How it differs from design-bid-build
In design-bid-build, the owner hires an architect, gets finished drawings, then takes bids. In design-build, the owner hires one design-builder for both. Design and pricing happen at the same time. The drawings are not finished when the price is set.
What a sub receives
- The owner's criteria or program, which says what the building must do.
- A narrative that describes each system.
- Early drawings, often schematic.
- Performance requirements in place of a full spec.
- A target budget for the trade, on some jobs.
Two roles for a subcontractor
Some subs only price the work from the design-builder's documents. Others are design-build subs. They design their own system and carry the engineering. Mechanical, electrical, plumbing and fire protection are often handled this way. Know which role you are asked to fill, because the second one carries design responsibility.
How to bid it
- Read the owner's criteria. It governs when the drawings are thin.
- Take off what is drawn.
- List what is not drawn but must be there for the system to work.
- Price both, and keep them apart in your estimate.
- Write a basis of design. Name the products, quantities and performance you priced.
- Write your assumptions as qualifications.
- Expect to reprice as the design develops.
Risk and reward
On a finished set, a missed item is a takeoff error. On a design-build set, the risk is the item no one has drawn yet. Your price can be held to the owner's criteria, not only to the early drawings. A clear basis of design is your protection. It shows what your price covered when the design changes.
The sub is chosen earlier and on more than price. Your product knowledge shapes the design. There are fewer bidders. The cost is more estimating time and more risk.
Bidding and estimating · Updated 11 Nov 2026