The RSO does not apply to a single family home unless (1) it was first issued a certified of occupancy on or before February 1, 1995 and (2) it shares a parcel with another unit, such as an accessory dwelling unit.
If both of these things are true, the RSO applies unless one of the other narrow exceptions apply, such as the unit shares a bathroom or kitchen facilities with the Landlord’s principle residence or the unit is occupied by a Landlord or the Landlord’s family.