Design-Build (DB) Construction is a project delivery system used in the construction industry. It is a method to deliver a project in which the design and construction services are contracted by a single entity known as the Design–Builder or Design–Build Contractor.

In contrast to “Plan & Spec”, Design–Build relies on a single point of responsibility contract and is used to minimize risks for the project Owner and to reduce the delivery schedule by overlapping the design phase and construction phase of a project. This type of project delivery method, with its single point of responsibility, provides a great amount of safety for building Owners and developers because the DB Contractor is responsible for the work of the project. AT Mechanical is typically subcontracted to the main DB Contractor.

Design-Build Construction is not suitable for every type of project, but it is growing in popularity. A 2011 study analyzing the DB project delivery method in the United States shows that Design-Build was used on more than 40 percent of non-residential construction projects in 2010, a ten percent increase since 2005. The study was commissioned by the Design-Build Institute of America (DBIA) and was completed by RSMeans Reed Construction Data Market Intelligence.

In Design-Build Construction, the Owner contracts with one entity for the design and construction.

The “traditional” Plans and Spec’s approach for construction projects consists of the appointment of a Designer on one side, and the appointment of a Contractor on the other side. The DB procurement route changes the traditional sequence of work. Because of this and the rise of the Design–Build project delivery method, DB has threatened the traditional hierarchies and knowledge depositories of the design and construction industry. As a result, a debate has emerged over the value of design–build as a method of project delivery.

Proponents of the “Plans and Spec’s” method claim

1) The DB approach limits the client’s involvement in the design.

2) Contractors often make design decisions outside their area of expertise.

3) A Designer - rather than a Contractor Professional - is a better advocate for the client/owner.

4) By having Designers and Contractors representing different perspectives and remaining in their separate spheres of influences, Designers and Builders ultimately create better buildings.

5) The Design–Build procedure is poorly adapted to projects that require a complex and elaborated design for aesthetic or technical purposes.

We agree with many of the points made above, and as always “the Devil is in the Details.” You cannot say unequivocally that one system is better than the other. Each system has its place, and a lot of the decision depends on the quality of the Designers and the quality of the Contractors. The choice is ultimately of the Client/Owner(s).

Proper Design-Build Construction is only executed by Engineer-Contractors who are passionate about design, believe in what they are doing, and are persistent in reaching the goals of the project. These Contractors have an answer for all the five objections listed above. A true Design-Build Contractor must have the capability to design a project with ALL the Client/Owner’s project requirements fulfilled at the best value and in the shortest time frame. This feature, and the safety provided by the DB process, makes Design-Build the ideal choice for the right kind of projects.

Design-Build Construction is not “VE” Construction where parts of a design or system scope are sacrificed for the sake of cost saving. Value Engineering, or Cost Engineering, has its place but it is certainly NOT true Design-Build Construction.

Proponents of the Design–Build method of Project Delivery claim

1) Design–Build saves time and money for the owner.

2) Designers often make cost decisions that are outside their area of expertise.

3) A knowledgeable Contractor with extensive design experience, including experience with certain project types, is the best choice for a Designer.

4) Design–Build allows Owners to avoid being placed directly between the Architect/Engineer and the Contractor, hence dramatically reducing liability and costs. This is very important as claims are consistently less than in Plans and Spec’s construction.

Under Design–Bid–Build, the Owner takes on significant risks because of that position.

Design–Build is sometimes compared to the "master builder" approach, one of the oldest forms of construction procedure. Comparing Design–Build to Plans and Spec's, the authors of Design-Build Contracting Handbook noted that “From a historical perspective the so-called traditional 'plans and spec’s' approach is actually a very recent concept, only being in use approximately 150 years. In contrast, the design–build concept – also known as the 'master builder' concept—has been reported as being in use for over four millennia.”