Status of Design-Build in the US Water and Wastewater Sectors - Design-Build for Water and Wastewater Projects - page 27

“D esign-build limits the

•Time and cost savings . Design-
build delivery has proven to be
particularly effective for water and
wastewater projects with demand-
ing schedules by saving time in
the overall project delivery dura-
tion. Time is saved in the execu-
tion through some overlap in design
and construction because construc-
tion can often begin before the total
design is complete. In addition,
there is the potential to reduce time
and costs through the efficiencies
that can be gained through integra-
tion of design and construction.
•Earlyknowledgeoftotalcosts. Design-build water and wastewater projects are
typically lump sum or guaranteed maximum price (GMP), which includes design
and construction. In a competitive procurement process, a firm lump-sum price is
provided in response to the Request for Proposals (RFP). In a qualifications-based
selection (QBS) negotiated DB process, a firm lump sum or GMP is typically estab-
lished at approximately 50 to 60 percent completion of the design.
The WDBC conducted a telephone survey of over 20 municipal owners who opted to
use DB delivery for water and/or wastewater projects (WDBC 2008). Table 3-1 displays
their reasons for doing so on a five-point scale, where five was a primary reason, three was
a secondary reason, and one was not considered to be a reason. Single-point accountability
and speed of delivery ranked the highest.
When asked an open-ended question on the most beneficial attributes of DB deliv-
ery, respondents identified single-point accountability and speed of delivery more than
twice as often as any other attribute. The third most beneficial attribute cited was the abil-
ity to choose builders on the basis of other criteria, in addition to price.

unknown of having builders come in and

low bid resulting in construction and opera-

tions problems. Design-build is not the cheap-

est, but you do not want a builder in there

who does not know what they are doing

resulting in problems later on.”

—Drew Goins, Assistant Director,
Water Production, Augusta, Georgia

Table 3-1. Reasons why owners use design-build
Decision Factors Relative Importance*

Single-point accountability 4.3

Speed of delivery (Time savings) 4.3

Having the builder involved in the design process 4.2

Construction quality 4.0

Price certainty 4.0

Fewer change orders 3.9

Flexibility 3.9

Lower costs 2.9

*5 = primary reason; 3 = secondary reason, 1 = not a reason
Source: WDBC 2008.