Hotel API

Calculate CO2e emissions for hotel accommodation based on country-specific factors.

<div class="admonition admonition-tip"><span class="admonition-icon">💡</span><div class="admonition-content"><p>Complete Trip Emissions Pair the Hotel API with the <a href="/docs/api/travel">Travel API</a> for complete business trip emissions (Scope 3 Category 6). Transport + accommodation in two API calls.</p> </div></div>

Endpoints

Endpoint Description
GET /v1/hotel/emissions Calculate emissions for a stay
GET /v1/hotel/factors List all country factors
GET /v1/hotel/compare Compare countries

Calculate Emissions

<span class="api-method api-method-get">GET</span> /v1/hotel/emissions

Parameters

Parameter Type Required Default Description
country string Yes - Country code (ISO 3166-1 alpha-2)
nights integer Yes - Number of nights (1-365)
rooms integer No 1 Number of rooms (1-100)
equivalents boolean No false Include real-world equivalents

Example Request

curl "https://api.emissions.dev/v1/hotel/emissions?\
country=GB&\
nights=3&\
rooms=1" \
  -H "Authorization: Bearer em_live_xxxxxxxxxxxx"

Example Response

{
  "data": {
    "type": "hotel_emission",
    "id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
    "attributes": {
      "emissions": {
        "co2e": 94.5,
        "co2e_unit": "kg",
        "co2e_grams": 94500,
        "per_night_kg": 31.5,
        "per_room_night_kg": 31.5,
        "source_trail": [
          {
            "data_category": "emission_factor",
            "name": "Hotel stay - United Kingdom",
            "source": "DEFRA",
            "source_dataset": "Greenhouse gas reporting: conversion factors 2025",
            "year": "2025",
            "region": "GB"
          }
        ]
      },
      "stay": {
        "country_code": "GB",
        "country_name": "United Kingdom",
        "nights": 3,
        "rooms": 1,
        "total_room_nights": 3
      },
      "factor": {
        "value": 31.5,
        "unit": "kg CO2e per room per night",
        "is_estimate": false
      }
    }
  },
  "meta": {
    "methodology": "DEFRA 2025 / Cornell CHSB Index",
    "emission_factors_year": 2025,
    "calculated_at": "2026-02-07T14:30:00Z"
  }
}

List Factors

<span class="api-method api-method-get">GET</span> /v1/hotel/factors

Get all available country emission factors. Results are sorted by emissions (lowest first).

Example Response

{
  "data": [
    {
      "country_code": "CR",
      "country_name": "Costa Rica",
      "factor": 4.7,
      "unit": "kg CO2e per room per night",
      "region": "Central America"
    },
    {
      "country_code": "SE",
      "country_name": "Sweden",
      "factor": 5.1,
      "unit": "kg CO2e per room per night",
      "region": "Northern Europe"
    }
  ],
  "meta": {
    "total_countries": 60,
    "source": "DEFRA 2025 / Cornell CHSB Index"
  }
}

Compare Countries

<span class="api-method api-method-get">GET</span> /v1/hotel/compare

Compare hotel emissions across multiple countries.

Parameters

Parameter Type Required Description
countries string Yes Comma-separated country codes (2-10)
nights integer No Number of nights (default: 1)
rooms integer No Number of rooms (default: 1)

Example Request

curl "https://api.emissions.dev/v1/hotel/compare?\
countries=GB,FR,DE,SE&\
nights=5" \
  -H "Authorization: Bearer em_live_xxxxxxxxxxxx"

Example Response

{
  "data": [
    {
      "country_code": "SE",
      "country_name": "Sweden",
      "total_kg": 25.5,
      "per_room_night_kg": 5.1,
      "savings_vs_highest_kg": 132,
      "savings_vs_highest_percent": 83.8
    },
    {
      "country_code": "FR",
      "country_name": "France",
      "total_kg": 41,
      "per_room_night_kg": 8.2,
      "savings_vs_highest_kg": 116.5,
      "savings_vs_highest_percent": 74
    },
    {
      "country_code": "DE",
      "country_name": "Germany",
      "total_kg": 139,
      "per_room_night_kg": 27.8,
      "savings_vs_highest_kg": 18.5,
      "savings_vs_highest_percent": 11.7
    },
    {
      "country_code": "GB",
      "country_name": "United Kingdom",
      "total_kg": 157.5,
      "per_room_night_kg": 31.5,
      "savings_vs_highest_kg": 0,
      "savings_vs_highest_percent": 0
    }
  ],
  "meta": {
    "nights": 5,
    "rooms": 1,
    "lowest_emissions": "SE",
    "highest_emissions": "GB"
  }
}

Country Emission Factors

Hotel emissions vary dramatically by country:

Lowest Emissions

Country Factor (kg/night) Why
Costa Rica 4.7 99% renewable electricity
Sweden 5.1 Hydro + nuclear
Norway 6.8 Hydroelectric
France 8.2 Nuclear power

Highest Emissions

Country Factor (kg/night) Why
Maldives 152.2 Diesel generators
South Africa 89.3 Coal-heavy grid
Australia 67.8 Coal + gas
China 58.9 Coal-dominant

Complete Trip Emissions

Combine with the Travel API for full business trip emissions:

# Flight: London → Dubai return
curl "https://api.emissions.dev/v1/travel/emissions?\
origin_country=GB&origin_location=London&\
destination_country=AE&destination_location=Dubai&\
transport_mode=flight&return_trip=true" \
  -H "Authorization: Bearer em_live_xxxx"

# Hotel: 4 nights in UAE
curl "https://api.emissions.dev/v1/hotel/emissions?\
country=AE&nights=4" \
  -H "Authorization: Bearer em_live_xxxx"

# Sum co2e values for total trip emissions
# Both report GHG Protocol Scope 3 Category 6

What's Included

The emission factors account for:

  • Electricity consumption (lighting, appliances)
  • Heating and cooling (HVAC)
  • Hot water heating
  • Common area energy use
  • Laundry services

Not included: Guest transportation, room service food, minibar contents.