Hook
“Approved equal” doesn’t necessarily mean equivalent.It’s one of the more common moments on a façade project.The specified system is a known quantity. Then a substitution request arrives, often with a lower price and a product data sheet that looks very similar.On paper, the numbers can look close.But when I review a substitution, I’m usually looking well past the headline values:Test reports - were they performed at a comparable size, configuration, and design pressure, or only on a standard test specimen?Thermal performance - is the U-factor for the whole assembly at the project’s actual unit sizes, or for a reference size?Structural capacity - do the mullion profiles, anchors, and reinforcement still work at the project’s spans and loads?Interfaces - does the system still tie into the air and water barrier, the slab edge, and the perimeter fire containment the way the design assumed?Lead time and support - can the manufacturer actually deliver, and who is on site when questions come up?None of this means a substitution is a bad idea. Sometimes it’s the right call for the project.But the decision should be made on verified performance, not on a similar looking data sheet.What do you check first when a substitution request lands on your desk?
