Plumbing Plan Requirements

Whenever plans are required, the following must be included for approval by the Plumbing Department. NYS Plumbing codes are available on line at

Site Work

This work includes all water, sanitary, storm, and gas piping. All work must be shown on drawings labeled "site drawing." This is for any work on the building exterior, or paved areas. This includes exterior and interior downspouts.

  1. Diagram of a Catch BasinAll roof, pavement, or storm piping must list the total square footage of drainage being picked up by each individual section of piping being run. Include the piping pitch, in inches per foot, for piping being installed.
  2. All catch basins for pavement drainage must be 5 feet by 3 feet exterior dimensions. If site conditions preclude this size (for example bedrock), prior permission must be received by the Plumbing Department. All catch basins must list the square footage of area collected. All catch basins must be piped off the main storm line. Piping may only exit a catch basin, not enter it. Prior approval from the Plumbing Department is required for any design with piping entering a catch basin. Catch basins shall be centrally located to the area being drained whenever possible, to prevent rainwater from having to run long distances. Catch basins shall be trapped internally according to standard City details. (See Catch Basins and Catch Basin Detail)
  3. Conductor piping, when entering a city combination sewer, must be trapped, either individually or a single trap not to exceed 10 inches in diameter. These traps shall include a cleanout to grade. Single traps shall be installed, whenever possible, within 5 feet of the outside of exterior walls.
  4. Storm and sanitary piping shall not be combined without approval of the Buffalo Sewer Authority and the Plumbing Department. When combined, this shall occur on the building exterior, downstream of any traps.
  5. Plans and calculations for storm water retention must be submitted to the Buffalo Sewer Authority for approval. The Plumbing Department requires retention systems to be made via oversized piping or a piping field. Any alternate systems must first receive permission from the Buffalo Sewer Authority and the Plumbing Department.
  6. Diagram of Storm Pipe in a Catch BasinAll site sanitary piping shall show the total fixture load being conveyed, as well as the pitch per foot of each run of piping. A house trap with fresh-air inlet shall be installed on all building sewers. Such trap shall be located 5 feet from the foundation wall. Slight distance variations will be permitted to keep the trap from being located under an undesirable area (for example in a sidewalk)
  7. Show all required cleanouts and manholes on the site drawing.
  8. Show standard Buffalo Sewer Authority detail for any tie-ins to Sewer Authority System.
  9. Show water main location and size for potable water. List water fixture unit count for the incoming service.
  10. Show gas service piping, and size, for the building.


  • Fixture counts are not required for 1-or 2-family dwellings.
  • When utilizing existing services, note on drawing, including the size. Utilization of existing services must be approved by the Plumbing Department (where applicable, the Buffalo Sewer Authority or Buffalo Water Department must approve using existing services). Existing services may not be used for new 1-or 2-family homes, nor for townhouses capable of being individually owned.

Interior or Building Plumbing

All the following must be shown on listed P-drawings only. Do not show only on the architectural or floor plan drawings, as only the site and P-drawings are reviewed by the Plumbing Department.

  1. Show a piping plan, with sizes, for all water, drainage, vent, and gas piping. Additionally, show a detailed isometric drawing for same. List the fixture unit count for all stacks, building drains and building drain branches.
  2. Show all required shutoffs.
  3. Show a detailed drawing of the mechanical room, with emphasis on the incoming water service, including meter and RPZ valve details. The hot water tank and recirculation system - where applicable - must be detailed.
  4. Show an access panel to service the bathroom or whirlpool waste and overflow, for any without easy basement access.
  5. Show all cleanouts as required. Cleanouts may not be installed in any overhead location, which would require service personnel to work off a ladder or temporary platform. Cleanouts shall not be installed in a crawlspace with less than a 4 feet clearance. Such clearance must be direct, with no floor height or overhead obstructions to impede transfer or rodding equipment. Excluding 1- or 2-family dwellings, cleanouts on horizontal runs shall be installed above the flood level of the highest fixture whenever possible.
  6. Floor drains subject to evaporation, or not designed to receive a sufficient flow of water to maintain their seals, shall be equipped with a trap primer device. Such device shall be accessible.
  7. Except for residential use, all plumbing drawings shall list the Occupancy classification, including the anticipated number of patrons and employees expected during periods of peak use.
  8. All building serving food of any kind (which has not been purchased and sold prepackaged) with disposable eating utensils must have a 3-compartment sink and separate hand sink for employee use, in the kitchen area. An adequately-sized grease trap is required for establishments serving any grease- or oil-containing foods, or such used in food preparation.
  9. Oil interceptors, where required, must not tie into the sanitary system until downstream of the house trap.
  10. Elevator pits shall be drained. If sump pumps are installed, the discharge piping must exit beneath the pit floor, and may then rise attached to the pit wall exterior. This must be shown on all drawings with elevators. Oil interception devices will not be required as long as acceptable maintenance is provided. Interception devices are at the discretion of the design professional, if they feel an individual system warrants one.

Sump Pumps shall be indirectly installed into a conductor line. Any tie-in other than this must receive prior permission from the Plumbing Department.