
8 hotels in London hold Green Key certification. Each one is audited by an outside body, on a schedule it does not set itself.
Wikimedia CommonsDoubletree by Hilton LondonThis full-service upscale hotel is located in downtown London, Ontario. It features spacious guest rooms and comprehensive meeting facilities, servingIndependently certified
Wikimedia CommonsDelta London ArmouriesHistoric upscale hotel in downtown London, housed in a unique former armory building. Features elegant accommodations, an indoor pool, and extensive eIndependently certifiedGreen Key audits a hotel against roughly 100 criteria, some mandatory and some scored, covering water and energy use, waste separation, cleaning chemicals, food sourcing and staff training. A hotel applies, documents each criterion, and is then visited on site. Certification runs for one year, so a hotel keeps it only by re-submitting evidence and passing another visit. It is the largest scheme in this catalogue and the one you will meet most often across Europe.
Green Key measures management practice, not carbon. A large hotel with a pool and air conditioning can hold the certificate while using far more energy per guest than an uncertified guesthouse down the road — it is being judged on whether it manages its resources deliberately, not on the size of its footprint. The scoring is also weighted towards documentation, so a hotel with good records can outscore one that quietly does better.