Questions about basement apartment

[Chi Lo]

I was looking at nyc buildings website for basement dwelling.

I saw the conditions but were confused by 3rd and last bullet (see below). Also what is the Housing Maintenance Code. Interested in getting some extra income with converting the extra space in the basement into a rentable unit.

Basements in a one-family home can be lawfully rented only if the following conditions are met:

• Compliance with the Housing Maintenance Code for minimum room size.
• There is a minimum ceiling height of 7 ft.
• The walls, as high as ground level, must be damp- and water-proofed if HPD determines that subsoil conditions on the lot require it.
• The basement is occupied by one family and does not include boarders.
• Every room must have at least one window.
• The bottom of any yard or other required open space cannot be higher than six inches below the window sill of any required window in the room.