Detailed List of Example Indicators

Life Expectancy

Average life expectancy for inhabitants  

World Health Organization (WHO), World Health Statistics 2024: Monitoring Health for the SDGs (Geneva: WHO, 2024).

Resident Retention Rate

Duration of residence in district 

Gehl Institute, Inclusive Healthy Places: A Guide to Inclusion and Health in Public Spaces (Copenhagen: Gehl Institute, 2018).

Resident Satisfaction 

Resident satisfaction survey

Gehl Institute, Inclusive Healthy Places.

Modal Split of Journey to Work  

Ratio of residents who take public transport, walk or bike to work  

Nicholas Martino, Cynthia Girling and Yuhao Lu, "Urban form and livability: socioeconomic and built environment indicators", Buildings and Cities 2.1 (2021): 220–243.

Air Quality 

Annual average air quality index  

WHO, WHO Global Air Quality Guidelines (Geneva: WHO, 2021).

Surface Water Quality 

Proportion of wastewater generated on-site that is treated before release

DataDrivenEnviroLab, "Urban Environment and Social Inclusion Index" (UESI), n.d.

Safe Drinking Water 

Age-standardised disability-adjusted life-years (DALYs) lost per 100,000 persons due to exposure to unsafe drinking water 

Environmental Performance Index, “Unsafe drinking water" data, available at https://epi.yale.edu/measure/2024/UWD.

Ambient Noise Level 

% of residential area exceeding 55 dB(A) Lden threshold 

European Environment Agency, Environmental Noise in Europe—2020, EEA Report 22/2019 (Luxembourg: Publications Office of the European Union, 2020). 

Green Amenity Access 

Year on year change in % of population living within 400-m walking distance of a park or green space 

Lena Chan et al., Handbook on the Singapore Index on Cities' Biodiversity (also known as the City Biodiversity Index (CBI) (Montreal: Secretariat of the Convention on Biological Diversity and Singapore: National Parks Board, Singapore, 2021), Indicator 13, 26.

Urban Redevelopment Authority (URA), A Green & Liveable City: Singapore Urban Design Guidebook (Singapore: URA, 2015), 1.1.2. 32–50.

Income Equity (Gini) 

Gini coefficient of household income distribution within district (0–1) 

United Nations (UN) Human Settlements Programme (UN-HABITAT), Guidelines for Reporting the Implementation of the New Urban Agenda, revised ed. (Nairobi: UN Habitat, 2024).

Employment Rate 

% of working-age population (15–64) in employment within the district 

Organisation for Economic Co-operation and Development, (OECD), Implementation toolkit of the OECD Principles on urban policy, OECD Regional Development Papers, 31 (Paris: OECD Publishing, 2022).

Gehl Institute, Inclusive Healthy Places.

Local Business Diversity 

Shannon entropy index of business establishment types per district 

Martino, Girling and Lu, “Urban form and liveability”.

Ground Floor Activation 

% of ground floor frontage in active use (retail, F&B, community) 

Gehl Institute, Inclusive Healthy Places.

Urban Heat Reduction 

Year-on-year change in mean land surface temperature (°C)  

John Patrick Connors, Christopher S. Galleti and Winston T.L. Chow, “Landscape configuration and urban heat island effects: assessing the relationship between landscape characteristics and land surface temperature in Phoenix, Arizona”, Landscape Ecology 28 (2013): 271-283.

Flood Risk Exposure 

% of district area within modelled 1-in-100-year flood zone 

Intergovernmental Panel on Climate Change (IPCC), “Small Islands”, in Climate Change 2022—Impacts, Adaptation and Vulnerability, Working Group II Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge and New York: Cambridge University Press 2022), 2043-2121.

Annual Runoff Volume Control Rate 

The percentage of rainfall retained and reused on-site

Mark Randall et al., "Evaluating Sponge City volume capture ratio at the catchment scale using SWMM", Journal of Environmental Management 246 (2019): 745–757.

Water Stress Indicator

Ratio of freshwater reserves to population size (per capita) 
 

Malin Falkenmark, Jan Lundqvist and Carl Widstrand, "Macro-scale water scarcity requires micro-scale approaches", Natural Resources Forum 13.4 (1989): 258–267.

Urban Greenness Indicator 

Area-averaged (mean) NDVI [may also include peak NDVI, annual mean NDVI, population-weighted peak NDVI, and population-weighted annual mean NDVI] 

Jennifer D. Stowell et al., “Development of a global urban greenness indicator dataset for 1,000+ cities”, Data in Brief 48 (2023): 109140.

Plant Species Richness 

Count of native vascular plant species per standard survey area 

Chan et al., CBI Indicator 4.

Bird Species Richness 

Count of native bird species recorded per standard survey period 

Chan et al., CBI Indicator 5.

Soil Retention  

Water erosion of soil in tonnes/ha/year

Panos Panagos et al., “How the EU Soil Observatory is providing solid science for healthy soils”, European Journal of Soil Science 75.3 (2024): e13507.

Habitat Restoration 

(Area of habitat restored in year) / (area of degraded habitat) × 100% 

Chan et al., CBI Indicator 5.

United Nations Environment Programme, Convention on Biological Diversity, “Decision Adopted by the Conference of the Parties to the Convention on Biological Diversity: 15/4. Kunming-Montreal Global Biodiversity Framework”, 19 December 2022.

Civic Participation Rate 

Number of urban community resident associations

Robert Osei-Kyei et al., “Critical review of urban community resilience indicators”, Smart and Sustainable Built Environment 13.6 (2024): 1511–1537.

Social Cohesion Index 

Standardised survey questions for measuring interpersonal trust and institutional trust, with a core module of five questions using 0–10 scales

OECD, OECD Guidelines on Measuring Trust (Paris: OECD Publishing, 2017), Annex 2, 196–211.

Local Environmental Stewardship Indicator 

Survey across seven action categories, quantifies stewardship of the environment by members of the local community

John W. Turnbull, Emma L. Johnston and Graeme F. Clark, “LESI: A quantitative indicator to measure local environmental stewardship”, MethodsX 7 (2020): 101141.

Total GHG Intensity

Total tCO₂e (Scope 1+2) / resident population per year

World Resources Institute, C40 Cities and ICLEI, Global Protocol for Community-Scale Greenhouse Gas Inventories: An Accounting and Reporting Standard for Cities, Version 1.1 (Washington, DC: World Resources Institute, 2021).

Scope 1: Stationary Combustion

tCO₂e from stationary fuel combustion within district boundary per year

Scope 1: In-boundary Transport

tCO₂e from in-boundary transportation per year

Scope 1: Agriculture Forestry and Other Land Use Change

tCO₂e from AFOLU in boundary per year

Scope 1: Industrial Processes

tCO₂e from IPPU in boundary per year

Scope 1: In Boundary Waste and Wastewater Emissions

tCO₂e from in-boundary Waste and Wastewater treatment per year

Scope 2: Grid-supplied Energy

tCO₂e from purchased grid electricity and heat per year

Land Use Compactness

Moran's I spatial autocorrelation index of built-up density across the district

Amnon Frenkel and Maya Ashkenazi, “Measuring Urban Sprawl: How Can We Deal with It?”, Environment and Planning B: Urban Analytics and City Science 35.1 (2008): 56–79.

Miriam Steurer and Caroline Bayr, “Measuring urban sprawl using land use data”, Land Use Policy 97 (2020): 104799.

Water Consumption Intensity

Annual daily average of potable water consumption / resident population (litres/capita/day)

Mohit Arora et al., “Assessing water circularity in cities: Methodological framework with a case study”, Resources, Conservation and Recycling 178 (2022): 106042.

Indicator

Method of Calculation

Key References

Waste Recycling Rate

% of total municipal solid waste diverted from landfill through recycling or reuse per year

Carolin Bellstedt et al., CityLoops: Urban Circularity Assessment Method, Deliverable 4.4, 1 (CityLoops, 2022).

Building Reuse Rate

% of construction permits for renovation/adaptive reuse vs. new construction per year

David Cheshire, Regenerative by Design: Creating Living Buildings and Cities (London: RIBA Publishing, 2024).

Local Food Production

% of total food consumption (by weight) sourced from within the city or peri-urban region

Chan et al., CBI Indicator 14.

Gross Plot Ratio

Total gross floor area / site area

Martino, Girling and Lu, “Urban form and liveability”.

Population Density

Resident population / site area

Robert I. McDonald et al., “Denser and greener cities: Green interventions to achieve both urban density and nature”, People and Nature 5.1 (2023): 84–102.

Impervious Surface Coverage

% of site area covered by impervious surfaces

McDonald et al., “Denser and greener cities”.

Chan et al., CBI Indicator 10.

Stanford University, Urban Flood Risk Mitigation, InVest User Guide.

Skyview Factor (SVF)

Average SVF for 10m samples across the district (SVF is the ratio of the visible sky area of a point in space to the total sky area)

Chunping Miao et al., "Review of methods used to estimate the sky view factor in urban street canyons", Building and Environment 168 (2020): 106497.

Frontal Area Density (FAD)

Average FAD for the district across 200x200m samples

C.S.B. Grimmond and T.R. Oke, "Aerodynamic properties of urban areas derived from analysis of surface form", Journal of Applied Meteorology 38.9 (1999): 1262–1292.

Proportion of Natural Areas in the City

(Total area of natural, restored and naturalised areas) ÷ (Area of city) × 100%

Chan et al., CBI Indicator 1.

Convention on Biological Diversity, Kunming-Montreal Global Biodiversity Framework (GBF), “2030 Targets (with Guidance Notes)”, n.d., Targets 2, 3.

Protected Natural Area

(Area of protected or secured natural areas) / (total district area) × 100%

Chan et al., CBI Indicator 8.

GBF, “2030 Targets”, Target 3.

Matthew Selinske et al., “Biodiversity needs both land sharing and land sparing”, Nature 620 (2023): 727.

Tree Canopy Coverage

% of site area covered by tree canopy (from NDVI satellite data)

McDonald et al., “Denser and greener cities”.

Shared Green Space Plot

% of site area in shared human–nature use (parks, gardens, green roofs)

Thomas Schröpfer, Dense + Green Cities (Basel: Birkhäuser, 2020).

WOHA and bioSEA, Designing for Biodiversity: The Value of Nature Centric Design (Singapore: WOHA, 2024).

Green Plot Ratio

Weighted Leaf Area Index total / site area (unitless)

Boon Lay Ong, “Green plot ratio: an ecological measure for architecture and urban planning”, Landscape & Urban Planning 63.4 (2003): 197–211.

Land Use Diversity

Shannon entropy index of land use types within site boundary

Martino, Girling and Lu, “Urban form and liveability”.

Housing Typology Mix

Shannon entropy of dwelling unit types (by size/tenure) within district

Ground Floor Use Mix

Count of distinct ground floor use categories per 100-m of street frontage

Gehl Institute, Inclusive Healthy Places.

Habitat Biodiversity Value

Biodiversity value score calculated as the product of habitat size, condition, conservation priority and strategic significance, expressed in biodiversity units. Habitat types classified using the IUCN Global Ecosystem Typology.

Ramboll, Global Biodiversity Metric (GBM): Launched at UN COP16, Cali, 2024, adapted from Natural England Biodiversity Metric 4.0.

Tree Species Diversity

Shannon entropy index of tree species from municipal tree inventory

Chan et al., CBI.

Indicator

Method of Calculation

Key References

Landscape Element Diversity

Count of distinct landscape elements (planter, green wall, pond, etc.) / site area

WOHA and bioSEA, Designing for Biodiversity.

Key Services Index

Average network distance to school, clinic, and retail centre (m)

Centre for Liveable Cities (CLC), Building Liveable and Sustainable Cities: A Framework for the Future (Singapore: CLC, 2025).

Martino, Girling and Lu, “Urban form and liveability”.

Walkability Index

Composite of intersection density, average block length, and land-use entropy within 400m buffer

Lawrence D. Frank et al., "The development of a walkability index: application to the Neighborhood Quality of Life Study", British Journal of Sports Medicine 44.13 (2009): 924–933.

Rail Transit Access

Network distance to nearest rail/MRT station (m)

Martino, Girling and Lu, “Urban form and liveability”.

CLC, Building Liveable and Sustainable Cities.

Bus Network Access

Network distance to nearest bus stop (m)

Cycling Infrastructure Access

Network distance to nearest dedicated cycling path (m)

Ecosystem Connectivity

Betweenness centrality of nearest landscape patch (spatial network analysis)

Darrel Chin Fung Tiang et al., “Ecological connectivity in fragmented agricultural landscapes and the importance of scattered trees and small patches”, Ecological Processes 10, 20 (2021).

Effective Mesh Size

Area-weighted mean of unfragmented landscape patch sizes (ha)

Megan R. Deslauriers et al., “Implementing the connectivity of natural areas in cities as an indicator in the City Biodiversity Index (CBI)”, Ecological Indicators 94.2 (2018): 99–113.

Chan et al., CBI Indicator 2.

Access to Nature

Network distance from residential parcel to nearest park or nature area (m)

Chan et al., CBI Indicator 13.

URA, A Green & Liveable City.

Ecological Corridor Length

Total length of dedicated ecological corridors (km)

Richard T.T. Forman, Land Mosaics: The Ecology of Landscapes and Regions (Cambridge: Cambridge University Press, 1995).

Green Mobility Co-location

% of active mobility network (walking/cycling) co-located with green corridor or park connector

Kiat W. Tan, “A greenway network for Singapore”, Landscape and Urban Planning 76 (2006): 45–66.