Owner Management of Design-Build Project Execution - Design-Build for Water and Wastewater Projects - page 227

3. The design-builder is preparing the final design based on owner concepts and
performance requirements. Certain details may not be familiar to the owner.
For example, pipe routings or maintenance access may be different from other
facilities. Making changes during the design review can result in changes to the
design-builder's overall cost.
There are many ways to approach design issues, and the more involved the owner is
during design development, the more opportunity to provide input in a timely manner.
Establishing a close working relationship with the design-builder as design progresses
allows (1) the designer to better understand the owner's preferences before a particular
approach is selected; and (2) the owner to understand the cost issues that are identified by
the constructor for each particular solution.
There is no question that making a change during the design effort is less expensive
and less disruptive than making that change during construction. Whether the change is
to refocus the design on the conceptual requirements or whether it is to initiate a change
to the scope of the work, it is still better to make the change during design development.
Owners should recognize that the amount of detail that is provided in a DB project
is often less than in traditional delivery. In a traditional project, the designer and owner
include significant detail, protective language, and measures to accommodate any pos-
sible condition that might occur. This approach is used because during design, the con-
tractor for construction and their experience with similar projects are not known.
It is common for design-builders to generate less design documentation for a project
than traditional designers, because design-builders are able to coordinate the exact infor-
mation that is needed to do the work, and they are able to use vendor shop drawings. This
does not mean that less engineering is performed. The detail for certain areas of design
is often performed by vendors or manufacturers for equipment. This is efficient and used
whenever possible to save time and money.
Design changes in design-build projects. A common misconception about DB is that
“there are no changes in the DB process.” This idea was initially promoted to help the
design and construction industries sell DB as an alternative to DBB. It is true that in
DB projects, the owner is shielded from changes that are related to design errors and
the contractor's interpretation of the design. Because the design-builder is a single entity,
errors and interpretive issues associated with detailed design are typically dealt with
internally, without the need for the owner to get involved or to contribute to the solution.
The owner will, however, need to manage changes associated with unforeseen conditions,
deviation from the RFP and/or RFQ documents, force majeure, and other areas where
risk was not transferred.
A concern often expressed about the DB process is that changes to the project are
very expensive when made after the work is contracted. This concern stems mainly from
how changes are handled in the traditional process, and is based on the assumptions that
(1) the design engineer in a traditional process is better able to identify the most cost-
effective approach to the change than the combined expertise of the design-build designer,
constructor, and vendors; (2) the cost assigned to the changed work during the bidding
process will be less than the negotiated cost, assuming that the change was made during
traditional detailed design; and (3) it is not possible to quantify and negotiate a fair and
reasonable change impact with the design-builder once the contract has been awarded.