Design-Build vs. Design Assist

Steve Murphy, PE, LEED, AP BD+C, and Director of electrical, mechanical, and plumbing services at Blach Construction explains his perspective on the difference between design-build, and design-assist.  Blach Construction, founded in 1970, is a Northern California general contractor with offices in Silicon Valley, Monterey, and Sacramento.  Their focus is building education, corporate offices, medical facilities, historic preservation, high technology, and non-profits. They are an AGC member and are recognized as a great place to work.  They were recognized by AGC-CA in 2010 and 2011 as having the best safety program in the state.  They have a hip and effective website.

Here is Steve: 

Design-Build and Design-Assist are not interchangeable. While these project delivery methods sound similar, they are in fact very different. The main difference I’ll address in this post is the designation of the firm that is legally responsible (and ultimately liable) for the design of the systems.

The project’s Engineers of Record (EORs) are design engineers that are responsible for interpreting the client’s needs and designing fully functional MEP systems for their building. Typically, there are different EORs for mechanical, electrical, plumbing and fire protection systems.

The drawings and specifications prepared by these EORs communicate the intent of the project to the building contractor. Ultimately, clients choose between what they want or what they can afford (I know it’s a shock, but these can be different at times!).  

In a pure “Design-Build” project, the different EORs are typically employed/contracted by the Design-Build MEP subcontractors. These subcontractors are solely responsible for designing, installing and commissioning the MEP systems to satisfy the intent of the project. The different Design-Build subcontractors collaborate as a team and are responsible for informing each other of how their system will impact the project overall.

In a “Design-Assist” project, the MEP EOR’s are typically hired by the project architect. These EOR’s are responsible for the project’s design and they coordinate closely with the other design team members (architect, structural engineer, landscape architect, civil engineer, etc.) to ensure that each individual system is designed to meet the intent of the project. 

Simply explained, MEP subcontractors are responsible (and liable) in a Design/Build project and the MEP consultant EOR’s and the architect are on the hook (from a liability standpoint) in a Design-Assist project.

This sounds right to me.  This division of ultimate responsibility, however, is often not stated crisply in design-assist contracts because owners and general contractors want to shove as much of the design responsibility down to a design-assist contractor as possible.  If the language is vague, goes the impulse, we can always argue that the design-assist contractor had ultimate responsibility, even if it's really design assist.  Better practice, IMHO, is to strive to make this division explicit and clear in the contract documents.