A utility subcontractor doesn't price one job off a plan set. It prices two.
The wet side is storm, sanitary sewer, and water. The dry side is electrical and communications conduit and ductbank. Both come off the same civil drawings, both share trenches, and both have to be counted before the bid is due. The estimator traces every run, counts every structure and fitting, and builds the list by hand.
Here is what each side involves, and where the money leaks.
What goes into a wet utilities takeoff
A wet utilities scope starts with linear feet of pipe, separated by utility, size, and material. Water main is counted apart from sanitary sewer, and both are counted apart from storm. On top of the footage sit the fittings and bends, counted by type and degree, plus hydrants, gate valves, manholes, vaults, meters, and plugs.
The quantities live on different sheets. Run lengths come off the plan view. Depths, inverts, and grade changes come off the profile sheets. Fittings and appurtenances show up in callouts, details, and notes. Trench length, width, and depth follow from all of it, and trench width requirements vary by jurisdiction.
Standard estimating guidance for underground work says to follow each pipe from its starting point to its ending point, and to start with the plans, not the job site. That advice is right. It is also slow.
What goes into a dry utilities takeoff
Dry utilities means conduit and ductbank for electrical power and communications. The estimator counts conduit runs by size, type, and number of ways, traced from source to termination. Handholes, pull boxes, manholes, and vaults each get counted, along with transformer and switchgear pads.
Ductbank adds a wrinkle. The length comes from the plan, but what's inside each run comes from a typical section detail: how many conduits, how they're arranged and spaced, and how much concrete encases them. That one detail may apply to a dozen runs. Concrete volume, spacers (a common rule of thumb is one per five feet of conduit), bedding, and backfill all follow from the section and the length.
So the estimator has to keep two things straight across the whole set: which run uses which section, and what that section means for materials.
Where site utility bids lose margin
Missed fittings are the classic problem. Estimating guidance for underground utilities names a single overlooked fitting as a common cause of budget overruns. A tee or bend priced at zero looks like nothing on the bid. It shows up after the trench is open.
Lumping utilities together hides detail. Pricing water, sewer, and storm as one bucket is faster, but the number gets less accurate. Separating them means more counting, so the pressure to skip it is constant.
The dry side has its own version. If the wrong section detail gets applied to a run, the mistake repeats across every foot of that run: too little conduit, too little concrete, or too many spacers.
Crossings and existing conditions add risk. Wet and dry scopes cross each other and often share trench. As-builts for existing utilities are useful, but depths are often missing or inaccurate, so conflicts turn up in the field. Unclear lines between trades around locating, potholing, backfill, and restoration add rework and change orders.
Addenda hit everyone. A revised profile or an added hydrant changes quantities on sheets you already finished, and tracking the delta by hand is where errors sneak back in.
Underneath all of it is time. Every hour spent tracing pipe is an hour not spent on scope review, pricing, or the next bid. For most utility contractors, bid volume is limited by how fast the estimating team can take off, not by how much work is out there.
Five habits that tighten a takeoff
Trace each utility as its own system from start to end before moving to the next. Count structures first, then use their IDs as anchors when you measure the runs between them. Cross-check plan lengths against profile stationing to catch drawing conflicts early. Keep a running fitting list per run and reconcile it against the details sheet before you price. Log addenda changes by sheet, so a revision doesn't reset the whole takeoff.
None of this is new. All of it takes time.
Where AI takeoff fits
AI takeoff doesn't replace the estimator's judgment on scope, risk, or price. It takes over the finding and counting: reading the plan set, measuring runs, counting structures, and keeping a record of which sheet each quantity came from. The estimator reviews, corrects, and approves.
That is the shift RenderDraw is building toward for site civil. The estimator moves from data entry to review, and the same team can look at more bids. Our next post walks through how that works on a civil plan set.
FAQ
What is a wet utilities takeoff? It is the process of measuring and counting the water, sanitary sewer, and storm scope on a civil plan set. That includes pipe footage by size and material, fittings and bends, valves, hydrants, and structures like manholes.
What is a dry utilities takeoff? It is the same process for electrical and communications scopes. It covers conduit runs, ductbank sections and encasement, handholes, pull boxes, vaults, and equipment pads.
Why is ductbank harder to take off than a single conduit run? The length is on the plan, but the makeup of each run (conduit count, spacing, encasement) comes from a typical section detail that applies to many runs. The estimator has to connect each run to the right detail.
How long does a utility takeoff take? It depends on the size of the plan set and the scope. Any time figures should come from your own history, since they vary widely by project.
Want to see it on your own plans?
If you estimate site utilities, send us a completed plan set and we'll show you what a first-pass takeoff looks like. [CTA link: renderdraw.com contact or demo page]
Sources: SMA Estimating, "How Do You Estimate Underground Utilities?"; Verde Terre Contracting, "Underground Utility Construction 101"; Construction Monkey duct bank calculator (spacer rule of thumb).
Book a call -> https://renderdraw.com/contact