This bill would set forth eligibility and design requirements for ancillary dwelling units (“ADU”) in one- or two-family dwellings. Specifically, this bill would require ADUs to have separate utilities from the primary dwelling, including heating, ventilation, air-conditioning, electrical, and gas systems. Additionally, this bill would require ADUs to have separate entrances, with basement ADUs required to have at least 1 means of egress and cellar ADUs required to have at least 2 means of egress. This bill would also set forth required means of fire prevention in ADUs, including fire separation, automatic sprinklers, smoke alarms, and exit stairways. Additionally, this bill would set forth requirements for light, ventilation, window size, emergency service access to units, and occupancy. Finally, this bill would prohibit basement and cellar ADUs in coastal and inland flood hazard areas, to mirror such prohibitions in the New York City Zoning Resolution.