Case Studies
Star Lofts: Mass Timber/Light-Frame Hybrid Optimizes Affordable Housing Design
Value engineering decisions key for Des Moines developers
Cutler Development kept Star Lofts both sustainable and financially viable by combining mass timber with light-frame wood construction. The hybrid design highlights the carbon advantages of building with wood as well as the benefits of blending different construction methodologies and using materials where they make the most sense.
It’s not unusual for initial designs to come back as too expensive, and that’s what happened with Star Lofts.
“It took a couple iterations to land on a design that was cost effective. Our shift to a hybrid design was pivotal in terms of making this budget work. Mass timber brought efficiencies in terms of schedule and sequencing; we also benefitted in that we didn’t have to cover it with drywall. The light-frame lumber added value in other ways and was easy for crews to frame and insulate.”
– Scott Cutler, Cutler Development
Project Details
Location: Des Moines, IA
Size: 22,770 square feet
Construction Type: V-B
Completed: Fall 2024
Project Team
Developer/Owner: Cutler Development and Anawim Housing
Architect: ID8 Architects
Structural Engineer: KPFF
General Contractor: Cutler Construction
Mass Timber Installer: Hildreth Construction Services
CLT Manufacturer: Sterling Structural
Glulam Manufacturer: Timberlab (previously American Laminators)
Acoustic Assemblies: Rothoblaas
A Quiet First for Floor Design
Cutler Development wanted to provide the best possible living experience for tenants, which means they needed to manage acoustics. Star Lofts features a first-of-its-kind flooring assembly that achieves a 55 STC/50 IIC rating while leaving the top layer as exposed concrete.
“It’s a design innovation that we’re really proud of,” said Scott. “But full credit goes to our general contractor, Cutler Construction, run by my brother Peter, for coming up with the concept. The 3-ply CLT allowed us to make the project pencil financially, but when we moved from a 5-ply to a 3-ply panel, we lost the mass we needed for acoustics. We wanted to leave those concrete decks exposed to provide the finished floor surface. So, by adding the gypcrete and a sound mat, which is made using recycle materials, it gave us the true mass-spring-mass assembly we needed. The assembly meets code requirements, and the manufacturer tested it to make sure it met our acoustic goals.”
Cutler Construction crews also installed a self-adhesive strip for perimeter separation to attenuate impact sound under the lumber-framed walls.
Get the latest case studies, technical resources and WoodWorks updates in your inbox. Sign up here.
