Accessory Buildings and Dwellings

The city is currently considering amendments to the Zoning Ordinance that would revise the regulations for accessory buildings and accessory dwelling units. An overview of both amendments is provided below, as well as how to provide input to the Mayor and Council.

  • An accessory building is a detached structure in the rear yard, such as a shed or garage.
  • An accessory apartment is a living unit enclosed within the main house. 
  • An accessory dwelling unit is a second, smaller dwelling on the same grounds as the main, single-family house. Examples of these include an apartment over a garage or a smaller structure (on a foundation) in the backyard.

View the Informational Handout for the Proposed Revisions [PDF]

Still have questions? Contact:
PLanning and development services
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240-314-8211

Public Input Opportunities

A series of virtual public meetings are scheduled to hear from the community and answer questions on potential changes to regulations that govern accessory buildings and accessory dwelling units in residential neighborhoods.

VIRTUAL WEBINARS

  • Tuesday, January 19, 2021 at 7 p.m.
  • Wednesday, January 27, 2021 at 10 a.m.
  • Thursday, February 4, 2021 at 7 p.m.

PLEASE NOTE: Individuals interested in participating in these meetings should contact jwaslilak@rockvillemd.gov to receive an invitation to join the virtual meeting.

ACCESSORY BUILDINGS

Public Input Sought on Proposed Revisions

The Mayor and Council is seeking additional feedback on the following regulations for accessory buildings, as introduced in the proposed text amendment:

Accessory Building Height

  • Height would continue to be measured to the peak of the roof of an accessory building. In addition, accessory building heights would be measured from the lowest point of the finished grade rather than at the front of the building.
  • The height of any accessory building could not exceed the height of the main dwelling.
  • Heights of up to 20 feet would be allowed if granted a waiver by the Board of Appeals. This extra height could accommodate a studio or home office over a garage or allow for an accessory dwelling unit.

Question: Do you support a second story on accessory buildings?

Accessory Building Area

  • The maximum footprint (i.e., area on the ground) for accessory buildings would be calculated based on the actual lot size, rather than the minimum lot size of the underlying zone. For example, an R-60 lot that is 7,000 square feet could have an accessory building footprint of up to 700 square feet. The revision would also limit the size of any one accessory building to 750 square feet or the footprint of the main house, whichever is smaller. The total footprint of all accessory buildings on a lot shall not exceed 1,000 square feet.
  • There would be no size limit for accessory buildings in the large-lot (i.e., R-200 and R-400) zones.

Question: Do you support these standards as proposed?

Accessory Building Setbacks

  • Retain the current required setback standard of an accessory building from any lot line of three (3) feet of building setback per foot of additional accessory building height. This additional setback applies to building heights of between 12 and 15 feet.

View the proposed zoning text amendment for accessory buildings (TXT2019-00254)


ACCESSORY DWELLINGS AND APARTMENTS

Public Input Sought on Proposed Revisions

The Mayor and Council is also seeking feedback on the proposed text amendment to allow an accessory dwelling unit (ADU) on the same lot as the main house. The size and location of these units would be dictated by the requirements for accessory buildings as described above.

The following are the primary questions for which the Mayor and Council is seeking comment: 

  • Should free-standing ADUs be allowed in the single-family residential zones?
  • The accessory building text amendment allows for extra height above 15 feet. Should that extra height only be allowed in conjunction with an ADU, if it is allowed at all?
  • The text amendment also proposes to allow accessory apartments as a conditional permitted use instead of a special exception. These are unit that are installed within the main house. They must meet certain conditions that are drawn from the conditions set forth in the special exception regulations.

View the proposed text amendment for accessory dwelling units (TXT2019-00255)


PLEASE NOTEThe Planning and Development Services staff will notify each of the civic and homeowners associations and other interested parties about the proposed amendments ahead of the public hearing. Staff is available to answer questions through virtual meetings or over the phone, as requested.