How Excess Liability Stacks on Top of GL

THE TOWER, NOT A SEPARATE POLICY

Insurance people call this structure a “tower” for a reason: picture your coverage as floors stacked on top of each other, not a pile of unrelated policies. The ground floor is your underlying coverage, General Liability, Commercial Auto, and the Employer’s Liability piece of Workers’ Comp. Each carries its own per-occurrence and aggregate limit. The excess policy is the next floor up, and it doesn’t activate until the floor below it is completely exhausted.

That’s the key mechanic: an excess policy has no first-dollar responsibility. If your GL is written at $1 million per occurrence and a claim settles for $600,000, your excess policy never gets touched, the underlying GL absorbs the whole thing. The excess layer exists specifically for the claim that blows past that $1 million mark, a serious utility strike, a cave-in with lasting injury, a multi-vehicle accident involving your fleet.

HOW THE LIMITS ACTUALLY ADD UP

When an excess policy sits above a GL policy, the math is straightforward addition. A $1 million GL limit plus a $4 million excess policy gives you $5 million in total available protection for a covered GL claim. Add a second layer, or a larger single layer, and the number grows the same way. What doesn’t change is the underlying policy’s terms, a following-form excess policy (the structure most excavation contractors should use) simply extends the dollar amount available under those same terms, it doesn’t rewrite what’s covered.

This is also why excess coverage is priced the way it is: because it only responds after a large, usually rare, loss, the premium per dollar of coverage tends to drop the higher up the tower you go. Buying the first $1 million of excess costs more per dollar than buying the fifth million, which is part of why insurers structure excess towers in layers rather than one giant policy.

WHY EXCAVATION CONTRACTORS FEEL THIS MORE THAN OTHER TRADES

A framing crew’s worst-case GL claim rarely threatens to exceed a $1 million limit. An excavation crew’s worst-case claim, a struck gas main affecting a city block, a trench collapse with serious injury, realistically can. According to the Insurance Information Institute, a severe liability lawsuit can carry enough financial weight on its own to threaten a business that’s underinsured at the top of its program. That’s exactly the scenario the excess layer is built to absorb, and it’s why GCs and municipal owners on larger excavation contracts ask for it as a matter of course, not as an upsell.

Back to the Excess and Umbrella Insurance for Excavation Contractors hub. Related reading: When GCs Require Higher Limits Than Your Base Policy and Following Form vs Standalone Excess Policies.