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AI drafting for plumbing

AI Drafting for Plumbing Engineering

Plumbing sheets repeat the same work in three places: the plan, the riser, and the fixture unit tally that sizes both. Nomic drafts domestic water, sanitary and vent, storm, and gas plans in CAD, draws the risers, totals fixture units from the architectural fixture layout, and checks the result against the IPC or UPC and the local amendments you attach.

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Last reviewed: November 2026

You send

  • Architectural plans and enlarged restroom plans
  • Plumbing fixture schedule and cutsheets
  • Your engineer's sizing criteria, water pressure, and rainfall rate
  • Your CAD standards and past plumbing sheets as precedent
  • The IPC or UPC edition and local amendments

Nomic hands back

  • Domestic water, sanitary and vent, storm, and gas plans as DWG files
  • Waste, vent, and water riser diagrams
  • Fixture unit tallies and fixture schedules in Excel and on the sheet
  • Revision clouds on every change and a list of open questions
1234567ABCAMENITY501UNIT502UNIT503UNIT504UNIT505UNIT506UNIT507UNIT508AMENITY509UNIT510UNIT511STAIRS24" SS-1CO4" SAN @ 1/8"/FT2" V27'-3"27'-0"27'-3"27'-3"27'-0"27'-3"94'-8"1APLUMBING PLANSCALE: 1/8" = 1'-0"N1234CONSULTING ENGINEERSREVISIONS1ISSUED FOR REVIEWPROJECTCEDAR LOFTSSCALE1/8" = 1'-0"DATE02/10/2026KEY PLANSHEET TITLEPLUMBING PLANSHEET NUMBERP-101

On the sheet

Plumbing Plan, annotated

A plumbing plan with fixtures, waste and vent piping, and domestic water routed to each group.

  1. 1Water closet and lavatory on the wet wall
  2. 2Sanitary main sloped to the stack
  3. 3Vent line tied to each fixture
  4. 4Stack and cleanout

The problem

One restroom change ripples through every plumbing sheet

When the architect adds two lavatories and a mop sink to a core restroom, the plumbing designer redraws the waste and vent on the floor plan, updates the stack on the riser, recounts drainage fixture units for the branch and the building drain, recounts water supply fixture units for the hot and cold mains, and checks that the trap arms still fit the vent distance table. On a six-story building with stacked cores, that is every floor.

The misses are predictable: a trap arm that runs 7 ft on a 1-1/2 in. line, a vent through the roof that lands next to an air handler intake, a riser that still shows last month's pipe sizes, a secondary roof drain left off because the parapet was added late, or a city amendment that requires backwater valves nobody pulled into the set.

01 / Layout

Plans and risers drawn from the fixture layout

Attach the architectural plans and enlarged restroom plans and tell Nomic which systems to draw. Nomic connects each fixture to waste, vent, hot, and cold water on your layers, slopes and sizes lines to the criteria your engineer sets, and draws the matching riser diagram from the same piping.

  • Sanitary, vent, and domestic water plans connected fixture by fixture
  • Storm drainage with primary and secondary roof drains
  • Gas piping with appliance loads and pipe lengths noted
02 / Fixture units

Fixture units tallied from the drawing, not from memory

Nomic counts every fixture it connected and assigns drainage and water supply fixture units from the plumbing code the project follows. Your engineer sees the tally per branch, stack, and main, and sizes from it or has Nomic size to the tables they name.

  • Drainage fixture units per branch, stack, and building drain
  • Water supply fixture units for hot and cold mains
  • Fixtures on the architectural plan but not on the plumbing plan flagged
03 / Check

Checked against the plumbing code and local amendments

Nomic checks its own plans and risers against the IPC or UPC edition you name, plus the city or state amendments you attach, and against the mechanical roof plan. Each finding cites the section, so your engineer can confirm it with less manual work.

  • Trap arm lengths checked against the vent distance table
  • Vent terminals checked against doors, windows, and air intakes
  • Minimum fixture counts checked for the occupancy

Checked against

The code and documents behind every sheet

Name the editions the project is designed to and Nomic checks its own drawing against them before handing it back. Your engineer or architect of record makes the final call and stamps the set.

  • International Plumbing Code or Uniform Plumbing Code
  • International Fuel Gas Code or NFPA 54
  • State and city plumbing amendments
  • Mechanical roof plan for vent and intake separation
  • Your firm CAD standards

How it works

From a sentence to a stamped set

  1. Step 1

    Ask for the drawing

    Say what the sheet needs to show and attach the backgrounds, markups, cutsheets, or photos. A sentence is enough to start.

  2. Step 2

    Nomic drafts it in CAD

    Nomic works in CAD on its own computer, on your layers and blocks, following how your firm drew the same thing before. It saves real DWG files to the project.

  3. Step 3

    Nomic checks its own work

    The drawing is checked against the code editions you name and the source documents. Everything Nomic drew is clouded, and open questions are listed.

  4. Step 4

    Your team reviews and stamps

    Your engineers and architects review the clouded changes, make the final call, and issue the set under their own stamp.

FAQ

Frequently asked questions

Yes. Nomic works in CAD on its own computer and saves DWG files for domestic water, sanitary and vent, storm, and gas plans, plus riser diagrams. It connects each fixture from the architectural plans and draws on your layers and symbols.

Nomic tallies drainage and water supply fixture units from the fixtures it drew, using the tables in the code your project follows. It can size pipe to the tables and criteria your engineer names, such as available pressure and developed length, and your engineer reviews and makes the final call on every size.

Yes. Name the code, such as IPC 2021 or UPC 2024, and attach the state or city amendments. Nomic uses those fixture unit values and requirements and cites the code section or amendment behind each finding.

No. Nomic works in CAD on its own computer and saves DWG files you open in AutoCAD or any DWG editor. For Revit projects, Nomic delivers DWGs and a change list your modeler links into the model.

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AI Drafting for Plumbing: Sanitary, Water, and Riser DWGs | Nomic