A Hotel Carbon Baseline: Data to Start With and Claims to Avoid

Decide who the number serves, then draw the boundary

Before collecting anything, decide who will use the figure: your own energy management, a corporate client's RFP for meeting and stay emissions, a lender applying PCAF financed-emissions methods, or a regulator under rules such as the EU CSRD. The purpose fixes the boundary, the scopes you report and how much data assurance you need.

The usual starting point is operational control: include sources the hotel controls in daily operations even if it does not own the building. Use a whole-building approach so guest rooms, restaurants, meeting space, spa and technical areas sit in one inventory rather than fragmented reports that risk double counting or gaps.

• Choose a base year (normally the last full calendar year) and fix it in an internal policy.
• Agree on the consolidation method and data sources before you compute.
• List every building and leased space inside the boundary, including outsourced areas you still control.

The data to start with

A credible baseline is built bottom-up: meter readings and invoices for electricity, natural gas, oil and heat over 12 months, the count of occupied room-nights, the areas of guest rooms and meeting space, the volume of outsourced laundry and a log of refrigerant top-ups. The HCMI methodology treats exactly these items as the inputs for a hotel's carbon footprint.

The most common first-year mistakes are counting only electricity and forgetting gas, leased generators and vehicles, or skipping refrigerant leaks — which for some properties form a significant share of direct emissions. Begin with what already sits in invoices and accounting systems, and clearly label any estimate as an assumption.

• 12 months of energy: all fuels and purchased electricity, steam, heat and cooling from meters or bills.
• Occupied room-nights and revenue data, used for apportionment and cross-checks.
• Areas: guest rooms, meeting/function space and total building area.
• Outsourced laundry volumes, where applicable.
• Refrigerant top-up log and data on any owned fleet or mobile equipment.

Scopes 1, 2 and 3 in hotel terms

Scope 1 covers direct emissions from sources the hotel owns or controls: fuel burned in on-site boilers and generators, owned vehicles and refrigerant leaks from HVAC systems. Scope 2 covers indirect emissions from the electricity, steam, heat and cooling the hotel purchases.

Under the GHG Protocol's Scope 2 Guidance, hotels must report two figures: location-based, using the average emission factor of the national or regional grid, and market-based, reflecting contractual purchases of renewable energy. To use the market-based method, the contract (for example a green tariff or energy attribute certificate) must meet the eight scope 2 quality criteria; otherwise the renewable claim does not belong in the inventory.

A hotel's scope 3 is dominated by purchased goods and services such as food and outsourced laundry, fuel-and-energy-related activities, waste, guest and staff transport, and — for chains — franchised operations. Add these categories only after scopes 1–2 are solid.

• Scope 1: boilers, generators, owned fleet, refrigerant leaks.
• Scope 2: purchased electricity, heat, steam and cooling — report location- and market-based.
• Scope 3: procurement, outsourced laundry, waste, travel, franchisee emissions.
• For corporate buyers, hotels typically share scope 1–2 plus outsourced laundry, as HCMI does.

Normalize into metrics, then benchmark

Absolute tonnes matter for reporting, but managing a property and comparing it with peers works better through intensity: emissions per occupied room-night and per area of meeting space per hour. These are exactly the metrics the Hotel Carbon Measurement Initiative produces — a methodology created in 2012 by the Sustainable Hospitality Alliance (then ITP) and the WTTC with 23 hotel companies and WRI review, updated in 2016 and 2022 and used by more than 30,000 hotels.

The Cornell Hotel Sustainability Benchmarking (CHSB) index collects the same intensity data: its 2025 edition, covering the 2023 calendar year, drew on 27,219 hotels in the final global dataset for energy, water and carbon. Compare yourself only with hotels of a similar climate, class and type, using data from the same reporting year.

• Metrics: tonnes CO2e per occupied room-night; tonnes CO2e per m² of meeting space per hour.
• The denominator is actually occupied rooms, not the room inventory.
• Check methodologies before comparing: HCMI figures and an internal chain report are not interchangeable.
• CHSB publishes medians and ranges — work with the range, not a single benchmark.

What you can support, and claims to avoid

A defensible public statement reads: 'Scope 1–2 emissions for 2025 were X tonnes CO2e, down Y% from the 2023 baseline, with occupancy up Z%.' It rests on measured data and a named base year, so it can be verified and repeated next season.

Without verification, avoid 'carbon-neutral hotel', 'net zero', '100% green energy' and 'zero carbon per room-night'. Such wording requires either certified market-based instruments for scope 2 or verified reduction plus compensation, and it risks being treated as greenwashing in several jurisdictions. Treat this as general guidance, not legal advice: requirements differ by country, and rules in the EU under CSRD differ from voluntary disclosure elsewhere.

• Safe to say: tonnes CO2e by scope, intensity per room-night, change against a named base year.
• Avoid: 'neutral', 'net zero', 'emission-free' and 'green hotel' without a stated method and verification.
• Disclose the base year, the method (market vs. location-based) and the boundary — transparency is what builds trust.