Building Homes That Deliver Form and Function Starts With This

Form without function is a quick recipe for problems on the jobsite and after 

By Graham Davis | July 13, 2020
Frank Lloyd Wright's Fallingwater in Mill Run, Pa., has been plagued by structural issues and water leaks
Form is front and center in Frank Lloyd Wright's masterpiece Fallingwater, while flawed functionality has resulted in a host of structural flaws and water intrusion problems for the iconic building. | Photo: Surfsupusa / Wikimedia Commons

I was reminded of the age-old challenge of how to build something beautiful to behold but still functional in the real and often messy world, when I recently toured Fallingwater, in Mill Run, Pa., one of the most recognizable residential masterpieces by one of the best-known architects in modern history, Frank Lloyd Wright. 

As I walked through this beautiful piece of architectural history with two other colleagues—all of us building science professionals—it quickly became apparent that we needed to remove our building science glasses and stuff them in our pocket protectors for the tour. 


While Mr. Wright did a marvelous job of incorporating his architecture into the natural setting of a creek that runs alongside and underneath this masterpiece, the rainwater and occasional snow runoff on this flat-roofed house wasn’t well managed from the start ... and has lead to years of troublesome maintenance



A Common (and Problematic) Scenario 

I remember once entering a model home by the builder I worked for at the time. The house was at the rough framing stage and I was accompanied by the HVAC installer and the HVAC company’s owner who were there to begin the installation of that system. 

Remarkably, it was the first time either of them had ever seen the house … under construction or on paper! Neither they nor any other HVAC professional was involved in the builder’s design process—a recipe for potential problems with system installation and, once the house is finished, sold, and occupied, with system operation.


pinched dsucts in home HVAC are a common problem when HVAC subcontractors aren't involved in planning
Duct placement is often an afterthought, but when ducts are pinched and restricted due to lack of space, it’s impossible for them to perform as they should. | Photo: courtesy IBACOS


In fact, in my experience then and since, it’s far too common for HVAC, structural, and building-performance experts not to be invited into the design process until that process is more than 50% complete. As a result, a builder may end up with a design featuring dysfunctional rooflines, inadequate mechanical chase capacity, and architectural details that are a nightmare to properly protect from water intrusion.


Include the Experts From the Start 

I’ve sat in on a few design charrettes, and they’re a lot of fun. The participants are filled with imaginative ideas spilling out like a spring rain overflowing an undersize gutter.

But creativity must be balanced by someone in the room with an eye on performance and durability from the start. Too much to ask? Not if you have the intention of promoting yourself as a quality-minded, high-performance home builder.

In planning your next design charrette, invite your structural and mechanical engineers and someone well-versed in water management (the kind that falls out of the sky rather than flows through the creek) so they can lend their expertise. 


this roof plane/wall intersection detail will result in water intrusion and leaks
A common design flaw is a roof plane driving down to a very restricted valley termination against a wall, which causes problems, especially in cold or wet climates. | Photo: courtesy IBACOS


this incorrect window flashing and roof edge termination detail that will result in leaks
Window flashing that is too close to roof-edge terminations presents significant challenges, and should be identified in the design phase, not in the field. | Photo: courtesy IBACOS



installing a window in the shower is not a good idea
Windows situated below the showerhead are inherently problematic for leaking into the framing cavity and causing latent defects. Better to place the window higher and away from a direct hit from shower water. | Photo: courtesy IBACOS


A good building performance expert can help keep an eye on the continuity of the drainage plane, thermal boundaries, and potential conflicts with roof designs, among many other details that are often overlooked when the emphasis is too focused on aesthetics alone. 

Let’s face it, there’s never a more affordable time to fix a problem than when it first shows up on paper. After that, the costs grow exponentially.


Graham Davis drives quality and performance in home building as a building performance specialist of the PERFORM Builder Solutions team at IBACOS.