Progressive Design-Build: The Two-Phase Delivery Method That Combines Owner Control With Design-Build Collaboration
Progressive design-build (PDB) has emerged as a significant delivery method for complex construction projects. The approach splits design-build into two phases: pre-construction (design and pricing development) and construction (execution). The owner selects the design-build team based on qualifications, not price, early in the process. Design develops collaboratively. At some point during design, a Guaranteed Maximum Price (GMP) is established, and the team transitions to construction.
PDB combines design-build integration benefits with owner control during design phase. For complex projects where scope is uncertain at outset, PDB often outperforms traditional fixed-price design-build or design-bid-build. This post covers PDB structure and application.
PDB has distinct phases:
PDB phases
- Phase 1 — Pre-construction (qualifications-based selection, collaborative design, pricing development)
- Phase 2 — Construction (execution with established GMP)
- Transition point — GMP establishment, owner decision to proceed
- Owner can off-ramp before construction if needed
Two-phase structure lets owner select team early for collaboration while preserving off-ramp if GMP or scope doesn't fit. Phase 1 is relatively limited commitment; Phase 2 is major commitment. Structure manages owner risk.
Phase 1 selection is qualifications-based:
Selection criteria
- Team experience with similar projects
- Personnel qualifications
- Design firm capabilities
- Construction team capabilities
- Proposed approach
- References and past performance
- Fee proposal for Phase 1 (sometimes)
- Not price on total project
Early selection on qualifications, not price, allows selecting best team before design is complete enough to price. Price-based selection at design-build concept stage produces bidders who may not be best for project. Qualifications-based produces team alignment.
Phase 1 develops design collaboratively:
Collaborative design elements
- Owner involved throughout design
- Design-builder provides constructability input
- Cost estimates at each design stage
- Value engineering during design
- Risk identification and allocation
- Schedule development
- BIM and coordination
Collaborative design phase is PDB's key value. Owner sees design develop, can guide direction, has constructability input from the start. Traditional design-build presents completed design with price; PDB develops both together.
GMP formalizes construction commitment:
GMP in PDB
- Established at specific design completion point
- Typically 60-90% design complete
- Comprehensive price commitment
- Basis of GMP documents
- Allowances for incomplete items
- Contingency for design not complete
- Owner accepts or off-ramps
GMP is contractor's commitment for construction. Establishes price certainty for owner. Owner reviews, negotiates, and decides whether to proceed. If GMP too high or scope wrong, owner can off-ramp — ending the relationship without full construction commitment.
Off-ramps protect owner:
Off-ramp scenarios
- GMP exceeds owner budget
- Scope can't be achieved within budget
- Relationship not working
- Strategic shift
- Exit typically after compensating for Phase 1 work
- Owner retains design (usually)
- Rare but important option
Off-ramps are rare but important. Owner with unacceptable GMP isn't forced to proceed. Paid off team exits; owner restarts or revises approach. Without off-ramp, owner is locked in to whatever GMP emerges.
PDB fits certain projects:
PDB fit factors
- Complex projects with scope uncertainty
- Projects requiring substantial owner input
- Technical complexity benefiting from early contractor input
- Aggressive schedule benefiting from design-build
- Owner wanting control without bidding complete design
- Medium to large projects (small may not justify overhead)
PDB fits complex projects where design-build benefits apply but complete design isn't available or advisable at selection. Simple, well-defined projects may fit traditional approaches. Very large projects may use other delivery. PDB occupies specific niche.
Off-ramp in PDB is rarely exercised but provides critical owner protection. Without it, owner starting PDB is effectively committed to whatever GMP emerges months later. With off-ramp, owner can decline unacceptable GMP. The rare use doesn't diminish the option's value — it's insurance against adverse outcomes.
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PDB vs Traditional Design-Build
Comparison with traditional DB:
PDB vs traditional DB
- PDB selects team earlier
- PDB selects on qualifications not price
- PDB owner has more design control
- PDB price developed collaboratively
- Traditional DB — more price competition
- Traditional DB — less owner involvement during design
- Traditional DB — design risk more fully with DB
Traditional DB puts more design risk on contractor but less owner control. PDB shifts balance — more owner involvement, less price competition at selection. Trade-offs fit different project needs.
Comparison with CMAR:
PDB vs CMAR
- PDB — design-builder holds design
- CMAR — separate designer works for owner
- PDB — single point of responsibility
- CMAR — owner bears design responsibility
- PDB — design-builder can design-build responsibility
- CMAR — owner-designer relationship independent
PDB consolidates design-build responsibility under one entity. CMAR keeps design separate. PDB better fits projects where integrated design-build approach valued; CMAR fits where owner-designer relationship preferred.
PDB contracts have specific structure:
PDB contract structure
- Master design-build agreement
- Phase 1 services agreement (pre-con fee)
- GMP amendment at Phase 2 trigger
- Owner-friendly termination provisions
- Design risk allocation
- Change order procedures
- Standard forms (DBIA, ConsensusDocs)
Standard contracts from DBIA (Design-Build Institute of America) and ConsensusDocs provide PDB framework. Modifications for specific project needs. Legal review essential given the structure's complexity.
Public sector PDB growing:
Public PDB
- State statutes authorizing PDB (growing)
- Federal agencies using PDB
- Transportation authorities common users
- Requires authority under procurement law
- Qualifications-based selection accepted in public sector
- Transparency requirements
Public sector adoption of PDB has grown substantially. Transportation projects especially use PDB. State-specific authority matters — not all jurisdictions authorize. Where authorized, PDB has proven effective for complex public projects.
Progressive design-build combines design-build integration with owner control through two-phase structure. Phase 1 (qualifications-based selection plus collaborative design) develops design and establishes GMP. Phase 2 (construction) executes the committed scope. Off-ramp before Phase 2 protects owner from unacceptable GMP. PDB fits complex projects with scope uncertainty benefiting from early contractor input. Compared to traditional design-build, PDB preserves more owner control but less price competition. Compared to CMAR, PDB consolidates design-build responsibility. Contract structure uses master agreement with Phase 1 services and Phase 2 GMP amendment. Public sector adoption is growing where authorized. For appropriate projects, PDB produces better outcomes than traditional delivery methods by combining integration and owner control. Understanding PDB expands delivery method options.
Written by
Marcus Reyes
Construction Industry Lead
Spent twelve years running AP at a $120M general contractor before joining Covinly. Lives in the world of AIA G702/G703, retainage schedules, and lien waiver deadlines. Writes about the construction-specific workflows that generic AP tools get wrong.
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