Design-build

Design-build (or design/build, and abbreviated D-B or D/B accordingly) is a construction project delivery system where, in contrast to "design-bid-build" (or "design-tender"), the design and construction aspects are contracted for with a single entity known as the design-builder or design-build contractor. The design-builder is usually the general contractor, but in many cases it is also the design professional (architect or engineer). This system is used to minimize the project risk for an owner and to reduce the delivery schedule by overlapping the design phase and construction phase of a project. Where the design-builder is the contractor, the design professionals are typically retained directly by the contractor. This is one of the oldest forms of construction since developing from the "Master Builder" approach.

History

The design/build delivery system often cites the original "Master Builder" model used to build most pre-modern projects. Under the Master Builder approach, a central figure of the architect held total project accountability. From inception to completion, the master builder was the key organizational figure and strictly liable to the owner for defects, delays, and losses. The design/build system is a return to some of the fundamentals of the Master Builder approach.

Overview of process

Design-build focuses on combining the design, permit, and construction schedules in order to streamline the traditional design-bid-build environment. This does not shorten the time it takes to complete the individual tasks of creating construction documents (working drawings and specifications), acquiring building and other permits, or actually constructing the building. Instead, a design-build firm will strive to bring together design and construction professionals in a collaborative environment to complete these tasks at the same time.

Typically the hallmark of a Design/Build project is that one organization is responsible for both design and construction of the project. If this organization is a contractor, the process is known as "Contractor-led Design-Build". If the organization is a design firm, the process is known as "Design-led Design-Build". In either case, the organization employed by the owner rarely handles both aspects of design and construction in-house. In fact, the organization often subcontracts with on-site personnel (if design-led) as well as architects and engineers (if contractor-led).

Potential problems of Design-Build

Cost estimating for a design-build project is sometimes difficult because design documents are often preliminary and may change over the course of the project. As a result, design-build contracts are often written to allow for unexpected situations without penalizing either the Design-Builder or the owner. Several organizations (such as the Design Build Institute of America) provide standardized form contracts for design-builders to use, but it is not unusual for the design-builder to provide its own contractual documents.

This uncertainty requires the owner to rely a great deal on the integrity, acumen, and competence of the design-builder. As the certainty of estimates decreases, the opinion of the construction professionals of the Design-Build firm must be trustworthy, accurate, and reasonably verifiable in order to minimize risk.

Additionally, the brevity of the process restricts regulatory review efforts to a potentially cursory overview. Projects may be designed as they are built, thus providing those with the responsibility of oversight little to no time at all to review completed plans and specifications. Projects completed before they may be reviewed can be forced into costly change orders to bring the project into compliance with regulatory requirements.

Benefits of Design-Build

It is important to note that the design-build method, while not focused on saving the owner construction costs, nonetheless often saves the owner money on the overall project. The combined effects of carrying a construction loan (which typically carries a higher interest rate than permanent financing) and an earlier useful on-line date usually yields considerable overall profitability to the project and may make seemingly unfeasible projects into genuine opportunities.

The compression is an important aspect of the implementation of this system. Other attributes include:
* increased accountability by the service provider,
* single source project delivery, and
* a value based project feedback system

Accountability

Rather than a parcelized level of responsibility of the classic design-bid-build, design-build provides an integrated solution for the owner or client. This moves projects away from the "finger-pointing" that is often commonplace in contemporary construction projects, and allows the owner to look to one entity with any questions or concerns.

Single Source

Instead of having several contractors and consultants, an owner has just one entity to deal with. Design revisions, project feedback, budgeting, permitting, construction issues, change orders, and billing can all be routed through the design-build firm. This single point of contact allows a certain degree of flexibility for the owner. Most design-builders will leverage that flexibility for the owner's benefit by continually refining the construction program to maximize the owner's value at the completion of the project.

Value-based project feedback

Typically, in order for a contractor to bid on a project, very specific details relating to the methods and materials must be given to avoid any ambiguity and to make an "apples to apples" comparison of bids. In a design-build context, the owner, the owner's other consultants, and the design-builder can work together to determine what methods and materials will maximize the owner's value. In instances where marginally more expensive materials, designs, or construction methods might yield a higher return on investment for the owner than those of lower cost, the owner is free to adjust the project's program without having to re-bid the entire project.

ee also

* Architectural services
* Architectural engineering
* Civil engineering
* Construction bidding
* Construction engineering
* Construction software
* Cost overrun
* Design-bid-build
* Construction Management
* Joint Contracts Tribunal
* Submittals (construction)
* Shop drawing
* Public-private partnership

External links

* [http://www.dbia.org The Design/Build Institute of America]
* [http://www.stuorg.iastate.edu/dbia/ Iowa State University Student Chapter of DBIA]
* [http://www.pmg-idaho.com Project Management Group Inc.]