Carbon Positive Hotels: Designing Beyond Carbon Neutral
At a growing number of hotels around the world, travelers will find plaques, signs, and stationary offering official printed declarations identifying the venue as certified “green” or carbon neutral. The venues use different criteria and sanctioning bodies to earn that status, but the main intention is benefiting the environment and the global ecosystem as a whole – while establishing a selling point for conservation-minded travelers.
Still, beyond the immediate ecological curb appeal, creating more environmentally responsible hotels is an ecological necessity. Consider the energy needed to cool or heat hundreds of guest rooms at a given hotel. Take into account the 24/7 operations, the constant departures and arrivals by motor vehicle and the amount of refuse generated by that circulation of guests. The business’ carbon footprint grows exponentially day by day.
The next step in responsible hotel design and construction reaches beyond carbon neutrality and environmental protection in favor of eco system improvement.
According to a report by the United Nations, the hotel industry already accounts for 1% of global emissions – making that accommodation sector the single biggest contributor to global carbon emissions amongst housing types. As the travel industry grows post-pandemic, that percentage is expected to increase.
The next step in responsible hotel design and construction reaches beyond carbon neutrality and environmental protection in favor of eco system improvement. This new breed of carbon positive hotels looks to ensure they’re producing more energy than they’re consuming via responsible construction and offsite planting.
The first carbon positive hotel in the U.S. – Denver’s Populus from developer Urban Villages – is set to open in late 2023. The 265-room hotel will include a rooftop restaurant, bar, retail destinations and event spaces. Designed by AD100 architecture and urban creation firm Studio Gang, Populus will employ sustainable planning and construction features onsite, while planting trees that represent over 5,000 acres of forest offsite.
According to Jon Buerge, Chief Development Officer of Urban Villages, the minds behind the Populus development researched materials that minimized waste, noting more than 60% of materials dumped in landfills come from construction waste. The Denver-based design firm specializes in projects specifically suited to a given neighborhood, while always keeping sustainability in mind. Before Populus, its architects and engineers finished the Sugar Block and Larimer Square projects in Colorado’s capital.
“We’ve opted for low-carbon concrete mixes and high-recycled content materials, while taking steps to minimize the carbon footprint in the transportation of materials,” Buerge says. “We’re also using a very limited amount of finish materials, which helps to decrease the carbon footprint, while keeping the hotel looking sleek and modern.”
Urban Villages worked with STOK, advisors on sustainable built environments, to calculate the hotel’s environmental impact en route to figuring necessary steps to ensure carbon positive status.
“Before we started construction, STOK calculated the carbon footprint of the entire project, including extraction, production, transportation, and construction of every element in the building,” Buerge adds. “We then determined that planting 5,000 acres of trees would sequester that same amount of carbon out of the atmosphere. Not only will we plant more than 70,000 trees, but we are also committed to planting more to offset the energy we consume every day after the hotel opens.”
According to analysis provided by STOK to Urban Villages, the total embodied carbon for the core and shell of Populus will be 4,397 metric tons of CO2e. Materials such as concrete and steel equate to 88% of total carbon. Transportation amounts to 5% of total carbon, while construction adds up to 4%. Finally, end of life (removal of materials into a landfill) registers 3%.
To exceed its carbon footprint toward positive status, STOK and Urban Villages calculate 4,397 MT CO2e is equal to the carbon sequestered by 72,705 trees grown over 10 years; 5,387 acres of forest preserved in one year; and 30 acres of U.S. forests preserved from conversion to cropland within one year. Planning remains underway to ensure Populus will remain carbon positive so the hotel’s overall use (operational carbon) and every guest’s stay will be offset beyond the building’s embodied carbon.
Buerge insists carbon positive planning begins immediately in the conceptual design stages and meets initial challenges in the material selection and construction phases.
“Standard construction often uses steel and concrete, which heavily increases carbon profiles,” Buerge explains. “These are the materials used in parking garages, which is why we decided to eliminate parking – both to reduce Populus’ carbon profile and to show that onsite parking isn’t always necessary as Denver moves towards a more pedestrian-friendly environment.”
According to STOK’s data to Urban Villages, Populus construction uses sustainable, low-carbon concrete mixes and high-recycled content materials. The building’s design was also created to contribute to an energy-friendly concept with windows and a facade designed for self-shading, insulation, and the channeling of rainwater. The public rooftop will feature a garden terrace planted with regional vegetation, naturally cooling the building.
The title of world’s first carbon positive hotel project is claimed by Svart, a Six Senses venue in Norway. Set to open in 2023, the property will operate next to the Svartisen arctic glacier. Hotel Development Director Ivaylo Lefterov reports that development is operating under its own standards for carbon positive construction and operation, using a monitoring tool developed with Net Zero Lab. That international research and technology development firm focuses its work and tools on creating ecologically sustainable systems.
“We are using all-natural low carbon material, focusing mostly on wood, steel, stone, and glass,” Lefterov says. “We limited the usage of low carbon concrete for some specific areas. The entire structure is prefabricated, and the process is controlled because we monitor the sourcing of the raw materials so we know the requirements of our offsets.”
According to Lefterov, the key to carbon positive construction is how material is sourced, where it originates, and how it is finally manufactured. With conventional construction, the biggest carbon contributor is labor, sourcing, and transport. Svart operations maintains local control over its material sourcing.
"Buildings account for 45% of greenhouse emissions in the U.S., so we can’t effectively address climate change without shifting the way buildings are constructed and operated.”
“Using (3D modeling and planning software) Digital Twin, we are able to monitor logistics and control the sourcing of the raw materials and how they are put together on the site,” Lefterov explains. “This allows us to minimize and control the carbon output and the needed offset of that process.”
Between Colorado and Norway, two sets of developers report different cost challenges behind their carbon positive properties. Without outright opening his books, Buerge reports significant money, time, and resources went into the research necessary to calculate the Populus carbon footprint.
“The extra costs and effort are well worth it to combat real estate’s impact on the environment and push the industry towards a greener future,” Buerge says. "Buildings account for 45% of greenhouse emissions in the U.S., so we can’t effectively address climate change without shifting the way buildings are constructed and operated.”
At the Svartisen glacier, Lefterov insists development and construction costs for their carbon positive hotel are no higher than those of building traditional venues.
“With today’s technology, carbon neutral and energy positive buildings are either the same cost or in many cases cheaper (as traditional buildings), especially if one takes into account today’s energy prices and material sourcing,” Lefterov says. “It is just recently that the building industry looked at the wider usage of flat packed prefabricated construction that allows not only the lessening of build time to reduce carbon output, but also the reduction of on-site environmental impact.”
As for operating costs, Buerge explains that Populus is designed with an ultra-insulated exterior envelope to allow the hotel to use less energy while heating and cooling the building. In other words, the hotel’s architecture uses structure and layout to maintain environmental control with less energy spent.
“We are also generating the energy needs of the buildings through a combination of onsite and offsite solar panels, further reducing the carbon footprint,” he adds. “However, the building will still emit carbon through ongoing operations. Once the hotel is open, we will routinely calculate our operational carbon footprint and will offset that impact by continually planting more trees to sequester more carbon than we emit.”
Regardless of cost, Buerge and Urban Villages place their mission emphasis with Denver’s Populus on environmental impact.
“Our metric for success is not just the projects we build, but it’s in leading the entire real estate industry towards a greener future,” Buerge says. “By showcasing that sustainable projects can also be architecturally stunning and economically profitable, we’re laying the groundwork for other developers to replicate.”
At every level of the sustainable hotels effort is the hope that the advancements made in hospitality sector construction will spread to other forms of mass housing such as apartments, dormitories or hospitals.
“Populus is just the first step toward a world where carbon neutral is no longer good enough,” Buerge adds. “Doing the right thing for the planet does not always require compromise. It requires shifting priorities and building a fully aligned team that demands more of ourselves and our industry.”
The Institute for Science & Policy is committed to publishing diverse perspectives in order to advance civil discourse and productive dialogue. Views expressed by contributors do not necessarily reflect those of the Institute, the Denver Museum of Nature & Science, or its affiliates.