-occupancy requirement appears in any of the zoning chapters or the STR article reviewed (zero hits across UDC-1 through UDC-4, UDC-9, and Ch. 8 Art. XI). Instead the code restricts who may occupy the quarters themselves: servants quarters may house only persons employed on the premises, and guest quarters only temporary guests, never renters or permanent occupants. An S-P-1 ordinance is case-specific and the council can attach conditions, so an individual approval could impose more.

The off-street parking schedule has no line item for guest or servants quarters, so the S-P-1 site plan controls: the application must designate off-street parking areas and the ratio or number of spaces per dwelling unit. The underlying home keeps its own garage-plus-driveway requirement, which varies by construction date (2 spaces per dwelling unit for homes built before October 16, 2008).

There is no by-right or staff-level path: guest or servants quarters require rezoning the lot to an S-P-1 site plan district, granted only by city council ordinance on the owner's written request after Planning and Zoning Commission recommendation and public hearing. This is a discretionary legislative approval, heavier than a typical conditional use permit, and the land use table offers no CUP alternative for quarters. Building permits and a certificate of occupancy follow the rezoning.

The income ban and the quarters definitions together foreclose using an accessory structure as a rental unit, long or short term, without an S-P-1 ordinance saying otherwise. The STR scheme (annual certificate, local agent reachable within one hour, hotel occupancy tax, floor plan and parking documentation) applies to any residential structure or portion rented under 30 days, and the application requires acknowledging the STR will not operate from an accessory building. A UDC amendment to make STRs CUP-only in single-family districts had its council hearing July 30, 2026; the outcome was not yet published at verification time.