When I give presentations to engineers, I like to ask the question, “How many of you have ever designed something that cannot physically be built? Raise your hand if you have.”
I will put my hand up and look around the room. Typically, no one—or maybe one or two engineers—will timidly raise their hand. I keep my hand up and say, “The correct answer is all of you that have been designing buildings for more than a few years have sent out a design that cannot be built, and you likely don’t know about it because you have not visited your job sites or talked to the contractors building your projects.”
I continue: “If you notice, I have my hand up because I have issued dozens of designs that cannot physically be built. But the difference is that my contractor clients have been very good about telling me about my mistakes and helping me work with them on a solution that is buildable and meets the design criteria.”
As design professionals, engineers and architects must provide designs that meet the building code, fire code and other state and local construction and safety requirements. What they often forget is that just because something can be drawn and passes the clash detection in their building information modeling does not mean it can be built, and even more important, that it can be built safely.
We as design professionals are sworn to protect the health and safety of the public. We need to realize that this does not just include the people who use the buildings we design, but the people who build them as well. As contractors, we will often argue with our general contractors about other trades get in our way, but it is not that often that contractors get to tell engineers that if they had moved the HVAC duct over three feet, or if they had lowered the soffit by three inches, the system would have been much easier and safer to build.
At a recent peer safety review, I witnessed this firsthand: There was a four-story medical facility that in our post-COVID-19 world had some very sophisticated air handling and filtering equipment, along with the enhanced structural systems and backup electrical systems required for surgical facilities. With all of these mechanical and electrical systems, it was nearly impossible for all the trades, including the drywall contractors, to properly install the ductwork, piping, wires, walls and ceilings as shown on the contract documents. And of course, many of these systems, including the fireproofing and firestopping, would have to be inspected before construction was completed.
There is not a simple answer for getting designers to consider constructability, but a partial solution is to keep the lines of communication open between the building and system designers and the contractors building these systems.
Having delegated design engineers for section 05 40 00 steel framing helps because these engineers work for the contractors and get immediate feedback when their designs don’t fit or they clash with other systems.
Having contractors hired early and engaged in design-build work is also helpful, especially on load-bearing projects, where there is less flexibility in running piping and wiring through bearing walls and shear walls. Having estimators with field experience also helps. They can more easily recognize access and clearance problems early and include notes and exceptions with their bids, flagging areas of concern.
There will always be parts of buildings that are difficult to build and finish: ceilings inside 20-story hotel atriums, perimeters of open stair towers, small plenum enclosures and fire-rated vertical chases. Prefabrication can provide some solutions, but not all.
At his presentation during the 2023 AWCI Industry Leaders Conference, safety evangelist TJ Lyons showed complex ceiling and duct systems built at ground level, with wiring and piping roughed in, before being lifted into place. This not only solved access issues, but it made construction safer by having less workers at height and less need for ladders and lifts.
Tool manufacturers are providing some solutions, such as pin guns made for high overhead reach so that installers can stand at floor level when attaching to the underside of a slab, and right-angle and narrow tools that allow framers to make attachments between studs and behind ductwork.
Despite all this, many of our projects are still difficult to build, and trades continue to get in each other’s way. Part of the answer will be for associations such as AWCI to provide education resources for architects and engineers, increasing awareness of problems and design solutions.
Trends in architecture are for greener, less carbon-intensive solutions for everything, including buildings. But if work has to be ripped out and redone because of access and clash issues, it increases both environmental impact and costs. With today’s complex buildings, design professionals have a full plate just keeping up with the latest codes, material choices and building technology. Contractors can help make their job easier by communicating the issues of access and constructability.
