Olsson Associates


Design-build project delivery

Wednesday, October 18, 2017

Clif Warren, Senior Engineer


Design-build contracts are often used to accomplish architecture, engineering, and construction of facilities, infrastructure, and public works projects. This type of contract provides for integrated design and construction services to be provided by one entity, the design-builder, under a single contract.

In the design-build (D-B) scenario, the owner issues a request for proposal (RFP) that communicates the requirements, needs, instructions, and design-builder selection criteria. Proposers, or respondents, to the RFP are most often integrated teams of designers and general contractors. However, in many cases the proposer/respondent is a single firm that has both design and construction capabilities in-house. Most often when the design-builder is a team made up of separate design and construction firms, the construction firm proposes as the prime contractor. After the identified competition activities are completed, the owner then selects the winning D-B team contractor. The contractor is responsible and accountable for performing the completely integrated design and construction services. The owner manages and monitors the contractor, ensuring the owner’s requirements are met.

As an engineering firm, we may find ourselves filling various roles in the D-B process. We may serve as a designer teamed with a D-B builder (general contractor) to provide the integrated design and construction services for the owner. This is sometimes referred to as architect-engineer (AE) 2 services. In another situation, we may serve as the owner’s consultant or representative during the project planning, preparation of an RFP, selection of a D-B contractor, and/or oversight of the project during final design and actual construction. This is sometimes referred to as AE 1 services.


Prior to joining Olsson, I spent many years with an agency that frequently used D-B contracts. Many varied and complex projects were executed successfully under this scenario. Advantages of this delivery process included the following:

  • Placing accountability for both design and construction on a single entity, therefore reducing some risks on the agency
  • Gaining innovation from an integrated team tasked with meeting performance requirements
  • Allowing construction funds to be awarded sooner, which was sometimes necessary because of the late receipt of project funds

There were times this method caused unique challenges to some projects’ timely completion, and at my former agency, we made efforts to improve the problem. We analyzed recently completed projects and identified common issues, some of which occurred during the RFP preparation, contractor selection process, and/or the design process and would likely be of interest to designers, owners, and consultants. These common issues included the following:

1) Projects were completed behind schedule: 60 percent experienced delays because of significant conflicting requirements or discrepancies within the contract documents. The conflicts and discrepancies were either within the RFP, between the RFP and the contractor’s accepted proposal, or both. When these issues surfaced after the contract was awarded, time and cost growth were encountered for activities such as answering requests for information, processing change orders, and performing rework.

Once a D-B contract is awarded, the RFP and the contractor’s accepted proposal become a part of the contract, making it more difficult to resolve conflicting language within and between these documents. While contract documents are never perfect, this illustrates the importance of producing clear, quality documents with minimal errors, discrepancies, and conflicting information, and the importance of reviewing and working to resolve as many of these types of issues prior to award as is practical.

2) Projects fell behind schedule during the design preparation periods: These were the periods where design documents were prepared, reviewed, approved, and issued for construction. Almost 90 percent of the late projects experienced a total design duration that exceeded 25 percent of the total project duration. Our experience was that most of the initial design work was performed on time, while most of the time growth occurred in the design review, comment resolution, design approval, and final document periods. Half of the projects experienced a significant lag between when the design was approved and when construction actually started. 

There could be many reasons for the significant delays during the design acceptance and approval periods. It is likely some reasons were because of the same discrepancy and conflicting information issues discussed in the previous section. However, due to its prevalence among the late projects, it is reasonable to assume there could be a lack of schedule discipline as well. Much of the design work and reviews were performed off-site or at a home office by designers, owners, owner consultants, and users. There may also have been a bit of “out of sight, out of mind” thinking as far as schedule monitoring was concerned. The Design Build Institute of America (DBIA) recommends co-locating the design and construction members of D-B teams as one of their recommended best practices. When feasible, this would likely be one benefit for schedule management. A simple thing all team members can do is to remain aware of the schedule and the respective activity durations and planned timeframes, and perform tasks accordingly.

3) Issues identified during design reviews were not resolved before construction: This was reported in a small number of the late projects and it resulted in delays as the issues resurfaced either during construction, at inspection intervals, or after the turnover of the facility. In each case, the technical issue was unique. The fact that it was left unresolved during the design issue resolution and acceptance period is what led to more exaggerated delays further in the project. This just highlights the risks involved with moving forward with unresolved design issues. It is usually in everyone’s best interest to attempt to resolve the issue as early as practical.


The D-B contracting method is an effective project delivery method. Since D-B is truly an integrated approach to delivering projects, the tasks by all team members have an impact on timely performance. Some common issues discussed above can be overcome by adopting the following practices:

  • Being vigilant in RFP and proposal preparations to include exercising proper quality control.
  • Design concepts with general contractor’s concurrence should be reviewed and approved by the owner and users early in the process. Early identification of issues and resolution at the lowest level creates the best situation for a successful outcome.
  • Performing proper reviews of proposals during the D-B builder selection process. 
  • Establishing a reasonable project schedule with realistic durations for all activities. 
  • Awareness of the accepted project schedule by all team members, including the prime and subcontractors, owners, and their consultants, and performance of their respective duties within the established timeframes.   

 If you have any questions, call me at 918.645.9663 or email cwarren@olssonassociates.com.



Clif Warren, PE

Senior Engineer

Clif has over 33 years of engineering, management and leadership experience. In his former position at United States Army Corps of Enigneers, he led approximately 170 employees within four armed      forces branches and three construction area offices (with subordinate resident and project offices) in the engineering, design and construction management of military construction and civil works projects.



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