Excerpted from WoodWorks’ Platte 15 Case Study.
When Crescent Real Estate, a developer known for making smart investments in better buildings, chose wood for their new office structure, people took notice. This five-story workspace–located in one of Denver’s most popular neighborhoods–incorporates a mass-timber frame, built using glued-laminated timber (glulam) beams and columns, as well as cross-laminated timber (CLT) floor and roof panels.Designers drew architectural inspiration from surrounding historic buildings while using wood to create a distinct, modern presence.
Platte Fifteen blends authenticity and sustainability with state-of-the-art construction technologies that link Denver’s pioneering past with its carbon-friendly future.
The majority of the five floors are dedicated to office space, with ground floor retail and two levels of concrete below. Soaring interior ceiling heights, outdoor patios and a rooftop deck provide unobstructed views and plenty of appeal for potential tenants.
We felt it was important to respect this historic site and reinterpret it in a contemporary way as part of this transformational opportunity for the city. Platte Fifteen gave us the opportunity to showcase the new generation of mass timber buildings in Denver.
The design team undertook a thorough analysis at the start of the project, studying both grid options and construction types. After reviewing various building materials, including an all-steel option,structural engineers opted for wood.1
The final design includes 3-ply CLT panels with glulam beams and exposed columns with minimalized connections. The roof — which is also 3-ply CLT — supports a terrace with large tree planters and Colorado snow loads. The CLT floor panels are topped with three inches of concrete, but the team used CLT as the diaphragm instead of concrete topping.
“We know tenants have different objectives, and wood is playing into our ability to attract them to our properties,” said said Conrad Suszynski, Co-CEO of Crescent Real Estate. “People are looking for openwork environments. And when they see Platte Fifteen, with its beautiful wood beams and exposed wood ceiling, and when they compare it to a standard concrete or steel building, it’s no contest.”
Denver, like many cities across the U.S., has a growing number of companies seeking a more sustainable ethos. With this emerging trend in mind, Crescent Real Estate wanted a project that featured natural materials, improved thermal performance, energy efficiency and better indoor air quality. Following a successful partnership with OZ Architecture and KL&A on The Loading Dock — a CLT structure in nearby Boulder — they applied their learning to a bigger building in a bigger market.2
“When tenants see the warmth of wood, it definitely resonates,” said Conrad Suszynski, Co-CEO of Crescent Real Estate. “It also resonates with us. We wanted to reduce the carbon footprint of Platte Fifteen, and mass timber helped us get there. We think it’s the industry’s job to be pushing these trends,and we are committed to finding a way to make it all work.”
Another common benefit of mass timber construction is speed of installation, and this rang true for Platte Fifteen. Crews began installing the wood system in November 2018, and the last panels were laid in March 2019, reducing construction time by 20 percent compared with a traditional steel structure.
“We appreciate the fact that wood is the only true sustainable building material; it literally regrows itself,” said Shawn Brannon, Project Manager with Adolfson & Peterson Construction. “We also appreciated that the wood portion of the project went together so well. Wood construction is so fast,and the tolerances are so accurate.”“It was exciting to bring mass timber and CLT to Denver, to be a pioneer like this,” said said Joseph Anastasi, Senior Associate at OZ Architecture. “We look forward to what’s next with wood, and to finding new ways to differentiate office buildings in this market.”