Considering the Means and Methods to Span Design and Construction

This article is included in the Great Things: Issue 6 edition of the DPR Newsletter.

The conventional means and methods “gap” between design and construction has grown wider as buildings have become more complex. DPR spoke to Greg Luth, principal at Bay Area-based structural engineering firm GPLA, on improving and optimizing the traditional linear process of design to drive greater collaboration and ownership of project outcomes.

exterior of hospital
GPLA provided rebar modeling for coordination and rebar shop drawings for the Sutter Health Eden Medical Center in Castro Valley, CA. Courtesy of Rien Van Rijthoven

Design isn’t a linear process, to be sure. From your perspective, is there anything that project teams can do to help optimize the workflow between design and construction?

Let’s take apart what typically happens during handoff from designer to contractor. The designer provides a detailed design, usually up to BIM Level of Development (LOD) 300, and then the contractor produces shop drawings, which means they figure out the rest of the details. And they’re thinking about how they're going to build it. That's when they start finding things like, maybe this detail isn't right or needs to be changed. And all of a sudden, the contractor is basically redesigning the building from the ground up to make it constructible.

In 2006, when I started 3D modeling, I said that I’d carry my designs all the way to LOD 400. That way, I know exactly what the means and methods are for construction. I decided that I was going to do all the shop drawings because the process won’t be as efficient unless I know how the project will be built.

But I still have to convince the contractor that I've done the shop drawings the best way possible. How do I do that? I talk to the superintendents and foremen. I ask, “What makes your life easy, what makes your life hard?” Everyone at GPLA is trained to ask those questions in the field, to spend time observing construction, to understand not just if they're building it according to the drawings but how they're building it.

How you design dictates how you build it. Not fully considering construction means and methods during the conceptual phase makes the whole process inefficient. And better design translates to higher the quality in the field and ultimately, a high-performing building.

Can you set the stage for us a bit? What is contributing to this gap between conventional design and construction in the field?

The design profession is spread out over a huge area from schematic to shop drawings, and there’s a gap in terms of level of detail produced during the design phase. Architects started hiring independent engineers like myself to keep them in the ballpark of constructability. In the past, the ballpark used to be small. If you were inside the ballpark, you’d be ok. Today, think about all the systems that go into building now and all the coordination that is needed; the ballpark is huge. Being in the ballpark isn't necessarily good enough.

What else has changed in the past 20 years is technology. We live in a digital era where we can produce an LOD 300 in a couple of days. But because our buildings have become more complex, coordination has gotten exponentially more complicated. And you can't do the coordination without the detail. Responsibility for that coordination has shifted onto the contractor. And they can't do it with just an LOD 300, typically, because they need more detail than what’s included there.

How do you see your role as an engineer on an integrated project team?

You help an architect by removing some of the constraints that might hinder their ability to be conceptually creative and push the limits of design in ways that are still constructable. I can look at a problem and suggest other ways that haven't been considered yet that I'm pretty sure would work from a structural point of view. I've freed the architect to explore alternatives. I do the same thing on the construction side. If I've got a particular part handled, the contractor can think outside the box as well. They’re better able to consider how a particular design decision influences the other things they would normally do.

Once you start looking at a problem from a different perspective, you never know what you're going to discover. Everybody that looks at it is going to bring their own expertise. And it always amazes me—the ideas that flow out once you've taken the guardrails off, and you realize the whole expanse of field we can play in.

What can we see from collaborative, early integration efforts that are different from the traditional bid-build process? Are we able to avoid problems before they arise?

It goes even further than avoiding stupid mistakes. It pushes us toward solutions that are unusual, that are exceptionally good, that are the result of having so many perspectives available on a single project.

I've been in the business for 40 years. What's the difference between a contractor and an engineer that's been in business for years? Contractors work on projects for years. Engineers work on 100 jobs a year, and they work with a different contractor on every job. There’s a phenomenal amount of knowledge available, and integrated teams have the benefit of leveraging those experiences upfront and throughout the project lifecycle. There's of course value in every role, but the ability to laterally problem solve is greatly enhanced by exposure to many different conditions and experience solving problems numerous ways.