Research finds design-build delivery continues to make the grade

New Design/Build Institute of America-backed research finds that the design-build (DB) method delivers projects faster and with greater cost and schedule performance than Construction Management at Risk (CMR) and traditional Design-Bid-Build (DBB) alternatives.

“As our nation continues to struggle with crumbling infrastructure and budgets stretched thin, it’s no surprise that most states have embraced design-build as a better way to deliver projects vital to economic growth,” says DBIA Executive Director Lisa Washington. “Whether it’s a billion-dollar airport or small community library … design-build is clearly a better way to build.”

Authors of the “Revisiting Project Delivery Performance — New benchmarks for unit cost, delivery speed, cost and schedule reliability” conclude that DB projects:

  • Cost 1.9 percent and 0.3 percent less per square foot, respectively, than those using CMR and DBB;
  • Average 2.4 percent and 3.8 percent less cost growth than comparably scoped CMR and DBB work, respectively;
  • Perform best in terms of schedule growth, exhibiting respective levels 3.9 percent and 1.7 percent below those of CMR and DBB;
  • Are 13 percent and 36 percent faster than CMR and DBB, respectively, during the construction phase; and,
  • From design through completion, are delivered 61 percent and 102 percent faster, respectively, than CMR and DBB.

The Charles Pankow Foundation and Construction Industry Institute (CII) supported the research, which factored data from 80 DB, 79 CMR and 53 DBB projects—131 public and 81 private. “Revisiting Project Delivery” findings build on “A Comparison of U.S. Project Delivery Systems,” a 1998 study benchmarking the three methods. An eight-page research summary, authored by University of Colorado, Boulder Professor Keith Molenaar, PhD and University of Florida, M.E. Rinker, Sr. School of Construction Management Assistant Professor Bryan Franz, PhD is posted at www.dbia.org.

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Reseachers found improving median rates for Construction Manager at Risk and Design-Bid-Build methods in the latest versus the initial survey. Design-Build’s lower median monthly building square footage, by contrast, reflects a different project mix between the two surveys: Among 1998 DB contracts, 28 percent were Light Industrial, including warehouses, parking structures and other facilities of low complexity and rapid construction potential. In the 2018 survey, only 9 percent of the DB projects were Light Industrial.
SOURCE: “Revisiting Project Delivery Performance,” CII/CPA 2018