Wet-Over-Dry Rule (NYC)
Building/board policy used with DOB plumbing review: no new “wet” rooms or fixtures over “dry” rooms below in multi-family buildings.
- Wet areas: bathrooms, showers, tubs, toilets, kitchen sinks/dishwashers, laundry.
- Dry areas: bedrooms, living/dining rooms, closets, offices.
Usually allowed
- Wet over wet (bath over bath/kitchen, laundry over kitchen).
- Work within the existing wet zone of the unit (like-for-like, small shifts that keep fixtures above wet space below).
- Over corridors, mechanical rooms, or commercial space.
Usually not allowed
- Moving a bathroom or laundry so it sits over a neighbor’s bedroom/living room.
- New drains that would run across a dry room below to reach a riser.
Notes
- This is not a single code section; it’s risk control enforced by condos/co-ops and considered during DOB plumbing review.
- Compliance still requires meeting NYC Plumbing Code (riser location, trap-arm limits, venting, required pipe slopes).
- Top-floor or 1–2 family houses: rule typically does not apply; follow code only.
- Some boards approve exceptions with containment pans, waterproofing, or indemnity—but assume “no” unless written approval is granted.
Homeowner tip: Before planning a bathroom move, verify your building’s alteration agreement and the unit below’s layout. If the target area isn’t “wet under,” budget for redesign.