How a gap happens
The drawings and the spec divide the work by section, not by subcontractor. Some items sit between two sections. Each sub reads its own section and assumes the other one covers the item. The GC finds the hole after the contracts are signed.
Common gaps
- Power to equipment. The equipment sub excludes wiring. The electrician did not see the motor on the equipment sheet.
- Blocking and backing in walls for wall-mounted items.
- Structural supports above the ceiling for hung equipment.
- Floor sleeves and anchors set in the slab.
- Final connections to owner furnished equipment.
- Firestopping at penetrations.
- Access panels.
- Controls and low-voltage wiring between two trades.
Who pays for a gap
It depends on the contracts. The GC usually owes the whole job to the owner. The GC then looks at each subcontract to find who must do the work. A sub with a clear written exclusion stands in a strong place. A sub with a vague scope letter does not.
How a sub avoids being the gap
- Read the related sections your spec section refers to.
- Look at other disciplines' sheets for your items. Check structural, electrical and food service sheets.
- Write down every item you decide is not yours.
- Put those items in your exclusions, with the section or sheet.
- Ask the GC before the bid when an item has no clear owner.
The opposite problem
Scope overlap is the reverse. Two subs carry the same item, and the owner's price is higher than it needs to be. GCs look for both problems when they level bids.
Takeoff Tool flags items that are spec'd but not drawn, drawn but not spec'd, or marked by others. Those flags are where gaps hide.
Bidding and estimating · Updated 11 Nov 2026