Design-Bid-Build: traditional sequential delivery and contract variants

One-line orientation

Design-Bid-Build is the default sequential delivery method — owner hires architect first, then competitively bids construction — and is tested because its contract structure, cost certainty trade-offs, and architect liability limits are foundational ARE knowledge.

Key points

• Sequence: Design (complete CDs) → Bid (competitive or negotiated) → Build. Owner holds separate contracts with the architect and the general contractor.
• Competitive low-bid (traditional lump-sum): Open to any qualified contractor. Owner receives a fixed contract price before construction starts — strong cost certainty. Trade-off: slower (no design/construction overlap), and the adversarial dynamic of price competition can reduce collaboration.
• Cost-plus-fixed-fee:
  • Payment — actual project costs + predetermined fee
  • Benefit — scope flexibility without pressure to protect a lump sum.
  • Risk — owner bears cost overruns and has no locked total price
• Negotiated Select Team: Owner chooses a contractor through negotiation rather than open bidding. Contractor may be brought in during later design phases, enabling early constructability input. Early contractor input may help the schedule and constructability, but negotiated selection does not guarantee higher quality and gives up open price competition.
• Architect’s role and liability boundary: The architect provides design and construction administration; the architect is not liable for the contractor’s means and methods. Construction means/methods — how work is physically executed — remain solely the contractor’s responsibility.

Confusions / comparison

Variant	Bidder pool	Price set when	Owner cost risk	Speed	Collaboration
Lump-sum competitive bid	Open (any qualified contractor)	Before construction (fixed)	Low	Slowest	Low (adversarial)
Cost-plus-fixed-fee	Negotiated / open	Cost is running total; fee fixed	Higher (owner bears overruns)	Moderate	Moderate
Negotiated Select Team	Pre-selected / negotiated	Typically negotiated GMP or lump sum	Moderate	Faster	Higher (early contractor input)

Related

→ Bidding variants (pp-delivery-bidding-variants): open competitive vs invited vs negotiated vs phased/fast-track bid types · Construction Manager roles (pp-delivery-construction-manager): how CM variants modify the DBB structure · Cross-method comparison (pp-delivery-method-comparison): DBB ranked against CMa, CMc, DB, and IPD across owner priorities.