The RFI Trap: How Civil Firms Can Stop "Unbillable Hours" from Eating Their Margin

You designed it correctly. They procured it differently. Now, your team is stuck doing unbillable rework to "make it fit."

There is a specific phone call that every Lead Civil Engineer dreads.

It usually comes three weeks after the "Issued for Construction" set has gone out. You think the project is off your desk. You think your team has moved on to the next billable design.

Then the Project Manager calls from the site: "Hey, so the contractor just took delivery of the stormwater pipes. They ordered Class 2 instead of Class 4 because they thought it was sufficient based on the section view. They are already in the trench. Can you run the numbers and sign off on it?"

In an instant, your "completed" project has bounced back onto your desk.

The "Retrofit" Nightmare

The most frustrating rework in civil engineering isn't fixing a design error; it’s fixing a procurement error.

It is the phenomenon of "Retrofitting Design to Reality."

The contractor has procured the wrong precast pits, or a slightly different aggregate, or a substitute geofabric that was "available immediately." Now, because the material is physically sitting on the job site (or worse, already installed), the pressure is on you to make the design work around the error.

This forces your firm into a lose-lose situation:

1. The "Unbillable" Redesign You have to pull an engineer off a paying job to re-run hydraulic models, re-check structural loads, or re-grade a road alignment to accommodate the slightly different product they bought. Who pays for this time? The contractor argues it was an "ambiguity" in the drawing. The client just wants it solved. Usually, the engineering firm eats the hours to keep the peace.

2. The Liability Shift When you sign off on a procurement deviation to "make it work," you are effectively accepting the liability for a product you didn't specify. You become the insurer of the contractor’s purchasing mistake.

Why "Correct" Drawings Aren't Enough

The root cause of this pain isn't that your design was wrong. It’s that your design was interpreted.

Civil documentation is technical. Procurement is commercial. When a procurement officer at a construction firm looks at your drawings, they aren't looking at the hydraulic nuance; they are looking for a Part Number to put on a Purchase Order.

If there is even a 1% gap in clarity—a note that is slightly open to interpretation, or a spec that is cross-referenced on a different sheet—procurement will default to the cheaper or more available option.

The Cost of "Making it Work"

We often talk about rework in terms of correcting mistakes. But for civil firms, the most expensive rework is validating substitutions.

It disrupts your resource planning. It frustrates your senior engineers who feel like they are cleaning up someone else’s mess. And ultimately, it turns your firm into a "fix-it" shop for the contractor's supply chain, rather than the design authority for the project.

The industry has accepted this back-and-forth as "just part of the job." But when you calculate the hours spent re-justifying a design that was already correct, simply because the wrong truck showed up at the site, the cost to your margin is staggering.

You shouldn't have to redesign your project just because they bought the wrong pipe.