!['A jewelry box': Mainspring finishing midcentury Uptown office renovation 1 P7112026 scaled](https://businessden.com/wp-content/uploads/2024/07/P7112026-scaled.jpg)
Mainspring founder Fiona Arnold sits in the company’s office on the third floor of The Sudler, an Uptown office building that her firm repositioned. (Thomas Gounley/BusinessDen)
Standing outside the Uptown office building her firm has been renovating, Fiona Arnold notes the white paint, and the gold rings that are being installed across the exterior.
“I think the whole thing is going to look like a jewelry box up here on the hill,” she said.
The Denver-based development firm Arnold founder, Mainspring, bought the three-story, 28,000-square-foot office at 1576 Sherman St. in Denver in July 2021, paying $5.6 million.
At the time, Arnold estimated her firm would spend another $6 million to take the building down to its studs, and reposition it with a midcentury feel. Three years later, the work is almost done, but Arnold and Mainspring CEO Andy Schlauch said they’ve ended up spending more than twice that, about $13 million.
!['A jewelry box': Mainspring finishing midcentury Uptown office renovation 2 image002 1](https://businessden.com/wp-content/uploads/2024/07/image002-1-300x155.jpg)
A rendering of The Sudler. (Courtesy Mainspring)
What that money has bought them, Arnold believes, is a building and a distinct aesthetic that will make employees want to spend time in the office.
“Our idea with the office is to be very hospitality-driven,” Arnold said.
The building at the southeast corner of Sherman and 16th, a block from the state Capitol, was constructed around 1960 for Daly Insurance Co. Mainspring has rebranded the building “The Sudler,” after the architect who designed it. James Sudler also designed the castle-like Denver Art Museum North Building in collaboration with Italian modernist architect Gio Ponti.
After purchasing the building, which had been used by a coworking firm and a lobbyist, Mainspring took the structure down to its concrete shell and built it in a midcentury-modern style.
The 10 office suites in the building, which range from 550 to 5,000 square feet, feature custom walnut and floor-to-ceiling curved glass walls that let in ample light. The units are being leased fully furnished, with furniture sourced from RiNo’s Studio Como and art sourced by Kate Finds Art. There are curtains installed on all the windows, and a record player in each unit, complete with a starter set of vinyl.
As companies aim to get employees back in the office, Arnold said, “it has to be an experience that they’ll look forward to.”
No tenants have committed to the building, although Mainspring itself is already operating out of the largest unit. The company is offering flat monthly rents, starting at $2,800 for the smallest unit, which has four desks and a small sitting area with a couch, chair and rug. A shared kitchen is just outside, although some of the larger units have a kitchen within them.
“That prices very favorably compared to WeWork,” said CEO Schlauch.
Mainspring is open to short-term leases — as little as three months — and even partial-week leases, for companies sticking to a Tuesday-Thursday office schedule or something similar. “No one’s done it before,” Arnold said, but Mainspring would likely charge a daily rate for such an arrangement.
It’s a significant bet on office space at a moment when total office vacancy downtown is above 30 percent. Across the street is Capitol Center, one of a handful of office buildings whose owners have submitted plans for a residential conversion in recent years.
The rings being installed on the building harken to its original sunshade that wrapped the building, although the modern version is purely aesthetic and not intended to block the rays.
!['A jewelry box': Mainspring finishing midcentury Uptown office renovation 13 7.28D Sherman original](https://businessden.com/wp-content/uploads/2021/07/7.28D-Sherman-original.png)
An old photo shows the original facade on the 1576 N. Sherman St. building. (Courtesy photo)
The lobby will house the third location of Blue Sparrow Coffee, which Mainspring owns and operates. It will likely open next month, joining locations on Platte Street and in Backyard on Blake, an office-and-retail complex that Mainspring developed in RiNo.
Downstairs, in the basement, there’s a fitness center that will be open to the public and managed by Littleton-based Elevation Health, with a discount for tenants. The aesthetic extends to that space. Curtains frame the mirrors on the wall. The artwork at the entrance is of women eating nachos.
Arnold said she’s not a fan of the term “amenity,” oft used by landlords. To her, it implies an imitation that falls short.
“If you’re going to have a gym, make it a real gym, run by people who manage gyms,” she said. “If you’re going to have coffee, make it a real coffee shop.”
Mainspring currently has three of its other real estate holdings listed for sale: a former firehouse in Curtis Park, as well as land along Washington Street and Welton Street in Five Points. Prior to the pandemic, Mainspring had proposed building a hostel on the Welton site.
None of those sites are under contract to be sold, Arnold and Schlauch said, and Mainspring listed them largely to test the market. While the company decided the 0.7-acre Washington Street parcel is “too big” for the small firm, Mainspring may still redevelop the firehouse at 3201 Curtis St. and the Welton site itself.
“If we get this leased up and cash flowing, we’d love to do the firehouse,” Arnold said of The Sudler.
Gensler was the architect on The Sudler renovations. Sprung Construction was the general contractor.
!['A jewelry box': Mainspring finishing midcentury Uptown office renovation 1 P7112026 scaled](https://businessden.com/wp-content/uploads/2024/07/P7112026-scaled.jpg)
Mainspring founder Fiona Arnold sits in the company’s office on the third floor of The Sudler, an Uptown office building that her firm repositioned. (Thomas Gounley/BusinessDen)
Standing outside the Uptown office building her firm has been renovating, Fiona Arnold notes the white paint, and the gold rings that are being installed across the exterior.
“I think the whole thing is going to look like a jewelry box up here on the hill,” she said.
The Denver-based development firm Arnold founder, Mainspring, bought the three-story, 28,000-square-foot office at 1576 Sherman St. in Denver in July 2021, paying $5.6 million.
At the time, Arnold estimated her firm would spend another $6 million to take the building down to its studs, and reposition it with a midcentury feel. Three years later, the work is almost done, but Arnold and Mainspring CEO Andy Schlauch said they’ve ended up spending more than twice that, about $13 million.
!['A jewelry box': Mainspring finishing midcentury Uptown office renovation 2 image002 1](https://businessden.com/wp-content/uploads/2024/07/image002-1-300x155.jpg)
A rendering of The Sudler. (Courtesy Mainspring)
What that money has bought them, Arnold believes, is a building and a distinct aesthetic that will make employees want to spend time in the office.
“Our idea with the office is to be very hospitality-driven,” Arnold said.
The building at the southeast corner of Sherman and 16th, a block from the state Capitol, was constructed around 1960 for Daly Insurance Co. Mainspring has rebranded the building “The Sudler,” after the architect who designed it. James Sudler also designed the castle-like Denver Art Museum North Building in collaboration with Italian modernist architect Gio Ponti.
After purchasing the building, which had been used by a coworking firm and a lobbyist, Mainspring took the structure down to its concrete shell and built it in a midcentury-modern style.
The 10 office suites in the building, which range from 550 to 5,000 square feet, feature custom walnut and floor-to-ceiling curved glass walls that let in ample light. The units are being leased fully furnished, with furniture sourced from RiNo’s Studio Como and art sourced by Kate Finds Art. There are curtains installed on all the windows, and a record player in each unit, complete with a starter set of vinyl.
As companies aim to get employees back in the office, Arnold said, “it has to be an experience that they’ll look forward to.”
No tenants have committed to the building, although Mainspring itself is already operating out of the largest unit. The company is offering flat monthly rents, starting at $2,800 for the smallest unit, which has four desks and a small sitting area with a couch, chair and rug. A shared kitchen is just outside, although some of the larger units have a kitchen within them.
“That prices very favorably compared to WeWork,” said CEO Schlauch.
Mainspring is open to short-term leases — as little as three months — and even partial-week leases, for companies sticking to a Tuesday-Thursday office schedule or something similar. “No one’s done it before,” Arnold said, but Mainspring would likely charge a daily rate for such an arrangement.
It’s a significant bet on office space at a moment when total office vacancy downtown is above 30 percent. Across the street is Capitol Center, one of a handful of office buildings whose owners have submitted plans for a residential conversion in recent years.
The rings being installed on the building harken to its original sunshade that wrapped the building, although the modern version is purely aesthetic and not intended to block the rays.
!['A jewelry box': Mainspring finishing midcentury Uptown office renovation 13 7.28D Sherman original](https://businessden.com/wp-content/uploads/2021/07/7.28D-Sherman-original.png)
An old photo shows the original facade on the 1576 N. Sherman St. building. (Courtesy photo)
The lobby will house the third location of Blue Sparrow Coffee, which Mainspring owns and operates. It will likely open next month, joining locations on Platte Street and in Backyard on Blake, an office-and-retail complex that Mainspring developed in RiNo.
Downstairs, in the basement, there’s a fitness center that will be open to the public and managed by Littleton-based Elevation Health, with a discount for tenants. The aesthetic extends to that space. Curtains frame the mirrors on the wall. The artwork at the entrance is of women eating nachos.
Arnold said she’s not a fan of the term “amenity,” oft used by landlords. To her, it implies an imitation that falls short.
“If you’re going to have a gym, make it a real gym, run by people who manage gyms,” she said. “If you’re going to have coffee, make it a real coffee shop.”
Mainspring currently has three of its other real estate holdings listed for sale: a former firehouse in Curtis Park, as well as land along Washington Street and Welton Street in Five Points. Prior to the pandemic, Mainspring had proposed building a hostel on the Welton site.
None of those sites are under contract to be sold, Arnold and Schlauch said, and Mainspring listed them largely to test the market. While the company decided the 0.7-acre Washington Street parcel is “too big” for the small firm, Mainspring may still redevelop the firehouse at 3201 Curtis St. and the Welton site itself.
“If we get this leased up and cash flowing, we’d love to do the firehouse,” Arnold said of The Sudler.
Gensler was the architect on The Sudler renovations. Sprung Construction was the general contractor.