Overlap detection is the process of identifying instances where two or more subcontractors’ scopes both claim responsibility for the same piece of work, the mirror image of a scope gap, where nobody claims a piece of work at all. Both conditions cause real problems, but overlap tends to cost money directly rather than causing a field delay first.
A classic overlap: a drywall subcontractor’s proposal includes patching around all wall penetrations, while the mechanical, electrical, and plumbing subs each also include minor patching in their own proposals for penetrations they create. If nobody catches this during the buyout, the GC ends up paying for the same patching work multiple times across different trade contracts, without anyone necessarily noticing until someone eventually audits the buyout numbers against the actual scope.
Detecting overlap requires the same kind of cross-referencing discipline as detecting a gap, comparing every relevant trade’s proposal against every other trade’s proposal in the same cluster, not just checking each one individually against the drawings. The difference is what you’re looking for: a gap shows up as zero claims on an item; overlap shows up as two or more claims on the same item.
Overlap is arguably easier to miss than a gap in practice, since a gap eventually announces itself in the field when nobody’s crew shows up to do the work, while overlap can go entirely undetected for the life of the project if nobody specifically audits for it; the redundant cost simply gets absorbed into the project budget without ever surfacing as a visible problem to flag.
A useful discipline for catching overlap without dedicated software: building a simple matrix listing every scope item across a given trade cluster’s CSI divisions and marking which proposal claims each one during buyout review. Any item with two or more claims flags a likely overlap worth resolving before signature; the same exercise is used to catch gaps, just watching for the opposite pattern: too many claims on an item rather than none at all.
Overlap isn’t always a pure waste; occasionally, a modest amount of deliberate redundancy in scope, clearly documented as intentional, serves as a reasonable safeguard against a critical item falling through entirely. What matters is that any such redundancy is a conscious choice rather than an accidental byproduct nobody noticed during the buyout, since unintentional overlap simply costs money without providing any of that deliberate safeguard value.
