Piping takeoff software for mechanical and plumbing estimators.
A piping takeoff is measured by system, size and material across plans, risers, isometrics and details. Fittings and valves are counted at every change, and hangers follow the spacing in the spec. Software speeds up measuring and fitting generation. The estimator still decides the fitting rules, labor units and what the drawings leave unsaid.
Send one plan set. See what the AI extracts and what it flags for review. No obligation.
- Runs by system, size, material
- Fittings and valves
- Hanger spacing
- Risers and connections
What to capture per run
| Item | Unit | Notes |
|---|---|---|
| Pipe | LF by system, size, material, joining method | Horizontal and vertical (risers are easy to miss on plan views) |
| Fittings | Each by type and size | Counted from isometrics, auto-generated by software, or allowanced |
| Valves | Each by type and size | Plans, details, equipment connection details |
| Hangers and supports | Each, by spacing and size | Spec or code spacing table; rod size by pipe size |
| Insulation | LF by size and thickness | Spec section; often a separate sub |
| Equipment connections | Each | Equipment schedules and connection details |
| Testing, flushing, cleaning | By system | Spec |
Spacing math
Hanger counts come from run length divided by maximum spacing, plus extra supports at changes in direction, valves and equipment. The governing spacing is whatever the project spec cites: MSS SP-58 for many mechanical systems, or the plumbing code's support table for plumbing.
1" standard steel pipe ≈ 7 ft | 2" standard steel ≈ 10 ft | 1" copper tube ≈ 6 ft
(gas, steam and air services allow longer spans)
Example: 400 LF of 2" steel chilled water, 10 ft max spacing
400 ÷ 10 = 40 spans → about 41 hangers on a straight run
+ supports at each elbow, valve and equipment connection (count from plans)
+ trapeze or seismic bracing if the spec calls for it (count separately)
Confirm values against the edition your spec cites before pricing. Insulated pipe also needs shields or saddles at each hanger.
Count or allowance
- Counting: this is the most accurate method when isometrics or detailed plans exist. Count elbows, tees, reducers, unions and flanges by size.
- Software autofitting: tools such as Trimble AutoBid Mechanical and FastEST's FastPIPE generate fittings as you trace runs. Check the rules (elbow vs. bend, reducer placement) against how you actually build.
- Allowances: some estimators carry fittings as a percentage of pipe cost or as fittings per 100 LF from their own history. This is a rule of thumb, so calibrate it to your job cost data and avoid it on fitting-heavy work such as mechanical rooms.
Where piping takeoffs go wrong
- Missed risers. Vertical pipe doesn't show its length on plan; read it from riser diagrams and floor-to-floor heights.
- Mechanical rooms. Their fitting and valve density is far higher than branch runs. Take them off separately.
- Material by size. Specs often change material or joining method above a size break (for example copper below a size, steel above). Split runs at the break.
- Equipment connection details. Each coil or pump connection can carry several valves, a strainer, gauges and flex connectors, and the detail is shown once and applies to every unit.
- Addenda. Re-check sizes and routing on every revision.
Limits
On design-build or schematic drawings, routing and sizes are not final. Price from systems, unit rates or your own design, and state the assumptions.
From plan set to reviewed quantities.
AI-powered, human-approved. Each stage records what ran, what changed and who approved it.
Start with your bid package
Drawings, specs and addenda together: plumbing plans, riser diagrams, the fixture and equipment schedules, isometrics if you have them, and the Division 22 spec sections.
AI proposes quantities
Counts, lengths and areas come back with the source sheet and location attached to every row.
Estimator review
Low-confidence items surface first. Your estimator accepts, corrects or rejects each one.
Map to your assemblies
Approved quantities map to your items, assemblies and estimating assumptions.
Price reviewed rows
Labor units, material pricing and supplier quotes apply only to rows that passed review.
Hand off with evidence
Reviewed quantities move on to your estimate, catalog or quote workflow with the source trail still attached.
Supported files and tasks depend on your trade and implementation. Confirm them in the free sample run.
The AI drafts. Your estimator decides.
Speed is easy to promise. Defensible numbers are the job, so RenderDraw keeps the estimator in control of every quantity that gets priced.
- Source on every row. Each quantity keeps its source sheet, location and reviewer decision.
- Lowest confidence first. The review queue shows the drawing tile with the detection highlighted and the extracted value.
- Uncertain items flagged, not hidden. Anything the AI can't confirm goes to the estimator rather than being guessed.
- Nothing priced before approval. Rows move on to pricing only after they are accepted.
Proposed runs, reviewed by you
RenderDraw's AI takeoff proposes pipe runs by system and size and counts of tagged items, with the source sheet attached to every row. Low-confidence items go to the estimator for review. Fitting rules, hanger spacing, labor units and pricing stay with your estimator and your estimating system. Get a free sample takeoff or book a demo.
Questions estimators ask.
What goes into a piping takeoff?
Pipe by system, size, material and joining method; fittings and valves by type and size; hangers and supports; insulation; equipment connections; and testing and flushing.
How do you count pipe hangers?
Divide run length by the maximum spacing in the governing table (MSS SP-58 or the plumbing code, as the spec cites). Then add supports at elbows, valves and equipment.
Should fittings be counted or allowanced?
Count them when isometrics or detailed plans exist. Use an allowance from your own job history only for branch work, and say so in your assumptions.
What is the most common piping takeoff error?
Missing vertical pipe in risers, followed by under-counting fittings and valves in mechanical rooms and at equipment connections.
Can software generate fittings automatically?
Yes. Mechanical estimating systems such as Trimble AutoBid Mechanical and FastEST FastPIPE generate fittings as runs are traced. Review the rules against your installation practice.
See what the AI reads on your own drawings.
Send one representative plumbing plan set. RenderDraw reviews it and follows up with what the AI extracted and what it flagged for review. Your files remain private while the request is assessed, and there is no obligation.
- Upload plumbing plans, riser diagrams, the fixture and equipment schedules, isometrics if you have them, and the Division 22 spec sections.
- RenderDraw reviews the set and the scope you want tested.
- We follow up with extracted quantities, flagged items and next steps.
Where these numbers come from
We checked this guide against the standards, manufacturer documents and industry references below (last reviewed November 2026). Figures marked as rules of thumb are typical ranges, not requirements; your project documents, local code and your own cost history govern.
- MSS SP-58 overview — third-party summary of the hanger standard
- Pipe support spacing reference — MSS SP-58 spacing values
- Trimble AutoBid Mechanical
- FastEST FastPIPE