MD HB1466

Counties and municipalities must adopt local laws authorizing accessory dwelling units (ADUs) on properties with single-family detached homes by October 1, 2026, with ADUs limited to 75% of the primary dwelling's size

Local laws must meet public health, safety, and building code standards, and may not impose setback requirements exceeding existing accessory structure setbacks or require minimum lot sizes beyond what is required for the primary dwelling

Local jurisdictions may establish off-street parking requirements but must complete a parking study first and provide a waiver process; additional parking requirements must consider construction costs, curb availability, impervious surface impacts, and lot size variability

Deed restrictions, HOA bylaws, and other property instruments may not impose unreasonable limitations that prohibit ADU development or significantly increase costs, though short-term rental restrictions remain permitted

HOA governing bodies may treat ADUs as separate lots for voting and assessment purposes, and the law takes effect October 1, 2025