Hotel Carbon Footprinting: Frequently Asked Question


Questions about the Hotel Carbon Measurement Initiative
(HCMI) (source: HCMI methodology)

  • Why do this?
  • The methodology provides hotels with a carbon footprint per occupied room on a daily basis and per area of meeting space on an hourly basis. The website can then help you calculate the carbon footprint of a specific client’s use of the hotel (i.e. number of room nights and usage of meeting rooms). These are the measures which feedback has suggested the industry will find most useful, particularly for hotels completing Request For Proposals (RFPs) from potential clients.
    The HCMI methodology is aimed for use in all hotel types globally.
  • Why use this website?
  • You can certainly look up up-to-date CO2 emission factors for your region and unit conversion factors and perform the various calculations on your own, but makes this process a lot easier!We also provide additional services for free such as benchmarking of your hotel’s energy consumption and calculations of individual client’s CO2 emissions from staying (and holding meetings) at your hotel. Finally, we can provide assistance and training, as well as independent verification of your data.
  • Who should use this methodology?
  • The methodology is designed to be applied by any hotel around the world. The methodology has been designed in partnership with major hotel groups, however, it applies equally to individual hotels, large and small, regardless of the type of amenities offered.
  • My hotel already report on CO2 emissions?
  • If you do not use HCMI, we recommend switching methodologies immediately as HCMI is the industry-backed approach.If you already use HCMI, then we recommend taking your communications of CO2 emissions to stakeholders one step further by having your data verified by a third party (click here to find out more).
  • Should my calculations be verified?
  • There is no requirement to have your data externally verified. However, obtaining independent verification of your data will increase the impact of your communications with stakeholders (click here to find out more).
  • Which hotel companies were involved in the development of HCMI?
  • Accor, Beijing Tourism Group, Carlson Rezidor Hotel Group, Diamond Resorts International, Fairmont Hotels and Resorts, Hilton Worldwide, Hong Kong & Shanghai Hotels, Hyatt Corporation, InterContinental Hotels Group, Jumeirah Group, Mandarin Oriental Hotel Group, Marriott International Inc, Meliá Hotels International, MGM Resorts International, Mövenpick Hotels & Resorts, Orient-Express Hotels Ltd, Pan Pacific Hotel Group, Premier Inn - Whitbread Group, Starwood Hotels & Resorts Worldwide, Inc., Shangri-La Hotels and Resorts, The Red Carnation Hotel Collection, TUI AG, Wyndham Worldwide. /a>
  • Who are WTTC and ITP?
  • The International Tourism Partnership (ITP), founded in 1992 and part of the International Business Leaders Forum, brings together the world’s leading international hotel companies to provide a voice for environmental and social responsibility in the industry. It works to demonstrate in a very practical way that environmental and social responsibility makes good business sense. ITP does this by highlighting best practice, offering a range of practical products and programmes and tackling emerging sustainability issues through its collaborative working groups. ITP’s programmes and products include, among others, the Youth Career Initiative, the Green Hotelier online magazine, the Environmental Management for Hotels handbook, and Sustainable Hotel Siting, Design and Construction. The combined reach of the membership extends to over 22,000 properties, over 3.2 million rooms and over 1.5 million employees in over 100 countries worldwide.

    The World Travel & Tourism Council (WTTC) is the global authority on the economic and social contribution of Travel & Tourism. It promotes sustainable growth for the industry, working with governments and international institutions to create jobs, to drive exports and to generate prosperity. Travel & Tourism accounts for 255 million jobs globally. At US$6 trillion (9% of GDP) the sector is a key driver for investment and economic growth. For more than 20 years, the World Travel & Tourism Council has been the voice of this industry globally. Members are the Chairs, Presidents and Chief Executives of the world’s leading, private sector Travel & Tourism businesses. These Members bring specialist knowledge to guide government policy and decision-making, raising awareness of the importance of the industry as an economic generator of prosperity. WTTC’s Sustainability Initiative has already concluded a number of projects aimed at driving sustainable economic recovery and growth, namely: the Leading the Challenge on Climate Change report, and ‘Climate Change – A Joint Approach to Addressing the Challenge’.

  • I already report on my carbon emissions. Why use HCMI?
  • HCMI is the first global standardised approach to measuring carbon emissions and the only one approved by the industry.
    Your hotel will be able to improve how it communicates its environmental impacts to customers.

    Currently, approaches to measuring and reporting on carbon emissions vary widely. This can lead to confusion amongst consumers, particularly corporate clients, looking to understand their own potential carbon footprint and meet their own goals/targets in this area In addition, the number and range of methodologies and tools in use make transparency of reporting within the hotel industry a challenge.

  • Does HCMI align with carbon footprinting measurement standards used in other industries?
  • Yes, the methodology was informed by the GHG Protocol Standards. The Greenhouse Gas Protocol (GHG Protocol) is the most widely used international accounting tool for government and business leaders to understand, quantify, and manage greenhouse gas emissions. It has been developed by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD).The HCMI was also developed in partnerships with carbon footprint experts from Cornell University’s Center for Hospitality Research and from KPMG Climate Change & Sustainability practice.
  • How often do I need to calculate my hotel's carbon emissions?
  • The calculations are required to be performed once every reporting year. Some of the data is unlikely to change year on year.
  • How long will this take me?
  • Generally it takes most hotels about 2 hours.
  • What is included in the calculations?
  • The methodology includes all energy used ‘on site’ and includes certain carbon emissions that may arise from ‘off site’ or outsourced activities, most notably outsourced laundry operations (a significant source of emissions and a key area of many hotels’ environmental programmes). The methodology recognises that some hotels operate a number of different facilities and so to improve comparability excludes any emissions from private areas, i.e. private space which is not accessible by guests.
  • What are the outputs?
  • • Carbon footprint per occupied room on a daily basis • Carbon footprint per area of meeting space on an hourly basis • Carbon footprint of a client’s event from the use of multiple guest rooms and meeting rooms. • Benchmarks of your hotel energy consumption against best practice.
  • What is the reporting period?
  • Data is collected and reported for a twelve month period (the reporting period). The methodology allows hotels to have a maximum of six months to prepare their data. After the calculations have been completed, the carbon footprint data is valid for 12 months (the disclosure period). Therefore, the footprint data is never more than 18 months old.

    The diagram below shows how the reporting and disclosure period would work year on year:


    Hotel period Table
  • What data is required?
  • The calculations are required to be performed once a year. This includes an element of standing data, which is unlikely to change year on year, and information that should be updated annually (e.g. energy consumption and number of occupied rooms).

    • Total area of guest rooms and corridors • Total area of meeting facility space • Total number of occupied rooms for reporting year • Total energy consumption for the reporting year. Energy consumption may come from the following sources: o Fuels consumed on-site such as natural gas (stationary combustion), oil and other fuels o Purchased electricity o If applicable, other energy sources such as steam and chilled water, district heating or refrigerants • If the hotel has any private space (area not accessible to hotel guests or conference attendees, e.g. private apartments): Private space are and total conditioned space area• If applicable, outsourced laundry information: i.e. your hotel’s share of energy consumption or your laundry tonnage.

    Total laundry tonnage may be obtained from laundry suppliers or from invoices. Alternatively, a reasonable estimate can be obtained by weighting the average amount of laundry used in a room and multiplying by the number of occupied rooms for the reporting period.


  • How do I obtain energy consumption data?
  • Energy consumption data should be obtained from your energy invoices or from taking meter readings at the beginning and end of the reporting period.

    If you do not have data for the entire year, you may estimate your consumption based on the following estimation techniques:
    • Pro rata estimation: using a proportional method based on actual consumption from another similar period. • Direct comparison: using data that corresponds with a similar period of supply. The advantage of this is that it accommodates variability in energy demand (e.g. gas consumption in winter and summer months). • Price settlement: using the unit price shown on an earlier bill for this billing period or an average price per unit to convert energy costs into consumption data.

  • How are private space treated?
  • Where hotels have areas which are not accessible to hotel guests or conference attendees (e.g. private apartments), the energy consumption for such areas should be subtracted from the total. This is calculated by either:

    • Subtracting the sub-metered energy consumption of the private space (if all energy sources used in the private areas are sub-metered); or
    • Subtracting a percentage of energy consumption based on area apportionment of private space compared to total condition space.

  • Why is outsourced laundry included?
  • Laundry operations can make up 10% of a hotel emissions. Therefore, outsourced laundry is included to allow fair comparison between hotels with in-house and outsourced laundry
  • What are Emission Factors?
  • Emission Factors convert activity data (e.g. energy consumption) to GHG emissions.

    The Emission Factors used by come from reputable, 3rd party source such as the Greenhouse Gas Protocol, the International Energy Agency, the Climate Registry, or national agencies such as the US Environment Protection Agency or the UK Department of Energy & Climate Change.

  • What if my hotel has been refurbished during the year?
  • The methodology calculates GHG emissions during "normal operations”. Conducting extensive refurbishments during the reporting year may falsify the results that will be used in the disclosure period once the refurbishments are completed. Routine refurbishments do not have to be disclosed or accounted for.

    However, hotels undertaking major refurbishments should disclose this information.

  • What about seasonality?
  • We recognise that hotels energy consumption vary by seasons. However, in line with the GHG Protocol, variations in energy consumption and therefore GHG emissions during the year are not taken into consideration. Hotels are asked to provide only one GHG emissions figure per year.
  • Why report on occupied rooms instead of total rooms?
  • The room footprint is intended to communicate the footprint of one night’s stay in a hotel room. Each occupied room shares the proportion of the total footprint equally. The energy used to heat or cool unoccupied rooms is included in the total carbon footprint calculations and allocated to occupied rooms.
  • What if my hotel was closed for part of the year?
  • incorporates in your carbon footprint calculations the number of days that your hotel was open.
  • What if I use energy from renewable sources/green energy?
  • The methodology measures the GHG efficiency at which a hotel provides guest rooms and meeting space to its customers. If the hotel purchases ‘green’ electricity (i.e. electricity at a ‘green’ tariff), it can disclose this information, but it cannot deduct the amount of green electricity used from its total energy consumption.
  • How do I account for onsite renewable energy generation?
  • Onsite renewable energy (e.g. from solar or wind) reduce the amount of energy that a hotel needs to purchase and therefore reduces its energy consumption and carbon emissions.
  • How about carbon offsets?
  • The methodology measures the GHG efficiency at which a hotel provides guest rooms and meeting space to its customers. If the hotel purchases carbon offsets, it can disclose this information, but it cannot deduct the amount of emissions that is offset from its total GHG emissions.
  • How do I know whether my carbon footprint is good or bad?
  • provides a benchmark of your energy consumption against best practice.

    Please note that because some areas or countries have cleaner electricity from the grid. A hotel’s carbon emissions may vary by regions based on carbon emission factors and not energy consumption.

  • What if my competitors have a lower footprint?
  • There could be a number of reasons for this. However, measuring your carbon emissions is the first step in addressing the problem.
  • How can I reduce my energy consumption?
  • We have listed in the Resources section of this website some guidance on how to become more energy efficient.(click here to find out more)
  • How about other environmental issues such as waste, water, product life cycle assessment, food procurement, etc.?
  • These are all important issues, but CO2 emissions is the most common environmental indicator. The HCMI methodology focuses on CO2, however the HCMI Working Group recognises the importance of extending the analysis of hotels’ environmental impacts


    Questions About Carbon Emissions and Climate Change

    (Source: Woodland Trust)

  • What is global warming?
  • Global climate change is caused by many natural processes, such as volcanic activity, forest fires and patterns of solar activity.

    Global climate change is caused by many natural processes, such as volcanic activity, forest fires and patterns of solar activity.

    Since the industrial revolution, humans have been burning increasing quantities of fossil fuels -- oil, coal and gas -- releasing carbon into the atmsophere in the form of carbon dioxide (CO2).

    Carbon dioxide is an important "greenhouse gas" (GHG), which traps more of the sun's energy and causes the atmosphere to heat up. This is the process known as "global warming". Atmospheric levels of carbon dioxide and more potent GHGs have increased sharply in recent decades.

    The environmental impacts of climate change are potentially devastating

    Increasing temperatures affect the weather by altering oceanic and atmospheric currents, and melting glaciers and icesheets. Rainfall can be increased or reduced, as can temperatures (shifting ocean currents can bring colder polar air to a region).

    Scientific predictions in this field are changing very rapidly as our understanding of climate change deepens.

    Climate change is set to accelerate as feedback mechanisms kick in. The action of these mechanisms is the basis for the concept of ecological "tipping points", the triggering of a chain of events that flip an ecosystem from one state to another.

  • What causes climate change?
  • Human activity, in particular the burning of fossil fuels, is now widely considered to be a major cause of global climate change. Urgent action is required to reduce those emissions to limit the long term environmental damage. At the very least they represent an unsustainable way of life -- fossil fuels will by definition run out and we will need to find an alternative, cleaner source of energy.

    There is an overwhelming body of evidence that human industrial activities are having a devastating effect on the natural world. Polar ice sheets and glaciers are melting, pollutants are having a direct impact on many species, and ocean acidifcation is destroying vital coral reef ecosystems upon which the livelihoods of one billion people depend.

  • Could we be wrong about climate change?
  • Climate change skeptics point to colder years, such as 2008, as evidence that the problem is either not real or is going away.

    However, such short term effects are simply part of the natural variation in climate patterns: it is the underlying long term trends that are important.

    That's the difference between the weather and the climate. The weather is the short term pattern of events that give us our day to day conversational topics. The climate is the longer term trend towards a warming planet, together with the increased frequency of extreme events such as hurricanes.

    All the evidence suggests that the long term trend is towards higher mean annual temperatures: global warming and the climate change it brings is indeed very real and is happening now.

  • What is a greenhouse gas?
  • Greenhouse gases (GHGs), such as carbon dioxide (CO2), absorb the sun's warmth, heating the atmosphere. This warm layer of air around the planet acts like a blanket, and is essential for life.

    However, rapid changes in the levels of GHGs – and subsequent rapid changes in the average annual temperature – can lead to more chaotic weather patterns, with extreme events such as hurricanes, droughts and floods increasingly common.

    In order of their effect on the climate, the most important GHGs are carbon dioxide, methane, and nitrous oxide. There are other important GHGs, including chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs). Some GHGs exert far more powerful climate forcing effects, many thousands of times more potently than CO2. While the sheer volume of CO2 being released is the main reason for the apparent focus on carbon, other emissions sources should not be neglected.

    Tackling climate change requires a comprehensive range of activity that includes emissions reduction at source, increased efficiency of essential fossil fuel use, and mitigation of GHG impacts through activities such as woodland creation.

  • What does CO2e mean?
  • Some GHGs are more potent than others. To make it possible to talk about the effect of greenhouse gases in general, the "radiative forcing” – impact on the climate – of each gas is converted into the amount of CO2 required to produce the same effect. CO2 is thus the currency of climate change.

    When talking about greenhouse gas emissions, the convention is to use CO2, or more specifically CO2 equivalent (CO2e). This allows us to describe the warming potential of any greenhouse gas in terms of the equivalent atmospheric warming effect of CO2, effectively a common currency.

    For example, one tonne of methane released into the atmosphere has the same impact on the climate as 23 tonnes of CO2, whereas nitrous oxide is 296 times more potent than CO2.

    A real nasty, such as sulphur hexafluoride -- used in the manufacture of electrical systems -- has 22,200 times the global warming potential of carbon dioxide!

    The unit used is CO2e, meaning carbon dioxide equivalent. Expressing the global warming potential of various GHGs in terms of the amount of carbon dioxide required to produce the same effect makes the impact of differing emissions easier to understand. It also enables a trading system to exist, much as common currencies help economic markets to flourish... or flounder!

    When we talk about reducing our carbon footprint, we really mean reducing our greenhouse gas emissions generally.

  • How does the greenhouse effect work?
  • The atmosphere acts just like a blanket around the Earth through the action of greenhouse gases, which absorb the sun's radiation: without them it would bounce off into space.

    Higher concentrations of GHGs in the atmosphere mean that more solar energy is trapped, so raising the planet’s surface temperature.

    Throughout the Earth's history there have been large changes in the concentrations of various greenhouse gases. These changes, particularly when they have happened over a relatively short period of time, have brought profound changes to all living things. The potential impact of the current rapid rise in GHG concentrations, which has happened since the Industrial Revolution, are a significant cause for concern.

    Feedback processes can enhance the greenhouse effect, a striking example being the melting of the polar ice sheets. The reduced ice cover exposes a much darker surface (water or land), which in turn absorbs yet more heat, speeding the melting process still further. Click on the diagram to the right for a schematic view of the greenhouse effect.

  • What are fossil fuels?
  • Fossil fuels include oil, coal and gas. They are formed over millions of years as layers of organic matter – plant and animal remains – slowly decompose.

    In time, they are buried deep underground where they safely remain until we dig them up. Burning those fuels allows power generation, but also releases huge quantities of CO2 back into the atmosphere.

    By definition, fossil fuels will eventually run out. There has been endless debate over whether or not we have reached "peak oil", the point at which global production peaks.

Business travellers increasingly consider a hotel sustainibility in making their selections and 40% of those surveyed are willing to pay a premium for it.

95% of business travellers believe the hotel industry should be undertaking 'green initiatives.'

(Source: Deloitte)



63% of meeting planners say eco-friendly practices are extremely or somewhat important when choosing a venue

(Source:Survey of almost 400

meeting planners Deloitte)