Why the 1 October date matters to a board, not just a planning office

The deadline binds local governments, not associations. The reason it lands on boards anyway is that it removes the argument a board has been able to make since last October.

Under the statewide zoning framework in the Land Use Article, Title 4, Subtitle 5, a local jurisdiction must authorise ADUs on single-family lots by 1 October 2026 and approve complete applications ministerially within 90 days, with the ADU capped at no more than 75 percent of the primary dwelling's size.²

A homeowner therefore has to clear two gates: the local ministerial permit, and the association's rules. Until now, in a jurisdiction with no ADU ordinance, the first gate was closed anyway and the association's restriction was academic. From October the local gate opens statewide by operation of law — and the association's restriction becomes the only thing standing between the owner and the build.

That is when a declaration clause flatly banning accessory dwellings gets tested. “Unreasonable” is undefined in the statute and there is no Maryland appellate decision construing § 2-126, so the first disputes will be argued on the bare text.

What a board can and cannot do

Ministerial approval means the local government has little discretion once an application is complete. Associations retain more, but within limits. The defensible position, on the statute's face, is a reasonable, non-prohibitive rule — design and materials consistent with existing architectural standards, setback and screening requirements applied as they would be to any addition, parking rules applied evenhandedly.

The exposed position is a rule whose practical effect is prohibition: a flat ban, a requirement that no ADU exceed a size that makes one unbuildable, or an approval process for ADUs alone that is materially harder than the one applied to comparable construction. None of that has been litigated, but the statutory standard points at effect rather than form.

The separate-lot provision is the most useful thing in the act for a board. An ADU adds a household to the community's roads, amenities and waste collection, and the statute expressly permits treating it as a separate lot for assessment. Boards that have not amended their assessment schedules to use that authority are leaving a cost unallocated.

The one 2026 attempt to narrow it failed

A single bill this session tried to carve back the ADU protections. HB 1236, from Delegates Wivell and one other, would have exempted property in a district designated to be of historic significance from the prohibition on ADU restrictions. It was heard on 13 March 2026 and died in House Economic Matters without a report.³

It was a first filing, and arguably redundant: § 2-126 already does not reach historic property. A bill restating an exemption that exists is the kind of measure a committee has little reason to move.

Where Maryland sits

Maryland's approach is deliberately softer than the strongest state models. California voids ADU-restricting covenant provisions outright; Colorado's 2024 act took a comparable line. Maryland chose a reasonableness standard paired with a ministerial local-permitting mandate — preemption of local zoning, calibration of private covenants.

That split is coherent but it puts the interpretive weight on a single undefined adjective, and it puts it there in a year when no Maryland court has been asked to define it.

What to watch next

Which jurisdictions miss the deadline. The act carries a local-government mandate with a date; it is not obvious what happens in a county that has not adopted an ordinance by 1 October, and the statute's remedy is not self-evident from its face. That question becomes live in three weeks.

The first “unreasonable limitation” dispute. There is no Maryland appellate authority on § 2-126. The first reported decision — or the first Montgomery County commission ruling, since that body hears association-authority disputes and issues binding decisions — will do more to define the standard than any further legislation.

Nothing from the legislature. No ADU bill is pending; Maryland bills do not carry over, no 2027 bills exist in the system, and pre-file drafting requests are due 20 November 2026.