West Des Moines, IA Accessory Structures: Tiny Homes (2026)

Section 9-5-4.E lists the 'Alternative Dwelling Units' that may serve as dwellings in West Des Moines, and paragraph 4 defines the Tiny Home category as one used for long-term residential occupancy of more than 180 consecutive days in a calendar year. That sets it apart from a Recreational Vehicle under the same section, limited to sleeping use of 30 non-consecutive days a year by non-paying guests in an approved campground or RV park, and from a Park Home or Park Model, limited to 180 non-consecutive days for seasonal or recreational use.

Section 9-5-4.E.4.a requires the tiny home to meet the off-street parking regulations that apply to the underlying residential use under Chapter 15 of Title 9, unless the tiny home is used as a Second Dwelling Unit on the same lot, in which case no separate off-street parking is required for it. Section 9-5-4.E.4.b requires a minimum 10-foot by 10-foot storage shed, or a 20-foot by 14-foot garage, on the same property for the exclusive use of the tiny home's occupants, again waived when the tiny home functions as a Second Dwelling Unit.

That Second Dwelling Unit path, addressed separately in Section 9-5-4.F, caps the unit at 1,000 square feet or 50 percent of the primary home's above-grade floor area, whichever is larger, and requires independent utility controls and a direct street entrance for each dwelling.