The city of Denver has set goals for buildings to become more energy-efficient and less polluting. Built in the late 19th century, the landmark Equitable Building is undergoing a behind-the-scenes transformation to meet those goals in the 21st century.
The building, on the National Register of Historic Places, is switching from the downtown steam-heat loop, which has warmed the nine-story structure since its opening in 1892, to a new natural gas system. Most of the work being done to make the 133-year-old building more energy-efficient is taking place inside, behind the exterior that features Colorado granite blocks and bricks, terra cotta ornamentation and a Palladian-style window, which has three separate sections.
But a big part of the update, a 22,000-pound boiler plant, is on the roof. There wasn’t enough room inside to install the plant and comply with city codes. The property manager, Elevate Real Estate Services Inc., worked with Braconier, a Colorado-based mechanical engineering firm, to come up with the solution.
Traffic was blocked off around the building at 730 17th St. on Sept. 27 as a crane lifted a rectangular box to the roof. The boiler plant is about 23 feet long, 12 feet wide and 12 feet high. The crews lowered it onto a platform that used to hold heating and air conditioning equipment.
“From the historical compliance standpoint, we went through a whole approval process with Historic Denver, making sure this wasn’t going to be overly visible from the street level,” said Andrew Glaser, vice president of operations with Elevate.
Historic Denver, a nonprofit advocacy organization, has an easement on the Equitable Building’s facade.
The Equitable Life Assurance Company built what became an anchor of Denver’s growing financial district on 17th Street, dubbed the “Wall Street of the West.” The building’s architecture is Italian Renaissance Revival. The floor plan is in the shape of two back-to-back E’s.
The opulent interior has hundreds of thousands of mosaic tiles on the vaulted ceilings on the first floor; marble pillars, walls and floors; chandeliers; a bronze staircase; and a Tiffany stained glass window.
Elevate is overseeing $5.5 million in work on the building, including about $2.5 million to convert to gas heat. Other upgrades are modernizing the elevators, improving the fire alarm system and restoring parts of the facade.
The new heating system will not only help the Equitable Building to comply with city energy-efficiency policies, it should dramatically slash the building’s energy bill. The building, whose offices are owned by individual users, is paying about $200,000 a year for heat, or more than half of the annual utility costs.
Glaser said the energy costs are expected to drop by about 40% with the new system.
The steam loop, which heats most large buildings in Denver’s downtown core, is more than 100 years old and inefficient, said Emily Gedeon, spokeswoman for the city’s Office of Climate Action, Sustainability and Resiliency. She said rates have doubled in the past decade.
The city completed a feasibility study on a shared, carbon-free heating and cooling system for downtown and received a $4.9 million grant for a pilot project.
Glaser said Elevate, which manages the property as the commercial equivalent of a homeowners association, explored different alternatives for heating the building: heat pumps, electricity and natural gas. Heat pumps, which can cool and heat, would have required modifications in every unit in the building. The current cooling system is only halfway through its life span, Glaser said.
And converting to electricity would have cost double the amount of gas to operate, according to Elevate.
Balancing history with new standards
With the conversion to natural gas, Elevate can use the existing distribution system to deliver heat throughout the building. New pipes and pumps are being constructed in a room just below the roof. Equipment in the basement that draws in the steam and pumps it to the distribution network will be demolished once everything is up and running.
When it became clear that a gas boiler plant wouldn’t fit in the basement, Braconier helped Elevate engineer “this one-of-a-kind solution,” Glaser said.
Braconier, founded in 1906, previously worked on changing the nearby Johns Manville Plaza from steam heat. The company had the Equitable Building boiler plant prefabricated offsite and used LiDAR — light detection and ranging technology — to create 3-D images to craft a computer model of the building. Following the models, the company could put together much of the pipelines offsite, knowing the structures would fit the space.
“Everything comes in, and it’s just snapped together like a Lego set,” said Sean Jackman, special projects manager for Braconier.
Glaser said the 175,000-square-foot building has surpassed the city’s energy efficiency target — energy used per square foot — for 2028. Equitable’s rating is 57.1, and the 2032 target is 48.3.
“We’re very confident that between the gas conversion and the other ancillary things, we’re be able to achieve that,” Glaser said.
The building’s rating on the federal-backed Energy Star program that measures energy performance is 83 on a scale where 100 is the best, Glaser said. The granite foundation and perimeter wall provide “great insulating value,” he said.
“The Equitable Building has weathered a lot of storms the last 133 years: the silver downturn, the oil downturn,” Glaser said. “We think these projects are proof that landmark buildings like the Equitable can adapt and still thrive in the market.”