Even though the COVID-19 virus has tossed the U.S. economy a curveball, don’t expect it to throw the latest addition to Denver’s skyline, a 30-story, speculative office building, for a loop.
The so-called Block 162 is a joint venture of developers Patrinely Group LLC, Denver, and USAA Real Estate, San Antonio. When completed in late 2020, the tower will stand alone among the sources of new downtown Class-A office space for attracting legal, financial and technology-oriented tenants. In fact, Block 162 is one of a just a few speculative office high-rises to come to Denver’s central business district since the 1980s.
Much has changed since then. Both Colorado and the Denver area have grown extensively, the latter undergoing a population increase of 20% in the past decade, up to 720,000, according to the Census Bureau. The influx has translated into stronger market fundamentals and keener competition for tenants.
“Block 162 is seeing a lot of interest from firms looking to relocate to Denver from other parts of the U.S.,” says David Haltom, vice president with Patrinely.
Among the reasons is that tenant expectations also have evolved since the 1980s, with the $180-million Block 162 programmed to lead the pack in a robust market and perform well under more difficult post-pandemic conditions.
As the building nears completion, Patrinely and USAA are ramping up efforts to boost tenant interest in a less certain market than when construction began. Among other tactics, the developers have created a virtual tour, including drone videos and virtual tenant space walkthroughs, Haltom notes.
The development group is working with other project team members to employ 3D Matterport scanners, “allowing viewers to step into an actual core-and-shell floor space and see real views within the actual curtain wall line,” he says.
In part, the building’s design responds to the changing habits of office dwellers, who place a premium on flexible, sustainable workspace, in addition to amenities that reflect a more casual approach to work.
Those amenities include more lounges, collaborative and recreational venues or simply a space to take a break, says Raffael Scasserra, principal and design director with architect Gensler, Houston, a frequent collaborator with Patrinely Group.
Steel-framed office floors will provide internal column-free workspaces and generously proportioned, rectangular floorplates. That also allows for more flexible planning modules, in addition to the full-height glass windows with unobstructed views of Colorado’s Front Range, according to Haltom.
In all, some 19 office levels, averaging 29,500 sq ft, will rest on a larger post-tensioned concrete podium, whose 42,000-sq-ft floorplates will house a grade-level lobby and, above that, nine levels of parking.
Sandwiched between offices and parking, level 11 borrows a page or two from hospitality and residential playbooks, mixing social, fitness and meeting spaces that open onto an outdoor sky terrace via 40-ft-wide, accordion-like window walls. “We wanted to take advantage of the Denver climate by opening the building to the outdoors,” Scasserra says.
The mix of uses offered by the 29,500-sq-ft floorplate on the 11th floor will spill onto adjoining terrace space on the roof of the podium structure, says Haltom. “Our fitness club extends onto a landscaped outdoor lawn, where tenants can work out with free weights or engage in aerobics and other physical activity,” he says. Indoor social space will feature fireplaces and seating areas where tenants can work independently or collaborate. The corresponding outdoor space will include additional furnishings, plants and several fire pits.
In their aggregate, the spaces “reflect the blur between work and lifestyle as the two become more flexible,” says Scasserra. Lounge spaces, for instance, are “suitable for a quick cup of coffee and dashing off an email in the morning, for company or department meetings during the day or for an after-hours cocktail party in the evening,” he adds.
The building, under construction since 2018, is the culmination of a lengthy study begun in 2014 among the developers, Gensler and the Denver office of general contractor Swinerton, another longtime collaborator with Patrinely. It wasn’t until three years later, in 2017, that Patrinely and USAA signed a 99-year ground lease for the parcel. By that time, team members had fleshed out most of their plans.
“We assisted in working through design, constructibility and budget issues,” says Chad Holajter, project executive with Swinerton. Client and designer “knew exactly what they wanted,” he adds.
“We designed the building from the inside out,” says Haltom. Office floors dispense with interior columns by locating steel beams beneath concrete and steel deck floors in order to connect the 24 perimeter columns, spaced 30 ft on center, to the core, which is composed of shear walls, says David Chlebus, project director with Houston’s Cardno, the Block 162 structural engineer. Additionally, long-span girders extending between the perimeter and the core’s short end further alleviate the need for interior columns, he says.
Spacing among perimeter columns conforms with 5-ft planning modules, deemed ideal for either open-plan space or closed offices ranging from 10 ft to 15 ft wide, Scasserra says.
Lease spans from a typical core wall to the inside face of the enclosure measure about 44 ft—longer than the 40-ft to 42-ft spans typical of older office buildings. The larger spans are more efficient for contemporary office tenants and “pay dividends by adding population to a floor while providing greater flexibility in positioning workstations and corridors,” says Scasserra.
The deeper floorplates don’t compromise daylighting due to full-height exterior glass, which measures 10 ft from floor to dropped ceiling, according to Holajter. Additionally, continuous vertical metal fins placed between glazed members “bounce” light into interior spaces, says Scasserra. To avoid heat gain, insulated curtain wall units, measuring 1 in. thick, include a 0.5-in.-thick thermal break between inner and outer panes in addition to a low-e coating on the inside of the outboard panel.
With the building seeking LEED Gold certification, Gensler and Patrinely collaborated closely with ME Engineers, Denver, the MEP designer, to devise energy models that simulated the relationships between curtain wall options and the building’s mechanical system, says Lyle Hays, principal with ME. “The collaborative effort led to the optimization of a glazing system that met architectural objectives while satisfying energy goals,” he says.
To accommodate flexible floorplate configurations, from enclosed private offices to open-office plans, ME increased interior air ventilation by specifying a dedicated outside air system (DOAS) with a capacity 30% greater than required to meet minimum ASHRAE 62 requirements for typical office spaces.
Among the strategies it employed to promote sustainability, ME equipped the DOAS unit with an energy-recovery wheel to precondition air by transferring waste heat from the building’s exhaust and relief air systems, Hays says. Additionally, a high-efficiency chilled water plant is equipped with a water-side economizer, allowing the plant to produce chilled water for cooling processes while keeping the chillers offline. The water-side economizer is well suited for Denver’s dry climate, Hays says. Further, the building incorporates on-floor air-handling units that promote low static pressure system losses, allowing it to accrue significant energy savings.
At present, project team members expect the tower to top out in late June or early July. “We’re up to level 27 and pouring about a floor per week,” says Holajter. However, construction will extend beyond level 30, with crews stacking unitized glazed units to create a crown—or parapet. It rises 32.7 ft above the roofline. In addition to adding sculpture to the building, the parapet obscures the MEP penthouse and other rooftop elements, Scasserra says.
Despite the COVID-19 crisis, construction is proceeding according to schedule. “Swinerton and its subs haven’t missed a beat,” says Haltom.
“We drafted a site-specific plan that, among other initiatives, limits the number of workers who can ride a man hoist to five, each at 6-foot distance from each other,” Holajter says.
Swinerton also staggered times when crews arrive on site each morning. Upon arrival, all crew members have their temperatures taken and put on masks and gloves, Holajter says. Additionally, Swinerton has deployed a full-time crew to disinfect the site.