A per-project aggregate is an endorsement on your commercial general liability policy that gives you a separate aggregate limit for each project you work on, rather than sharing a single aggregate across all your jobs for the policy year. Understanding this distinction can mean the difference between maintaining coverage on a critical project and being left exposed after a single large claim drains your limits.
Standard Aggregate vs. Per-Project Aggregate
A standard CGL policy with $1,000,000 per-occurrence and $2,000,000 general aggregate means you have $2 million total available for all claims during the policy period. If you are running five roofing projects simultaneously and a $1.5 million completed operations claim hits on Project A, you have only $500,000 of aggregate remaining for Projects B through E for the rest of the year. One bad claim on one job compromises every other job you are working.
With a per-project aggregate endorsement (ISO form CG 25 03), each project gets its own $2,000,000 aggregate. That same $1.5 million claim on Project A leaves your other projects fully covered at their own $2 million aggregate. The per-occurrence limit of $1,000,000 still applies per claim on each project, but the aggregate resets for every scheduled project.
When General Contractors Require It
Most commercial general contractors with projects valued above $1 million require roofing subcontractors to carry a per-project aggregate. This is standard language in AIA A401 subcontract agreements and ConsensusDocs contracts. The GC's risk manager wants assurance that claims on your other jobs will not erode the limits protecting their project. If your certificate of insurance shows a standard aggregate instead of per-project, expect the GC to reject it.
What It Costs
A per-project aggregate endorsement typically adds 5% to 15% to your GL premium. On a policy costing $15,000 annually, expect an additional $750 to $2,250. The cost varies by carrier and your claims history. Some specialty roofing markets include it automatically on commercial contractor policies because they know GCs require it. If your current carrier charges more than 15%, shop the endorsement — you are likely overpaying.
When You Absolutely Need It
You need a per-project aggregate if you perform commercial roofing work for general contractors, bid on public or government projects, work on projects with contract values above $500,000, or maintain multiple active job sites simultaneously. If you are a residential-only contractor running one job at a time, a standard aggregate is usually sufficient. But the moment you take on commercial work or run multiple crews on concurrent projects, the per-project endorsement becomes essential.
How to Verify It on Your Policy
Look at your CGL declarations page. Under "General Aggregate Limit," it should state "Per Project" or reference endorsement CG 25 03 or CG 25 04. If it says "Per Policy" or "Per Location," you do not have per-project coverage. Ask your broker to confirm which ISO form is attached and whether it applies to both ongoing operations and completed operations. Some carriers issue the endorsement for ongoing operations only, which leaves a gap on completed work.
For roofing contractors juggling multiple commercial projects, the per-project aggregate is not optional — it is a contractual requirement that protects both your clients and your ability to keep bidding work after a loss event.