Benefits and Challenges of Design-Build - Design-Build for Water and Wastewater Projects - page 10

method is characterized by separate contracts between the owner and the designer and
the owner and the construction contractor (Figure 2-1).

Design-Build Structure Design-Bid-Build Structure

Owner Owner

Single
Contract

Design-Builder Designer Contractor

Figure 2-1. Single point of responsibility for DB compared to DBB

In a 2008 survey of owners who had used DB for their water or wastewater projects,
the single point of responsibility was the top reason given for using DB (WDBC 2008).
In this same survey, the owners also reported a high degree of satisfaction with respect to
their expectations of the single point of responsibility associated with their specific DB
projects.
For an owner, having a single design-builder under contract can result in several
benefits (ASCE 1992):
•Improved accountability and reduced administrative tasks associated with tracking
multiple contracts
•No disagreements over project responsibility between the designer and the con-
struction contractor
•Fewer change orders by eliminating those associated with the design/construction
interface (e.g., design errors and omissions)
•Increased protection from liability for design defects or omissions
•Rapid reaction to scope changes because designers and constructors are working
together
All of these benefits result from the fact that both the designers and constructors are
part of the same team, which means that the owner has a single point of responsibility for
project delivery.

Innovation

The potential for increased innovation on DB projects is a result of having both the
designer and the constructor collaborating together early in the project, as is the case for
projects that are procured with a best-value or price-based approach (see chapter 7). For
these types of DB projects, the design-builder is formed during the procurement phase,
which allows both parties to work closely together to create innovative design and con-
struction solutions as part of the proposal. Creating a competitive procurement environ-
ment can increase the potential for innovation as design-builders compete to develop the
proposal with the best value for the owner. The potential for innovation continues after
contract award as the design-builder has the opportunity to identify innovative designs
and construction procedures that may result in schedule, cost, and quality benefits.