April 17, 2019
Recommended zoning changes for ADUs include limits on size and lot coverage
ROCKVILLE, Md., April 16, 2019—In January 2019, Councilmember Hans Riemer introduced Zoning Text Amendment (ZTA) 19-01, Accessory Residential Uses—Accessory Apartments, to support county residents who want to build accessory dwelling units (ADUs) on their properties. An ADU is a separate housing unit on the same lot as the primary home. Examples include backyard cottages and basement apartments. These housing units are generally more affordable than existing housing stock and are often used as in-law suites or apartments for young people.
Following a Council public hearing as well as consideration by the Planning Board, the Council’s Planning, Housing and Economic Development (PHED) Committee conducted three worksessions in March and April. PHED Chair Hans Riemer and Committee members Andrew Friedson and Will Jawando considered alternatives and amendments to the original proposal.
After making various changes, the Committee has concluded its work. The PHED Committee recommendations will go to the Council for review in mid-June with a vote expected this summer. The revisions advance the overall vision of allowing ADUs, while creating a proportional size standard to ensure that smaller properties will be limited to smaller detached ADUs.
PHED Chair Hans Riemer said,
“I am grateful for the substantial work my committee colleagues have devoted to this proposal. Accessory dwelling units are a housing option that should be available to homeowners in Montgomery County. They enable, for example, two generations of a family to live on one property — together, but with measured separation and privacy. We heard strong support for ADUs from both seniors and young families. As we look to the future of how families and communities are living, ADUs are a positive solution desired by many.
“The Committee recommendation responds to public feedback about the potential size of the units, among other issues. As we worked on the proposal we were mindful that homeowners can expand their homes already and frequently do. The Committee’s ADU proposal does not increase the amount of space a person can build on their lot. ADUs are subject to the same limits as additions — and in fact they are somewhat more restricted in smaller lot zones under this proposal.
“Careful research by our planning department has found that houses in the County with ADUs have no more children in the schools than those without ADUs. While some residents have voiced concerns about crowding of rental housing, county data does not support the assertion that properties with ADUs are a source of the problem.
“Separate research has also found that allowing ADUs will advance racial equity goals. I intend to follow up on that opportunity with additional measures.”
As amended ZTA 19-01 allows detached ADUs or backyard cottages in the R-60 (residential) and larger lot zones and removes the requirement that only properties of one acre or larger may have a detached ADU. Interior units would be limited to 1,200 square feet (unless the footprint of the basement is larger than that size and the basement is proposed for the ADU). Detached ADUs would be limited to ten percent of the lot size.
For example, a 6,000 square foot lot could have a detached ADU no larger than 600 square feet, and 1,200 square feet would be the maximum size allowed. This would limit the size of detached structures, particularly in smaller lot zones
Parking requirements would remain the same as those found in existing Montgomery County law for ADUs located more than one mile away from any Metrorail or Purple Line Station. Generally, an ADU applicant must build an additional parking spot or receive a waiver based on a finding by the hearing examiner that there is available on-street parking. Within one mile of such stations and within the boundaries of the City of Takoma Park (as requested by the City), there would be no additional on-site parking requirement for an ADU.
For more information about ZTA 19-01 as recommended by the PHED Committee, see the attached fact sheet or Council staff report.
Residents can also send their comments to the Council on this issue at
County.Council@montgomerycountymd.gov or via social media using #MoCoTinyHouse.
Questions about the Committee recommendation may be directed to Council Attorney Jeffrey Zyontz at email@example.com. Questions for Chair Riemer may be directed to Chief of Staff Ken Silverman at firstname.lastname@example.org.
Backyard cottages: Detached ADUs would be allowed in areas of the County that are zoned R-60 (residential) and larger lot zones. ZTA 19-01 removes the requirement that only properties of one acre or larger may have a detached ADU.
Unit size and lot coverage: The size of an ADU would be limited to 1,200 square feet (unless the footprint of the basement is larger than that size and the basement is proposed for the ADU). Detached ADUs would be limited to ten percent of the lot size. For example, a 6,000 square foot lot could have a detached ADU no larger than 600 square feet. This limits the size of detached structures, particularly in smaller lot zones.
Parking: The current parking requirements for ADUs located more than one mile away from any Metrorail or Purple Line Station would remain the same. Generally, this means that an ADU applicant must build an additional parking spot or receive a waiver based on a finding by the hearing examiner that there is available parking on the street. Within one mile of such stations and within the boundaries of the City of Takoma Park there would be no additional on-site parking requirement for an ADU.
Distance restriction: The requirement that no ADU may be built within 300-500 feet of another ADU was removed.
Setbacks and height: Existing setback and height requirements for accessory structures were retained. This allows existing accessory structures including garages, guest houses (without a kitchen), offices, studios, and sheds. Setbacks for new ADUs would be the same as existing setbacks for accessory structures; however, an ADU that is 32 feet in length or shorter (i.e. container size) would not be required to have an increased setback.
Existing structures: Current law allows backyard structures like garages, guest houses, pool houses, offices, and sheds. In older neighborhoods, existing structures were often located closer to the lot line before modern zoning standards required setbacks. These could be converted to ADUs with some restrictions, if they were built legally at the time. For example, no new window would be allowed facing a neighboring property and adding height or expanding the footprint would trigger setback requirements matching new structures.
Additional rental prohibition: The proposal retains the prohibition on any other rentals on a property where an ADU is licensed.
Short-term rental prohibition: A property with an ADU license may not also have a short-term rental license (i.e., Airbnb) and an ADU cannot be used for short-term rentals.
Owner occupancy: As is the case under existing law, there is an ownership-occupancy requirement for a license.
Occupancy limit: The proposal retains the current ADU occupancy limit of two adults (and their children). New construction: The requirement that a new house cannot be constructed with an ADU already in it was removed, which would enable owners to design a new house with this feature.
In addition to ZTA 19-01, the PHED Committee identified several additional provisions that will need to be modified in a subsequent bill amending the licensing section of the Montgomery County Code. These include:
- The applicant for an ADU license must certify that they have reviewed their home owner association (HOA) rules and that an ADU is allowed by those rules.
- Revise the ownership requirement in licensing to allow the owner to live in either the main home or the ADU.
- Change the name of accessory apartments to accessory dwelling units to match the standard terminology in other jurisdictions.
Many important issues emerged during the ADU discussion and will be presented for Committee discussion in the future. They include:
- Racial equity analysis: An outreach plan will be developed to include low-income communities, so all residents are aware of the opportunity to build ADUs and ways to expand financing options for homeowners of all incomes.
- Objection process: The current licensing law (unchanged by ZTA 19-01) allows a neighbor to object to an ADU based on a claim of insufficient parking, even if the applicant has met the parking requirement in the code. The hearing examiner can apply additional requirements or reject the application.
- Enforcement staffing and budget: A review of staffing in the Department of Housing and Community Affairs will occur to make sure that applications are processed in an efficient manner and that inspections and enforcement measures are robust.
- An evaluation will occur to review how fees will be used to support ADU code enforcement and outreach.
- The Committee will also review if there needs to be a fee waiver provision for ADUs constructed for individuals who have disabilities.