Lisbon: Dataset Overview

This page documents the dataset used in articles referencing Green Key Certified Hotels in Lisbon.
It provides the source, scope, boundary definitions, and interpretation context for city-level certification figures cited in published research.

This dataset exists to support verification and comparability, not hotel selection or ranking.

Data Source

Green Key International — Certification Registry
Administered by the Foundation for Environmental Education (FEE)

The Green Key registry provides hotel-level certification status and validity periods but does not include performance metrics such as emissions, energy use, or operational outcomes.

City Definition

For the purposes of this dataset, Lisbon refers to Lisbon city proper, as defined by the municipal boundary.

The following are excluded from this dataset:

  • hotels located in surrounding metropolitan municipalities

  • properties in Greater Lisbon recorded under different city names

  • regional or suburban accommodations outside the Lisbon municipality

This boundary definition is used consistently across all comparative analysis to avoid inflating counts through metropolitan spillover.

Certification Count (December 2025)

  • Green Key certified hotels: 61

  • Distinct properties: 61

  • Certification validity: All listings valid into 2026 or later

No weighting is applied by hotel size, room count, or brand portfolio.

Population Baseline

  • Lisbon municipality population: 544,851
    (2021 national census, most recent stable municipal baseline)

Per-capita normalization is used in comparative analysis to contextualize scale, not to rank cities.

Interpretation Notes

Green Key certification is interpreted in this research as a baseline sustainability signal, indicating that a hotel meets the programme’s environmental management criteria at the time of certification.

Certification presence:

  • ✔ indicates participation in a recognized sustainability framework

  • ✖ does not indicate absolute environmental performance

  • ✖ does not measure carbon footprint, transport emissions, or supply-chain impacts

The absence of certification is not assumed to indicate weak sustainability practices, particularly in contexts where regulation or urban form may substitute for voluntary labels.

Methodological Context

City-level certification figures are interpreted using:

  • municipal boundaries

  • per-capita normalization

  • urban density and transport context

Full assumptions and limitations are documented in:

  • Methodology & Assumptions

  • Research Desk

This ensures that Lisbon’s certification density is evaluated relative to context, not in isolation.

Limitations

This dataset does not include:

  • hotel-level carbon or energy data

  • Scope 3 emissions

  • operational performance indicators

  • real-time certification updates

Figures represent a snapshot based on registry data available in December 2025.

Independence & Use

Hotel inclusion does not imply endorsement, ranking, or commercial relationship.

This dataset is intended to:

  • support verification of published analysis

  • enable transparent comparison

  • provide methodological clarity

It is not intended for booking decisions or consumer recommendations.

Related Research

  • 10 Hotels with Green Key Certification in Lisbon: What to Actually Expect (2026 Guide)

  • Green Key Certified Hotels in Porto: Adoption Without Saturation (2026 Guide)

  • Green Key Certified Hotels in Madrid and Barcelona: Why Fewer Certifications Can Mean Deeper Scrutiny (2026 Guide)

← Back to Research Desk

Download

  • lisbon_green_key_city_2025.csv

  • lisbon_green_key_city_2025.xlsx

“dataset only — no interpretation”.

Final confirmation

✔ This page is a dataset page, not an article
✔ No rankings, lists, or promotional language
✔ Fully aligned with your Lisbon article
✔ Safe for citation by journalists and analysts