Beyond General Liability: How to Spot Contractors’ Hidden Design Risk

• August 17, 2026

By John Immordino

Most agents who work with contractors are very comfortable placing general liability coverage. It’s the foundation of almost every contractor account as it handles the core exposures tied to bodily injury and property damage.

But there’s a growing area of risk that general liability simply wasn’t designed to cover, and it’s starting to catch more contractors off guard. That exposure is design responsibility.

The challenge is that many contractors don’t think of themselves as taking on design risks because they’re not architects or engineers. But the reality is that the way projects are delivered today has blurred that line.

Building vs. Designing

Contractors are increasingly being asked to do more than just build. They’re selecting materials that must meet specific performance standards, providing shop drawings that include design elements, hiring specialty engineers and making changes to plans to save time or reduce costs. These decisions may feel like part of the normal construction process, but they often influence how a system functions and not just how it’s installed. That distinction is what creates the gap.

General liability policies are designed to respond when something is built incorrectly and causes bodily injury or property damage. Those policies typically exclude issues related to professional services, such as design errors, engineering decisions or performance failures.

So, when a loss stems from how something was designed rather than how it was installed, the general liability policy often won’t respond.

A common example is a building envelope or a window system that begins to leak. At first glance, it looks like a construction defect, but after review, the issue turns out to be related to how the system was designed; maybe the drainage wasn’t adequate or the specifications didn’t account for certain conditions.

Even if the contractor installed everything correctly, they can still be pulled into the claim because of their role in selecting, coordinating or taking responsibility for that system. And when the claim is tendered to the general liability carrier, it may be denied as a professional services issue.

These situations are becoming more common. Project delivery methods, such as design-build, continue to grow and owners are increasingly shifting responsibility downstream to contractors. At the same time, faster project timelines and tighter budgets are leading to decisions to streamline costs, as well as greater reliance on specialty trades to complete design components. All of this adds up to contractors taking on more professional risks, whether they realize it or not.

For agents, the key is recognizing when a contractor has crossed that line. If an insured is involved in design-build work, delegated design—such as trusses, HVAC or fire protection systems—making material or system selections based on performance, or hiring engineers to support their scope, there’s a strong chance they have a professional liability exposure.

One of the simplest ways to frame this for clients is: “Your general liability policy covers you if you build something wrong. Contractors E&O covers you if something was designed wrong.” That distinction tends to resonate quickly.

Another helpful way to think about it is side by side:

Coverage	General Liability (GL)	Contractors E&O
What it covers	Bodily injury and property damage	Financial loss from design errors
Installation mistakes	Typically covered	Not intended
Design mistakes	Usually excluded	Typically covered
Shop drawing errors	Usually excluded	Typically covered
Hiring an engineer	Usually limited or excluded	Vicarious coverage often included
Fixing a problem early	Usually no coverage	Sometimes covered (rectification)

At the end of the day, many contractors already have this exposure built into their operations. They just haven’t matched it with the right coverage. For agents, this creates a meaningful opportunity not just to round out an account but also to help clients avoid a type of claim that can be both unexpected and financially significant.

John Immordino is senior vice president, professional liability at Arlington Roe.