Model KPIs
Key Performance Indicators (KPIs) are defined as spatial metrics used to evaluate and compare environmental conditions in urban areas**, in particular outdoor thermal environments**. Each KPI expresses a quantitative assessment of a certain environmental category, based on extracting relating values computed over a given spatial domain (e.g., a neighborhood, park, or plaza, depending on the site area).
All the indicators are calculated by analyzing the percentage of surface area (in m²) that falls within specific metric thresholds - defined basing on literature, referenced case studies, guidelines and expertise - which rely on comfort/discomfort situations. Therefore, these percentages basically represent how much of the total urban area is exposed to beneficial (e.g., comfort zones) or harmful (e.g., heat-stress zones) environmental conditions.
This approach allows planners and designers to map, quantify, and compare the performance of different urban configurations or interventions in promoting thermal well-being.
Wind Speed
Ventilation Assessment
This KPI helps evaluating the natural ventilation potential and wind risk conditions at pedestrian level in urban street canyons.
It describes the percentage of the area (m²) that falls within different ventilation or wind risk categories, divided into three specific “potential” indices.
| KPI | Metric | Metric bins | Description |
|---|---|---|---|
| Stagnation Potential % | Assessment of Pedestrian-level Natural Ventilation Potential in Urban Street Canyons |
| It describes the (%) of (m2) that have values below the accepted threshold for natural ventilation potential |
| Natural Ventilation Potential % | Assessment of Pedestrian-level Natural Ventilation Potential in Urban Street Canyons |
| It describes the (%) of (m2) that have values between the accepted threshold for natural ventilation |
| High Risk Potential % | Assessment of High Risk zones in Urban Street Canyons |
| It describes the (%) of (m2) that have values that exceed the threshold for natural ventilation |
Stagnation Potential It helps identifying areas with very limited air movement at pedestrian level, which can amplify discomfort and pollutant accumulation. It describes the percentage of the area (m²) with wind speeds below accepted thresholds for effective natural ventilation in urban street canyons.
Natural Ventilation Potential It helps evaluating how well pedestrian-level airflow supports thermal comfort and pollutant dispersion. It describes the percentage of the area (m²) with wind speeds at or above thresholds considered acceptable for natural ventilation.
High Wind Risk Potential It helps assessing the wind safety risk in urban canyons for pedestrians and light structures. It describes the percentage of the area (m²) exposed to wind speeds exceeding safety thresholds.
Point-in-Time Wind Comfort
It helps quantifying how comfortable outdoor spaces are for pedestrians at a specific moment in time, based on wind conditions at pedestrian height.
It describes the percentage of the area (m²) that is below the accepted threshold for wind comfort, using activity-based categories from the Lawson criteria.
| KPI | Metric | Metric bins | Description |
|---|---|---|---|
| Pedestrian Comfort % | Assessment of Pedestrian-level Wind Comfort in Urban Street Canyons |
| It describes the (%) of (m2) that have values below the accepted threshold for pedestrian wind comfort |
| Outdoor Use Potential % | Assessment of outdoor use potential in urban spaces |
| It describes the (%) of (m2) that can be used for outdoor activities all year round. |
| Pedestrian Safety Risk % | Assessment of Pedestrian Wind Safety Risk |
| It describes the (%) of (m2) that are above the accepted threshold for pedestrian wind comfort. |
Annual Wind Comfort
It helps quantifying how suitable urban areas are for year-round pedestrian activity by assessing wind conditions across the entire year.
This KPI describes the percentage of the area (m²) that remains within the acceptable threshold for pedestrian comfort during the entire year, defined using activity-based categories from manly worldwide accepted criteria
| KPI | Metric | Metric bins | Description |
|---|---|---|---|
| Annual Pedestrian Comfort % | Assessment of Pedestrian-level Wind Comfort in Urban Street Canyons |
| It describes the (%) of (m2) that have values below the accepted threshold for pedestrian wind comfort |
Thermal Comfort Index
Spatial Variability (Standard Deviation)
It informs on how thermally homogeneous the space is, by detecting hot/cold variations It describes the % of the area (m²) that experiences different levels of spatial temperature variability, based on standard deviation thresholds
| KPI | Metric | Operation Model | Description |
|---|---|---|---|
| High Thermal Variability % | σ > 7°C (Significant thermal contrasts) | Indicates where Temperature Values deviate more than 7ºC from comfort range | It describes the (%) of (m²) that are in ‘High Spatial Variability’ (σ > 7°C from 18-26ºC) |
| Moderate Thermal Variability % | 3°C < σ ≤ 7°C (Microclimatic differences) | Indicates where Temperature Values with noticeable, but moderate, deviations from comfort range | It describes the (%) of (m²) that are in ‘Moderate Spatial Variability’ (3°C < σ ≤ 7°C from 18-26ºC) |
| Low Thermal Variability % | σ ≤ 3°C (Uniform thermal conditions) | Indicates where Temperature Values remain close to the comfort range | It describes the (%) of (m²) that are in ‘Low Spatial Variability’ (σ ≤ 3°C from 18-26ºC) |
Thermal Comfort Statistics
KPI 1 - Heat Stress Indexes
It helps quantifying how exposed the urban environment is to heat stress conditons
It describes the percentage of the area (m²) that experiences heat stress, classified into three levels of heat stress frequency
| KPI | Metric | Operation Model | Description |
|---|---|---|---|
| High Heat Stress Index % | Assessment of High Heat Stress Zones | Spatial filtering of areas mostly exposed to high temperature ranges | It describes the (%) of (m2) that are most of the time within heat-stress levels |
| Frequent Heat Stress Index % | Assessment of Frequent Heat Stress Zones | Spatial filtering of areas frequently exposed to high temperature ranges | It describes the (%) of (m2) that are frequently within heat stress levels |
| Low Heat Stress Index % | Assessment of Low Heat Stress Zones | Spatial filtering of areas occasionally exposed to high temperature ranges | It describes the (%) of (m2) that are less frequently within heat stress levels |
KPI 2 - Thermal Comfort Indexes
It helps quantifying how exposed the urban environment is to thermal comfort conditons
It describes the percentage of the area (m²) that experiences thermal comfort, classified into three levels of thermal comfort frequency
| KPI | Metric | Operation Model | Description |
|---|---|---|---|
| High Comfort Index % | Assessment of High Comfort Zones | Spatial filtering of areas mostly within thermal comfort temperature ranges | It describes the (%) of (m2) that are most of the time within thermal comfort levels |
| Frequent Comfort Index % | Assessment of Frequent Comfort Zones | Spatial filtering of areas frequently within thermal comfort temperature ranges | It describes the (%) of (m2) that are frequently within thermal comfort levels |
| Low Comfort Index % | Assessment of Low Comfort Zones | Spatial filtering of areas occasionally within thermal comfort temperature ranges | It describes the (%) of (m2) that are less frequently within thermal comfort levels |
KPI 3 - Cold Stress Indexes
It helps quantifying how exposed the urban environment is to cold stress conditons
It describes the percentage of the area (m²) that experiences cold stress, classified into three levels of cold stress frequency
| KPI | Metric | Operation Model | Description |
|---|---|---|---|
| High Cold Stress Index % | Assessment of High Cold Stress Zones | Spatial filtering of areas mostly exposed to low temperature ranges | It describes the (%) of (m2) that are most of the time within cold stress levels |
| Frequent Cold Stress Index % | Assessment of Frequent Cold Stress Zones | Spatial filtering of areas frequently exposed to low temperature ranges | It describes the (%) of (m2) that are frequently within cold stress levels |
| Low Cold Stress Index % | Assessment of Low Cold Stress Zones | Spatial filtering of areas occasionally exposed to low temperature ranges | It describes the (%) of (m2) that are less frequently within cold stress levels |
- Knoledge base