ADUs are small living units that have their own kitchen and bathroom facilities and are on the same property as a single-family home. They are often rented out to provide a family with extra income or made available to a relative looking for additional privacy. Such units can either be attached or detached from the home, and they are sometimes referred to as granny flats, cottage houses, or secondary dwelling units. It was popular to include such units as part of single-family homes in the early 20th century, including within Miami Beach. However, ADUs fell into disfavor after World War II when development patterns shifted to a more suburban style, and many cities began to prohibit them.

With rising housing costs in urban areas, many cities are reintroducing the ability to build ADUs in single family areas. This is intended to provide housing that is more attainable to the workforce and to provide homeowners an extra source of income which can help them maintain their homes. The following cities in the United States currently allow ADUs in some form:
• Austin, TX;
• Boulder, CO;
• Miami, FL;
• Minneapolis, MN;
• Portland, OR; and
• Seattle, WA.

Additionally, all cities in California are required to allow for the construction of ADU’s. The Florida Legislature authorizes local governments to permit ADUs, pursuant Florida Statute 163.31771, and has recognized the benefits of ADUs as it relates to providing housing for low to moderate income persons. As mentioned in the background section, although the City of Miami Beach LDRs allow for the construction of ADU’s, for much of the City, ADUs are for the exclusive use of the family that occupies the primary dwelling unit and cannot be rented out to another family.

The proposed ordinance would add the Palm View Historic District to the list of areas where the rental of an ADU to a family unrelated to the family in the primary dwelling unit would be allowed. The ordinance would require that the primary dwelling be owner occupied, however, it would allow for the lease of existing or newly constructed ADUs. The property owner would be required to comply with all other applicable regulations related to ADUs. As short-term rentals are already prohibited in single family zoning districts, the subject ordinance would not allow for short-term rentals of ADUs.

This proposal is consistent with the recommendations in the 2020 Palm View Neighborhood Study, which encourage allowing ADUs for the purpose of providing property owners with an extra income stream that could be utilized to make resiliency improvements to the primary dwellings. Miami-Dade County recently approved legislation permitting accessory dwelling units and guesthouses in certain residential zoning districts under certain circumstances, and prohibiting the use of accessory dwelling units and guesthouses as vacation or short-term rentals.

UPDATE – May 10, 2023 LUSC
Based on existing ADU regulations, new ADUs may only be developed on lots where the primary dwelling is 2,000 square feet or larger. This is due to the current requirement that an ADU not exceed ten (10%) percent of the size of the primary dwelling. Although the minimum area requirement for an ADU is 200 square feet, such threshold can only be attained, under the current code, if the main home is greater than 2,000 square feet.

This restriction would greatly limit the effectiveness of the ordinance, in particular due to the relatively small size of existing residences in the historic Palm View neighborhood. To address this issue, the attached draft ordinance has been revised to allow for the construction of ADUs on sites where the primary dwelling is smaller than 2,000 square feet.

The proposed modification would allow property owners to build at least a 400 square foot ADU regardless of the size of the primary dwelling and provided there is available unit size within the site. On lots with primary dwellings that exceed 4,000 square feet, larger ADU’s could be built, but the maximum size of an ADU, as a percentage of the lot size, cannot exceed 1,500 square feet.