Is your sustainable hotel really ‘net zero’? Almost certainly not – most forget to mention embodied carbon
- Embodied carbon encapsulates all the harmful greenhouse gases emitted during the renovation and construction of a building, a huge part of any hotel’s footprint
- Few truly net-zero hotels exist; London’s Room2 Chiswick is arguably one, a prime example of sustainable transparency
Behold the American hotel of the future: it’s free of plastic bottles, anti-fossil fuel and powered entirely by renewable energy.
A renovation project, it gives new life to existing structures of concrete and steel, and reuses door frames, light fixtures and even tile. All of its guest rooms are decorated with locally made furnishings upholstered in sustainably sourced fabrics.
It’s rated LEED Platinum – one of just about a dozen hotels in the United States to claim the green certification programme’s highest rank. And it’s the first US hotel to receive Passive House designation, granted to buildings that meet stringent net-zero energy requirements.
When the Hotel Marcel opened in New Haven, in the state of Connecticut, in May, it checked all those boxes as part of a mission to be the first hotel in the US with net-zero carbon emissions. But for all of the ways in which the Marcel makes real efforts to be a green marvel, it missed one huge consideration: embodied carbon.
Embodied carbon is the term that encapsulates all the harmful greenhouse gases emitted during the renovation and construction of a building – an outsize part of any project’s footprint.
The Marcel’s triple-glazed windows? Good for keeping heating and cooling costs down, but a massive carbon emitter to manufacture. The hotel’s new, more efficient mechanical systems? They, too, emit large amounts of carbon during fabrication, transportation and installation.
Demolition of old walls? More carbon. Plasterboard, interior finishes and bath fixtures for all 169 rooms? Carbon, carbon, carbon – all ignored in the Marcel’s net-zero promise.
“The net-zero objective is for operations,” the project’s architect Bruce Becker acknowledges.
Given that hotel operations use more energy than virtually any other type of building – including those for offices, retail, housing and manufacturing – and account for an estimated 1 per cent of global carbon emissions, net-zero operations are an admirable goal and a good example of the progress that properties are making in day-to-day greening.
Renewable energy, reusable water and zero-waste policies also happen to save money on a month-by-month basis.
Embodied carbon in construction – contributing to at least 21 per cent of global emissions, according to consulting firm Brightworks Sustainability – is hardly a whisper amid the noise, if it’s mentioned at all, especially given how frequently hotels renovate compared with other types of large buildings.
Hilton Worldwide, for instance, which manages more than 500 hotels around the world (including the Marcel), publishes an annual sustainability report that follows environmental, social and governance (ESG) criteria. Yet its most recent report, released in 2020, didn’t mention embodied carbon once in its 72 pages of data and pledges.
Considering that the Hilton brand opened 40 new hotels in 2020, that’s a lot of unaccounted carbon.
Four Seasons Hotels, Marriott International, Hyatt Hotels and other big brands have also announced goals to reduce emissions over the coming three decades, but those pledges have remained largely, if not entirely, focused on operational carbon via reductions in fossil-fuel use, waste and water usage.
“It’s fine to be hyperbolic about being the most luxurious hotel in the world – that’s subjective – but when you are talking about carbon emissions, that’s a real, quantitative thing with real effects,” says John Locke, an architect and senior principal research scientist at software firm Autodesk who studies approaches to net-zero building.
“Those kinds of inflated statements about very real things that impact the world shouldn’t be taken so lightly.”
Aurora Jensen, a project manager and materials specialist at Brightworks Sustainability, which helps clients choose the most sustainable construction materials and calculates their embodied and operational carbon footprints, agrees.
“When a lot of these hotels say they are net-zero, they don’t necessarily understand the claim they are making,” she says. Without any regulation or agreed-upon definition of what it means to be net zero, she adds, everything is open to interpretation – and sometimes, obfuscation.
That may come as a shock to the 81 per cent of people who, according to the Sustainable Travel Report 2022 released by travel agency Booking.com, say that sustainability is an important factor in determining how they travel.
Here are a few further points to consider before booking your next hotel – and a few great resorts that are truly getting it right.
Be sceptical of carbon offsets
One way many hotels reach so-called net-zero status is through offsets, an unregulated and unstandardised practice that, at best, sequesters a hard-to-verify amount of carbon from the atmosphere – and, at worst, actually contributes to emissions.
All too often, they are viewed as a make-good for even the worst building practices. Why bother sourcing more expensive concrete aggregates or renewable timber when you can build another steel-and-glass marvel and just buy a few thousand dollars’ worth of credits?
“The carbon that a building emits is very real, but those phantom offsets may not necessarily be,” Locke says.
That said, not all offsets are worthless. Even Jensen, who is openly sceptical of these programmes, concedes that well-vetted offset programmes can compensate for a carbon footprint that’s already been minimised by other, more effective means.
Don’t fall for meaningless certifications
With no real definition of net zero, buildings of all kinds have long relied on certifications – such as those from LEED – to back up their green assertions. Google now showcases 29 of these certifications in its search results, which is intended to help travellers make informed, sustainable choices. But those designations can be misleading and even dishonest.
Take Alight, a new booking platform that assigns sustainability ratings to hotels. It requires hotels only to submit self-reported data, which allows a 540-room resort with six restaurants on Hawaii’s Kohala Coast to score higher than an eight-room renovated hacienda in Mexico that runs on solar power. Other organisations simply require payment for endorsement.
Even LEED (Leadership in Energy and Environmental Design), the long-time authority on sustainable building, is guilty of exhibiting some questionable judgment.
In 2021, it awarded the US$4.3 billion Resorts World Las Vegas, owned by Malaysia’s Genting Group, a gold certification, the organisation’s second-highest rating. Yet it’s hard to imagine anything less green than 3,500 air-conditioned guest rooms, a 5.5-acre pool complex and thousands of LED panels blasting larger-than-life video content in the middle of the Mojave Desert.
A closer look at Resorts World Las Vegas’s LEED scorecard revealed zero points in several key categories, including green power, rapidly renewable materials, recycled content and material reuse.
Other resources such as the Green Hotels Association and the Global Sustainable Tourism Council – both of which are endorsed by the US Environmental Protection Agency – purport to distil environmentally friendly travel with simple lists or rankings.
While many of these organisations are fuelled by good intentions, it’s important that travellers look beyond basic certifications and ratings to understand what metrics are being used to make these claims. If something sounds dubious, it probably is.
Scrutinise the architecture and design
One way to identify hotels that produce less atmospheric carbon: look for designs made from natural and renewable materials such as timber. With low embodied carbon that can often be sourced nearby, it actually sequesters carbon dioxide.
For instance, the Wood Hotel at Sara Kulturhus in Skelleftea, Sweden, is part of a nearly all-timber structure that is expected to naturally offset millions of pounds of carbon over its life.
Timber continues to store the carbon sequestered throughout its growth in perpetuity – even after it has been felled – accounting for a significantly smaller embodied carbon footprint. It’s a big step in the right direction, as are other biomaterials such as bamboo.
Eventually, Locke says, new breakthroughs will allow architects to design buildings that produce little to no embodied carbon at all. Low-carbon biomaterials, such as concrete alternatives that use bacteria growth as a bonding agent, are encouraging innovations that experts hope to see replace traditional construction materials during the coming decade.
Until then, projects that rely heavily on reuse and renovations, like the Marcel, will remain one of the best, most attainable solutions to creating greener hotels. “Renovating or repurposing an already existing building will almost always be the more sustainable approach,” Locke says.
In addition to the Marcel, the Madrona, in Healdsburg, in the US state of California, is a recent renovation project that exemplifies why reuse is such a successful way to reduce emissions. For every new wall that wasn’t built, every steel frame that wasn’t erected, and every window that was reused, embodied carbon was decreased.
The Madrona even went so far as to recycle dozens of pieces of antique furniture and art from the inn’s previous owners – giving new life to what might have otherwise ended up in a landfill.
Transparency is key
To date, few hotels that have made net-zero statements have released data supporting those claims.
“Anyone who tells you that it’s not possible to calculate embodied carbon data is either misled or misleading you,” Locke says. “While it may take more time and effort to collect this information, anybody who claims to care about the environment should be making it a priority.”
While consumers can’t be expected to demand CO2 statistics from the hotel concierge, they can vote with their wallets at hotels like London’s Room2 Chiswick, a prime example of sustainable transparency.
The 86-room property claims to be the first hotel in the world to achieve whole-life carbon net zero. It has emissions calculations to back up that factor in both operational and embodied carbon, including the hotel’s construction period, and estimates for its eventual demolition.
Property developer Lamington, which owns and operates the hotel, produced an internal 34-page report this year that outlined a companywide goal to neutralise all of its property emissions by 2030 through a combination of greener construction, renewable energy sources, zero-waste operations and verified offsets.
The hotel’s initial embodied carbon emissions of 2,448 metric tonnes have already been offset by EcoPlanet Bamboo, a reforestation project in Nicaragua; emissions from future renovations will be addressed as they happen.
“Despite our best efforts to continue to reduce our operational and embodied carbon, we will still have unavoidable emissions, which need to be offset with a verified project,” says Robert Godwin, Lamington’s managing director, who visited EcoPlanet Bamboo’s reforestation sites this year.
The future of green hotels
Two other soon-to-open hotels are ambitiously chasing legitimate net-zero status.
In northern Norway, at the foot of the Svartisen glacier, Svart has for years drawn notice for claims that it will be an energy-positive, carbon-neutral property when it opens in 2024.
The hotel, which recently joined the Six Senses brand, will achieve energy positivity through a large solar array, a waste heat recovery system, and “other innovative technologies”, according to Jeff Smith, Six Senses’ vice-president of sustainability. Surplus energy will be fed back into a local grid for consumption by surrounding communities.
Smith says that the hotel does not plan to purchase offset credits and will rely instead on its surplus energy to make up for any emissions. Still, when it comes to the project’s carbon footprint, the data appears to be based solely on operational emissions; net-zero embodied carbon remains a vague, undefined ambition.
“Six Senses Svart is still in the early design stage of development,” Smith says. “Innovative technology and materials are being evaluated, and we look forward to sharing more details on those as they come.”
Property developer Urban Villages is pushing carbon claims even further, aiming to make its soon-to-open Populus the world’s first carbon-positive hotel (counter-intuitively, this means that it will have a negative carbon footprint).
To lower its construction emissions, the 265-room property in Denver, in the US state of Colorado, will use a low-carbon concrete mix made without cement, limewash plaster that sequesters carbon, high-recycled-content materials, and minimal finishes.
Colorado-based consulting firm Stok is undertaking the process of calculating the project’s total embodied carbon, based on materials, transportation, construction and demolition – currently expected to be 4,397 metric tonnes of CO2.
Urban Villages chief executive Grant McCargo believes that it will be offset by the planting of 72,705 trees across more than 5,000 acres of forest in vetted sites from Maine in the US to the Amazon rainforest.
“This was my first time tackling the embodied carbon footprint in a project, and it’s pretty amazing what you can calculate,” McCargo says. “The quickest and easiest solution to those emissions is to just go and buy a bunch of offset credits, but we wanted to be more involved in the process to ensure that this is really being done right.”
Though his mission remains a vision yet to be realised, McCargo says he’s received several calls from other hotel groups aiming to reach the same goals.
“I don’t have all the answers,” he says. “But we are committed to finding out and sharing with everybody else.”