Skip to main content
Edit PageStyle GuideControl Panel

Cornerstone Completes First Elementary School in Region to Feature Mass Timber

Cornerstone General Contractors, Inc. recently completed the construction of the region’s first elementary school to utilize mass timber building elements - Hilltop Heritage Elementary School in Renton. The new school opened for excited students and staff on the first day of school, August 30, but celebrated the facility’s grand opening on Thursday, October 12, 2023.

In front of students, families, teachers, staff, community members and project partners, representatives of the Hilltop Heritage “Hummingbirds” cut a ceremonial ribbon to commemorate the official opening of their new 85,000-square-foot facility. The school was built to accommodate the growth and increasing enrollment within the Renton School District and can serve up to 650 students.

Designed by Hutteball + Oremus Architecture, and engineered by Coughlin Porter Lundeen, the 30-classroom structure uses mass timber elements as the primary structural framing system.

Mass timber is also known as cross-laminated timber or CLT – an engineered wood product made from layers of solid-sawn lumber that has been glued together. CLT is a sustainable building product that is lightweight, yet strong and features increased fire safety performance, thermal insulation and carbon capture when compared to steel. To date, few K-12 schools have been constructed with mass timber as the primary structural framing system.

“Hilltop Heritage Elementary is truly a special school with its unprecedented use of mass timber in the Puget Sound area,” said Chris Duvall, principal for Coughlin Porter Lundeen, the engineering firm for the project. “What a fun challenge, structurally and beyond, and a rewarding experience. We all learned so much; so apropos for a school project.”

The interest in mass timber construction has blossomed in recent years due to owners seeking to build more sustainably with a reduced carbon footprint and using more locally sourced materials. Owners may also be drawn to mass timber for efficiencies in cost and schedule.

The practice of designing spaces that include natural elements such as wood and stone to connect building occupants more closely with nature is called biophilia. Proponents of biophilic design claim it supports health, well-being and cognitive function whether utilized in office spaces, public spaces or educational facilities.

“With the utilization of mass timber, we’ve helped to create a warm and inviting space for the students and staff,” said Gerard Boulanger, Cornerstone’s project manager. “What a great place to work, study and learn more about the world. Maybe we’ll inspire the next generation of builders right here at Hilltop Heritage.”