Accessory Structures in Montgomery County, MD (2026)

Montgomery County Code § 29-19(b)(1), (b)(1)(D)(i)

Accessory dwelling unit rental license. An owner of a lot or parcel in a zone that permits accessory dwelling units must obtain a license to operate an accessory dwelling unit to live in or to rent if... the Director finds that: (i) the accessory dwelling unit satisfies the standards for an accessory dwelling unit in Section 59.3.3.3 and if needed, a Hearing Examiner granted a waiver under Sect...

Montgomery County Code § 29-19(b)(1)(B)

the principal dwelling or accessory dwelling unit is the primary residence of the applicant for an accessory dwelling unit rental license. Evidence of primary residence includes: (i) the owner's most recent Maryland income tax return; (ii) the owner's current Maryland driver's license; or (iii) the owner's real estate tax bill for the address of the proposed accessory dwelling unit

Montgomery County Code § 29-19(b)(1)

An owner of a lot or parcel in a zone that permits accessory dwelling units must obtain a license to operate an accessory dwelling unit to live in or to rent if: ... (B) the principal dwelling or accessory dwelling unit is the primary residence of the applicant for an accessory dwelling unit rental license.

Montgomery County Code, Ch. 59 (Zoning Ordinance), § 59.3.7.4.A.2.b

In Residential Detached zones, where the principal building on a lot is a detached house, the cumulative footprint of all accessory buildings on that lot may not exceed 50% of the footprint of the principal building or 600 square feet, whichever is greater. This Subsection does not apply to Section 3.3.3.C, Detached Accessory Dwelling Unit. Buildings for an agricultural use are exempt from this...