, and abbreviated
known as Design-tender
(or "design/tender"), is a
project delivery method in which the agency or owner contracts with
separate entities for each the design
of a project.
Design-bid-build is the traditional method for project delivery and
differs in several substantial aspects from design-build
There are three main sequential phases to the design-bid-build
- The design phase
- The bidding (or tender) phase
- The construction phase
In this phase the owner retains an architect
works) to design and
produce tender documents on which various general contractors
will in turn bid, and
ultimately be utilized to construct the project. For building
projects, the architect will work with the owner to identify the
owners needs, develop a written program documenting those needs and
then produce a conceptual or schematic design. This early design is
then developed, and the architect will usually bring in other
professionals including mechanical
, and plumbing
engineers (MEP engineers), a fire
engineer, structural engineer
sometimes a civil engineer
a landscape architect
complete documents (drawings and specifications). These documents
are then coordinated by the architect and put out for tender to
various general contractors.
Bid (or tender) phase
Bids (tenders) can be "open", in which any qualified bidder may
participate, or "select", in which a limited number of pre-selected
contractors are invited to bid.
The various general contractors
bidding on the project obtain copies of the tender documents, and
then put them out to multiple subcontractors
for bids on sub-components of
the project. Sub-components include items such as the concrete
work, structural steel frame, electrical systems, and landscaping.
Questions may arise during the tender period, and the architect
will typically issue clarifications or addenda. From these
elements, the contractor compiles a complete "tender price" for
submission by the closing date and time. Tender documents can
be based on the quantities of materials in the completed
construction such as in the UK with Bills of
quantities, or the operations needed to build it as in Operational bills.
Once bids are received, the architect typically reviews the bids,
seeks any clarifications required of the bidders, ensures all
documentation is in order (including bonding
if required), and advises the owner
as to the ranking of the bids. If the bids fall in a range
acceptable to the owner, the owner and architect discuss the
suitability of various bidders and their proposals. The owner is
not obligated to accept the lowest bid, and it is customary for
other factors including past performance and quality of other work
to influence the selection process. The project is usually awarded
to the lowest bid by a qualified general contractor.
In the event that all of the bids are in excess of the goals of the
owner, the owner may elect to reject all bids. The following
options become available:
- Abandon the project.
- The architect may revise the design at no cost to the owner,
making the project smaller or more efficient, or reduce features or
elements of the project to bring the cost down. The revised
documents can then be re-tendered.
- The owner may elect to select the lowest qualified bid's
general contractor to join the architectural team to assist with
cost reduction. This process is often referred to as value engineering.
After the project has been awarded, the construction documents may
be updated to incorporate addenda or changes and they are issued
for construction. The necessary approvals (such as the building permit
) must be achieved from all
jurisdictional authorities for the construction process to
In most instances, almost every component of a project is supplied
and installed by sub-contractors. The general contractor often
provides work with its own forces, but it is not uncommon for a
general contractor to limit its role to management of the
construction process and daily activity on a construction site (see
The architect acts as the owner's agent to review the progress of
the work and to issue site instructions, change orders or other
documentation necessary to the construction process.
Potential problems of design-bid-build
- Failure of the design team to be current with construction
costs, and any potential cost increases during the design phase
could cause project delays if the construction documents must be
redone to reduce costs.
- Redesign expense can be disputed should the architect’s
contract not specifically address the issue of revisions required
to reduce costs.
- Development of a "cheaper is better" mentality amongst the
general contractors bidding the project so there is the tendency to
seek out the lowest cost sub-contractors in a given market. In
strong markets, general contractors will be able to be selective
about which projects to bid, but in lean times, the desire for work
usually forces the low bidder of each trade to be selected. This
usually results in increased risk (for the general contractor) but
can also compromise the quality of construction. In the extreme, it
can lead to serious disputes involving quality of the final
product, or bankruptcy of a sub-contractor who was on the brink of
insolvency desperate for work.
- As the general contractor is brought to the team post design,
there is little opportunity for input on effective alternates being
- Pressures may be exerted on the design and construction teams,
which may lead to disputes between the architect and the general
Benefits of design-bid-build
- The design team is impartial and looks out for the interests of
- The design team prepares documents on which all general
contractors place bids. With this in mind, the "cheaper is better"
argument is rendered invalid since the bids are based on complete
documents. Incomplete, incorrect or missed items are usually
discovered and addressed during the bid process.
- Ensures fairness to potential bidders and improves decision
making by the owner by providing a range of potential options. It
also identifies new potential contractors.
- Assists the owner in establishing reasonable prices for the
- Uses competition to improve the efficiency and quality for