One Night in the Self-Proclaimed "First U.S. Carbon-Positive Hotel"

Welcome to One Night In, a series about staying in the most unparalleled places available to rest your head.

My first reaction upon being invited to Denver’s Populus, which claims to be the country’s first "carbon-positive" hotel, for a press trip overlapping with its October ribbon-cutting, was, admittedly, one of skepticism. After all, the transport, construction, and hospitality industries are among the most damaging to the environment, and the 265-room hotel, designed by award-winning firm Studio Gang and developed by Urban Villages, covers all those bases. In recent years, "ecotourism" has been appropriately criticized—in fact, the now-ubiquitous term "greenwashing" for the marketing practice of deceptive corporate environmental claims originated from the hospitality industry itself: In 1983, environmentalist Jay Westerveld got the idea for the concept after visiting a Fiji hotel that asked guests to reuse their towels to "reduce ecological damage" while the property was in the middle of expanding. Therefore, the irony was not lost on me that the place purporting to be the first "carbon-positive" hotel in the U.S. would fly out 10 journalists on commercial jets for a brief media trip. (The irony is also not lost on me that I, someone who purports to care deeply about climate change, readily accepted said invitation.)

To interrogate Populus’s claim, we must first parse the term a bit further. The messaging of "carbon positive," a newer, less definitive term than "carbon neutral," is a bit murky. While carbon neutral means that any carbon emitted into the atmosphere from an activity is balanced by an equivalent amount removed through offsets or absorption, carbon positive (also called climate positive or, confusingly, carbon negative) refers to an entity that goes beyond carbon neutrality to create an environmental benefit by removing more carbon from the atmosphere than it emits. In its press materials, Populus defines carbon positive as a "commitment to sequester more carbon in biomass and soil than the combined embodied and operational footprints of the building throughout its entire lifecycle." (Note the use of "commitment.")

Though Populus did report to be actually carbon positive at opening, there are two methods of measuring to consider: embodied carbon, which refers to the greenhouse gas emissions from the materials and construction of a building, and operational carbon, meaning the emissions associated with the energy used to operate a building. The hotel said its initial purchase of 7,000 million tonnes of carbon dioxide equivalent (mTCO2e) of certified carbon credits, in combination with the more than 70,000 new trees planted as part of its robust reforesting program with the U.S. Forestry Service, and its use of 100 percent renewable electricity from Colorado wind farms, offset its 6,675 mTCO2e of embodied carbon. Whether it can remain carbon positive operationally remains to be seen.

Still, there are inherent problems in focusing solely on carbon as a metric for measuring climate impact, in no small part due to the fact that the carbon credit market is an unregulated mess. Populus was intentional in seeking out certified, U.S.-based credits from partner organizations Grassroots Carbon, OneTreePlanted, and Terrapass, but Urban Villages CEO John Buerge acknowledges that carbon emissions aren’t the end-all-be-all of a building’s environmental impact. "Carbon ultimately became kind of the easiest or most consistent metric for us to judge performance across all aspects of the building," Buerge says. "[But] when you look at the impact of real estate, it’s not just about the carbon released and the impact on climate change. It’s also about how the real estate industry is significantly affecting our ecological diversity."

During my stay, I did my best to pin down whether the hotel really lives up to its claims to have a net-positive impact on the environment, in whatever myriad ways that can be calculated.

Monday

11:30 a.m.: Populus’s opening date has been pushed back several months, which means that when the 10 of us descend on the hotel for our October press trip, it’s the day before it even officially opens. I arrive at a 13-story white wedge rising adjacent to Denver’s Civic Center Park. Populus is a striking building; fluted concrete pocketed with oval windows of varied sizes. (Some Denverites have nicknamed it the "cheese grater," which the Populus team, to their credit, has taken in stride). The facade’s defining visual feature is the patchwork of lidded eye–shaped windows intended to evoke the marks left on the bark of Aspen trees (Populus tremuloides) by the lower branches they shed while growing.

My first question before I even set foot inside, is, why, particularly for a building with aims to be carbon positive, was the much less carbon-intensive option of adaptive reuse—which both Studio Gang and Urban Villages have utilized for other projects—not pursued? In a phone call after my stay at Populus, Buerge tells me: "Absolutely the most sustainable building is the one you don’t have to build. But we also believe strongly that dense and vibrant urban environments are critical parts of a sustainable future." The hotel’s downtown location—the former site of Colorado’s first gas station and, at the time of construction, a vacant lot—was critical to Urban Villages’ goal of revitalizing the area, but building right in the heart of Denver meant that the project also had to contend with existing city code and laws that can be out of pace with climate goals. For example, Populus had to seek out a variance from the city of Denver to not include any on-site parking, instead taking advantage of nearby existing, often-underutilized office parking lots for its valet service.

Another immediately confusing design choice was the building material: concrete, one of most carbon-intensive materials on the planet. (Its primary ingredient, cement, makes up nearly eight percent of the world’s total carbon emissions.) The concrete used for Populus is the proprietary ECOPact low-carbon mix by Holcim, which claims to have 30 percent lower carbon emissions compared to standard concrete. But why use concrete at all—particularly when mass timber, for example, is more sustainable, and often more durable?

On the phone, Buerge tells me timber was considered as an alternate material for the exterior. "We spent the first year in our design process trying to get entitled a mass-timber-built structure," he says. But the existing building code did not allow timber for a 13-floor structure and the city was ultimately not comfortable issuing a variance. In the last year, however, perhaps spurred by the pressure from Populus, the city adjusted its code to allow for a future mass-timber build at that height. However, Buerge adds: "The reality is that mass timber can be a much more sustainable material than steel and concrete, but it can also be much worse if you’re not sourcing the timber in a sustainable way." Anything at scale, and without proper regulation, can be deleterious.