Inside the Mind of a Building Scientist – 4 Questions with Dr. Achilles Karagiozis
Forget the pristine white coat and controlled laboratory environment. For Achilles Karagiozis, Global Director of Building Science at Owens Corning, science takes place on the job site, often working hands-on alongside the builders, architects, contractors and crews involved in achieving more comfortable, energy efficient, high performance homes.
We caught up with Achilles and talked about how Building Science is changing the way homebuilders build today.
You’re correct, but at Owens Corning we’re committed to keeping the discipline of building science pure. Using building science, we are able to view the house as a system, where the parts come together to deliver a comfortable, high performance environment. Of course, experiments will always be part of science to prove or disprove theories, but those experiments should not be conducted in the commercial market, where unintended consequences can be difficult to correct, and builder brands can be damaged. Owens Corning deploys a three prong approach. First, experiments and analyses are performed at the material level. Subsystem and system laboratory testing is then performed, followed by monitoring of the whole building. In one study, Owens Corning conducted 1,070 “experiments” in a controlled environment to assess how air flows through the walls of a home and we learned that achieving a tight home requires much, much more than focusing on the wall. When we start thinking “big picture” about the home as a system, we can look to science to inform prescriptions. And meeting and exceeding performance that requires us to “prove” the science – like the requirement to conduct a blower door test, allow us to back up the value that building science brings to the housing equation.
How did Owens Corning work alongside Element Design Build to meet the challenges imposed by The New American Home®?
It all starts with the builder – whether it’s The New American Home or a home for a family in any community. The first step in achieving a high performance home is to understand the builder’s objective – what he’s trying to accomplish on behalf of his buyer? Then you take a look back at a system of considerations – codes, the climate, topography and the design aesthetic. Josh Moser and the team at Element Design Build said up front, “The home is basically a glass house in a desert. “It would’ve been easy to say, “take out some windows, but where is the challenge in that?”
Instead, we turned to science and technology, using tools like Wärme und Feuchte Instationär (WUFI®) modeling system (editor’s note, Dr. Karagiozis helped create predictive modeling) to assess all of the unique variables – climate, orientation, topography, etc. It’s true – you can’t move the mountain, but using technology, we were able to adapt The New American Home® to address its location adjacent to a mountainside. The team also simulated the hours of daylight the home receives, occupants’ level of clothing and more. Then we used this information to prescribe systems to define building material recommendations, such as installing FOAMULAR® 250 under the slab, perimeter insulation and RimSealR airsealing, to achieve energy goals.
How does the phrase, “Location, Location, Location” impact building science?
A builder won’t build the same home in Las Vegas that he builds in Alberta, Canada or California. Codes are one factor that building scientists consider, but they’re usually just the starting point. As I noted earlier, most builders have specific performance goals they want to achieve, which are often well above basic code requirements, so it’s important to look at how the home is going to perform across seasons in various climates. Analysis of climatic variables is key to prescribing the right products. Many people think of Las Vegas as a hot climate – and it is during many months of the year. But it can also get very cold at night. So when we were working with Element Design Build we considered where continuous insulation, blown-in insulation and air sealing could provide a tight environment that manages that temperature delta to ensure home durability and keep occupants comfortable in every season.
And this approach isn’t just for show homes. When Canada launched its ecoEnergy Innovation Initiative, our Canadian team had a chance to help builders demonstrate the feasibility of building Net-Zero Energy Housing in some very cold regions.
California is a good example of a region that presents both climate-driven and code-driven challenges. We worked with Shea Homes, leveraging Owens Corning ProPink® Insulation from foundation to roofline. In addition to blown-in wall systems, we implemented the ProPink® High Performance Conditioned Attic system to ensure thermal, air and moisture control in the attic space. This application created a buffer zone between exterior temperatures and the livable space of the home.
Builders in every region take pride in building homes of enduring value, and making homeowners comfortable. In Texas, Ron Davis Custom Homes worked with Owens Corning to deliver performance against 2020 performance mandates. Again, it all comes down to working with the builder, considering the climate and using building science to prescribe the right building practices.
In just one sentence, how does Building Science lead to better building?
Building Science helps builders achieve high-performance homes in a cost-effective manner by prescribing the appropriate materials used throughout the home system.