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The Professional Services Perspective: Design-Assist Procurement and Collaboration

Design-assist procurement is the best possible approach to developing and completing design, engineering and construction of custom curtain wall and cladding projects. All curtain wall projects should be executed with some form of design-assist or design-engineering. Design-assist, or DA, is a collaborative process with a defined schedule and set of deliverables, whereby the architect, contractor, curtain wall consultant, owner (as applicable), exterior wall subcontractor, and their design and engineering agent, participate in a collaborative, iterative, real-time exercise to define, design, collaborate, review and deliver a coordinated curtain wall system that meets the project performance specification and aesthetic goals.

There are different forms this process can take, but I believe it is best expressed when the contractual procurement method includes the DA process first, with a guaranteed max pricing around a specific scope or design context.

Here are a few benefits of this method:

  1. Facilitates early collaboration of the major stakeholders. This creates more alignment and typically improves the delegated design and review process. Collaboration creates a better working product, reduces risk and builds good will amongst the project team.

  2. Allows for a more fully informed approval process and systematic review of the system design, proposal drawings, profile drawings (dies and details), and engineering calculations on how closely the building aesthetic and performance can be matched by the system.

  3. Transparently vets system performance, incorporating review of sightlines, transitions between systems, engineering, thermal analysis, adjacencies, STC, and other coordinated issues visibly and directly.  

  4. Assesses and assimilates architecture, construction, fabrication, procurement, logistics, installation, and other holistic project needs and concerns as part of the design process and boundary conditions, enabling better downstream project management.

  5. Allows concurrent pricing exercises by the exterior wall subcontractor, which can inform the owner, GC, suppliers, consultant and other stakeholders. This allows the entire team to work in an informed manner with clearer cause-and-effect understanding.

  6. Brings a “shared reality” to the process and project. A shared reality brings everyone into the “same boat,” typically reduces project risk, and breaks down barriers of communication. This can aid in a positive experience, and a better work product.

  7. Facilitates a quicker turnaround of shop drawing and engineering submittals, since everyone knows what to expect in the context of the system design.

Words of caution:

  1. DA is NOT an open-ended design process where the shop drawing reviews are used throughout the project as a means for the architect to figure out what they really want on their building. If this is the project procurement method and definition of design-assist, then the exterior wall subcontractor will have to draw some boundary lines and provide pricing and scope to match.

  2. DA is NOT a “value-engineering” process to look at any form of a cladding type or aesthetic. It’s only a value-engineering process within the context of finding cost savings for the specified system design and orientation. Any new permutations or design changes should be defined as a change order. Base design alternatives are bid alternates and should take place outside the DA process.

 I’ve been involved personally and as a corporation in so many successful design-assist projects, that I’d love for all projects to be done in this form. There have been a few failed experiences along the way, but far less than other traditionally executed projects where everyone works in silos and uses email as a primary collaboration tool (it’s not a collaboration tool.)

I’d like to suggest that those of us who make our living doing this meaningful work make design-assist procurement a rally cry for improving the process and experience we all share on our typically complex and critical path driven projects. I believe we can create better experiences for ourselves and our clients, and make the world a better place.

I’d like to hear more from the readers. Please comment and let’s keep the conversation going.

John Wheaton is the founder & co-owner of Wheaton & Sprague Engineering, Inc., also known as Wheaton Sprague Building Envelope. The firm provides full service design, engineering and consulting services for the curtain wall/building envelope/building enclosure industry, and works at “Creating Structure” for clients. He can be reached at and on Twitter, @JohnLWheaton1.

The opinions expressed here are those of the individual author and do not necessarily reflect those of the National Glass Association, Glass Magazine editors, or other glassblog contributors.


John Wheaton headshot

John Wheaton

John Wheaton is the founder and co-owner of Wheaton Sprague Building Envelope, He can be reached at and on Twitter, @JohnLWheaton1.