Copenhagen is one of the easiest major cities in which to find a genuinely sustainable hotel — not because of marketing, but because most of its rooms are independently certified. As of 2022, roughly 68% of the city's hotel rooms held an official eco-certification, and the most trusted of those labels, Green Key, was itself invented in Denmark. This guide explains which certifications actually mean something, where the greenest neighbourhoods are, how to get around without a car, and exactly what to check before you book.
By the IMPT Hotels editorial team · Updated 2026-05-29
Copenhagen has spent more than a decade building the infrastructure that makes a low-impact stay practical rather than aspirational. In 2012 the City Council adopted the CPH 2025 Climate Plan, an attempt to become the world's first carbon-neutral capital. The plan reorganised the city around district heating, wind and biomass power, energy-efficient buildings and car-free mobility.
The headline 2025 deadline was not met. In 2022 the city acknowledged it would miss the target after the ARC waste-to-energy plant in Amager became ineligible for national carbon-capture funding — the technology that was meant to absorb the city's last remaining emissions. Officials now talk about reaching neutrality later in the decade and contributing positively to the climate by 2035. It is an honest reminder that even leading cities fall short, and that travellers should look at verified performance rather than slogans.
Even so, the groundwork is real and visible to any visitor. Around 45% of Copenhageners cycled to work or school in 2023, supported by roughly 397 km of dedicated bike paths. About 98% of households are connected to district heating, and in 2023 wind and solar generated some 63% of Denmark's national electricity consumption. That clean, shared infrastructure is the reason a Copenhagen hotel can run a genuinely low-carbon operation in the first place.
The single most useful thing a traveller can do is treat "eco-friendly" as meaningless on its own and look instead for a named, third-party certification. In Copenhagen three labels dominate, and all three are credible.
Green Key is the one to know first, partly because it was born here. It began as a Danish initiative created by the hospitality association HORESTA together with VisitDenmark before expanding worldwide under the Foundation for Environmental Education (FEE). It has since grown into the most widespread tourism eco-label on the planet — by the end of 2025 it covered more than 8,300 certified establishments across about 90 countries, a jump of roughly 25% in a single year. A Green Key award is renewed annually and audited against criteria covering energy, water, waste, food, cleaning chemicals, staff engagement and guest communication.
The Nordic Swan Ecolabel is the most demanding of the three and is the official environmental label of the Nordic countries. It assesses a property's whole footprint — energy and water limits, waste, responsible procurement, the use of other eco-labelled products, food-waste prevention and biodiversity — against dozens of mandatory requirements. Fewer hotels hold it precisely because the bar is higher. ISO 14001, an international environmental-management standard, is the third common mark and signals that a hotel runs a documented, continuously improving environmental system rather than one-off green gestures.
In Copenhagen these labels often stack: some chains hold Green Key on every city property and add Nordic Swan or ISO 14001 on top. Where you cannot verify a specific label, treat the green claim as unconfirmed.
You do not have to stay in a single "eco district" to travel sustainably in Copenhagen, because the transport system does much of the work. The driverless Metro runs frequently, the train and bus network is dense, and the airport is a short Metro ride from the centre — there is rarely a reason to rent a car.
For a low-impact base, the central districts of Indre By (the old town), Vesterbro and Nørrebro put you within walking or short cycling distance of most sights, which cuts the transport footprint of a trip more than almost any hotel feature. Vesterbro and Nørrebro in particular are dense, walkable and full of independent, plant-forward restaurants. The Ørestad and harbour-front areas showcase the city's newer sustainable architecture and sit directly on the Metro.
Cycling is the defining Copenhagen experience and the lowest-impact way to move. Most neighbourhoods have protected bike lanes, and many hotels lend or rent bikes; the city's bike-share scheme is another option. A striking example of how deep the green infrastructure runs: roughly a third of Copenhagen's hotel rooms — more than 8,000 — are cooled using cold seawater drawn from the harbour rather than conventional air conditioning, cutting the related CO2 by up to about 70%.
The gap between a hotel that is sustainable and one that merely says so is almost always visible in the details. Use the points below to separate substance from spin before you reserve.
Start with the certification, then look past it: a credible green hotel will name a renewable-energy source or district-heating connection, run measurable water and energy reduction, operate a serious food-waste and recycling programme, and avoid single-use plastics. Plant-rich menus and local sourcing are good signs; so is transparency about what the property has not yet solved.
Be alert to greenwashing. A linen-reuse card and a few low-energy bulbs are baseline housekeeping, not a sustainability strategy. Vague phrases such as "eco-conscious" with no third-party label, no figures and no named scheme should lower your confidence, not raise it.
Finally, consider how the booking itself is handled, since a stay's footprint extends beyond the building. IMPT Hotels (impthotels.com) is one option that books at the same price as booking direct while directing a portion of each booking toward climate projects certified to standards such as the Verra Verified Carbon Standard and the Gold Standard — a way to pair a certified green hotel with verified climate funding. Whichever route you choose, the principles are the same: confirm a real certification, prioritise a central, walkable or cyclable location, and favour properties that publish numbers rather than adjectives.
Same price as booking direct — and a share of your booking funds verified climate projects (Verra VCS & Gold Standard).
Find carbon-neutral hotels →Yes. Green Key began as a Danish initiative created by the hospitality association HORESTA together with VisitDenmark, and is now run internationally by the Foundation for Environmental Education (FEE). By the end of 2025 it covered more than 8,300 certified establishments across roughly 90 countries, making it the most widespread tourism eco-label in the world.
As of 2022, about 68% of Copenhagen's hotel rooms held an official eco-certification, and around 58% of the city's hotels were certified under Green Key, an ISO standard or the Nordic Swan Ecolabel. That is among the highest concentrations of certified rooms of any major European city.
Not yet. The city set out to be the world's first carbon-neutral capital by 2025 under its CPH 2025 Climate Plan, but in 2022 it acknowledged it would miss that target after carbon-capture funding for the local waste-to-energy plant fell through. Officials now aim to reach neutrality later in the decade and to contribute positively to the climate by 2035.
Of the labels common in Copenhagen, the Nordic Swan Ecolabel is generally the most demanding, assessing a hotel's entire environmental footprint against dozens of mandatory requirements. Green Key is the most widespread and is renewed and audited annually, while ISO 14001 certifies that a property runs a documented, continuously improving environmental-management system.
Look for a named third-party certification rather than vague phrases like "eco-conscious." Credible hotels will state a renewable-energy or district-heating source, publish water and energy figures, and run real food-waste and recycling programmes. Treat a towel-reuse card or a few low-energy bulbs as routine housekeeping, not proof of a sustainability strategy.