Project Challenge
The Samueli School of Engineering at University of California, Irvine, known for its academic success, entered the 2023 Orange County Sustainability Decathlon competition to empower its students to design and build an innovative and sustainable house. The challenge was to build a structure that would be 100% reliant on renewable energy, a goal that California is trying to meet for all new construction by 2045. To do this, UC Irvine partnered with building materials manufacturers, like Atlas Roofing Corporation, who donated its ACFoam Nail Base roof insulation. UC Irvine students collaborated with a local junior college, joining forces to present their market-ready homes in a sustainable, educational village open to the public at the Orange County Fairgrounds.
UC Irvine entered the competition because the program aligned with the university’s mission to educate not only the students, but also the community at large. “The competition fit nicely with the expertise required, including the focus on energy efficiency and sustainability, while providing students an opportunity for a real-world experiential learning opportunity,” stated Mark Walter, professor of teaching in mechanical and aerospace engineering at UC Irvine. “It took the students out of the more theoretical classwork to show them elements that were more open-ended, with problem solving challenges outside of the classroom.” The focus of the team was to construct the most sustainable, resilient, and affordable house they could imagine. Walter, along with Jennifer Wilkens, director of special programs, led the students and faculty volunteers in this hands-on project.
There were approximately two hundred students involved in the collaboration between the two schools working on all aspects of the 750 square foot home, from design and architecture to electrical, plumbing and construction. To accomplish the most sustainable and resilient house possible, the team considered many iterations to combine the best engineering, materials, technology, architecture, and interior design standards into every aspect of the project. The complex project concluded with a public demonstration and competition that highlighted the features, functions, and materials in the house.
Approach
The team began by designing the style of the home and identifying eco-friendly products, like Atlas ACFoam Nail Base insulation that would meet specific environmental and sustainability best practices. There were also unique considerations for the home, including that it is an Accessory Dwelling Unit (ADU), a regulatory term for a secondary house or apartment that shares the building lot of a primary home, which is common in the state of California. With that in mind, it needed to fit in a backyard. Additionally, the house being donated to the Homeless Intervention Services of Orange County, which will assist people transitioning out of homelessness or poor foster care conditions. Finally, the structure needed to be modular to allow for transportation to the competition, and then to the final location.
From a design perspective, the team was challenged with accommodating the modular construction to allow it to come apart for transportation. The pieces could be no larger than eight feet to allow for transportation on the highway. The ADU is 750 square feet and consists of a base module (32’x16’), and
a bonus module (16’x16’). Both these modules come apart into two pieces, with four modules total. The roof system was designed using a cold-formed steel system. The distinctive, butterfly style roof stood out and drew people to the beautiful and modern design.
The products selected for the house had to meet environmental codes and sustainability practices. The team was looking for a roof insulation product with specific characteristics and that’s when the team started working with Atlas. “Working with Atlas was fabulous,” said Walter. “They were on board to donate the product, which was significant for us. Since this is not a house that’s being sold, everything had to be done through in-kind product donations. We were grateful for Atlas for being so easy to work with.”
The roof product installed was ACFoam Nail Base, a thermally efficient closed cell polyiso insulation board combined with a nailable substrate. The product provided a high R-value and helped the team address the modularity for the project. It’s important to install a high-performing insulated roof system since significant heat loss can occur through the roof. To achieve long-term energy conservation and occupant comfort, the team designed the roof assembly to provide a total R-value of 54 using continuous insulation in addition to other insulation components, exceeding the goals originally set. The roof trusses were filled with fiberglass bat insulation and an added layer of spray foam for air sealing purposes. The 2” ACFoam Nail Base was installed atop the OSB roof deck, which effectively provided an R-13 and reduced thermal bridging. This was an important part of the system to make sure the hot roof or an unventilated roof is completely air sealed. The modular aspect of the house also led the team to select ACFoam Nail Base because it would accommodate with the need to disassemble the house and put it back together. Since the polyiso insulation boards were easy to cut and install with the incorporated OSB, it made the process much faster.
Impact
The team had an aggressive build cycle completing construction in under a month and a half during the final leg of the 18-month project for the Orange County Sustainability Decathlon. The easy-to-install products selected, including ACFoam Nail Base, were critical to help the team achieve their goal.
“The Atlas roof insulation performed extremely well,” said Walter. “During the entire competition period, we really didn’t see a need to run the air conditioning system. It was warm during the days with cool nights, but the house stayed very stable and a consistent temperature. We believe this is largely due to the roof insulation since that’s where a lot of the heat would either be coming in during the day or leaving at night.”
The ADU home was judged on ten distinct categories. The panel of judges, subject experts in their respective fields, were impressed by how well the house was insulated as well as how knowledgeable the students were when speaking about the design and products included in the home. The judges not only loved the home, but the cherry on top was the team winning first place overall in engineering, construction, and energy efficiency which was directly attributed to the well-insulated roof, wall, and
Mechanical Electrical Plumbing (MEP) systems. The team also received second place in sustainability and resilience.
“What we really loved seeing is that it provided an experience the students can draw upon when looking for a full-time job,” said Wilkens. “It was very important for the students to have this experiential learning, especially because industry partners are often saying they’re not ready for the job market because they don’t have the practical skills needed. So, a project like this combines all the different skill sets they will need in the job market and also gives them really important life lessons,” continued Wilkens.
Both Wilkens and Walter agree that some of the best memories from the project were seeing the students come together, work hard and proudly accepting the awards on stage.
