Design a Cooler, Greener and Energy Efficient Neighbourhood
A neighbourhood-scale digital twin to test interventions before spending millions
Current Twekkelerveld Condition
Why Twekkelerveld?
- Mixed building stock → retrofit tradeoffs are real.
- Heat + energy affordability collide here.
- Perfect scale: neighbourhood interventions actually measurable.
Neighbourhood Hotspots
Location details
Learn from international examples on cooling, energy, retrofits and community solar.
Now
Hotter summers, rising bills.2027
Grid pressure + retrofit targets.2030
Policy deadlines (EU targets).2050
Climate baseline shift.Predefined Scenarios
Current Digital Twin Situation
Location details
- Cooler summers and improved health through more trees and green roofs
- Lower utility bills thanks to rooftop solar and deep retrofits
- Progress towards climate targets with lower CO₂ emissions
- Greater resilience and social equity for the neighbourhood
Cost–benefit calculation explained
Cost–benefit scores allow you to compare different aspects of the scenario on a common 0–100 scale. The total project cost is divided by your selected budget and multiplied by 100. Space use is normalised in the same way against the available space budget. The benefit score is the arithmetic mean of greenness, cooling, energy savings, CO₂ reduction and a health score. Normalisation aligns values with different units to a common range and is typically applied before averaging.
The health score draws on evidence linking green space and well‑being. A scoping review found that a 25 % increase in neighbourhood tree canopy was associated with a one‑point decrease on the 5‑point Depression Anxiety and Stress Scales (DASS). Another study reported that spending 10–50 minutes in natural spaces improved mood, focus and physiological markers like blood pressure and heart rate. Both trees and green roofs therefore contribute to the health benefits shown in this dashboard.
For formal definitions of net present value (NPV) and benefit–cost ratio (BCR), and other underlying formulas, see the Equations & assumptions section below.
Sources: Wikipedia – Normalization (statistics); Urban Trees & Human Health; Spending time in nature reduces stress.
Equations & assumptions
Energy cost: (gas consumption × pricegas) + (imported electricity × priceelec) − (exported electricity × feed‑in tariff).
CO₂ savings: (baseline energy − new energy) × emission factor.
Benefit–cost analysis: Net present value (NPV) = Σ (cash flow ÷ (1 + discount rate)year) − capital cost; Benefit–cost ratio (BCR) = NPV of benefits ÷ NPV of costs.
Tree carbon sequestration: Each additional tree is assumed to absorb ~10 kg of CO₂ per year and provides shade and cooling benefits.
Green roofs & vegetation: Vegetation and green roofs help cool buildings and neighborhoods by shading surfaces, deflecting solar radiation and releasing moisture.
PV costs: High‑efficiency PV modules are about €0.115 per Wp; the slider's default of €5,400 per +1 % PV capacity is based on typical installed costs.
Default parameter values: Tree cost €350 per tree; PV cost €5,400 per +1 % capacity; retrofit cost €12,000 per dwelling; green roof cost €8,000 per +10 % roof coverage.
Health benefits: Exposure to trees and green spaces is linked to better mental and physical health. A scoping review reported that a 25 % increase in neighbourhood tree canopy correlated with a one‑point decrease on the 5‑point Depression Anxiety and Stress Scales (DASS) [study]. Researchers at Cornell University found that spending 10–50 minutes in natural spaces improved mood, focus and physiological markers like blood pressure and heart rate [study]. The health score used in this dashboard assumes that both additional trees and green roofs contribute equally to these wellness benefits.
These formulas and assumptions show how ecological (trees, green roofs) and energy (PV, retrofits) interventions interact. More trees and green roofs increase greenness and reduce urban heat, while PV and insulation reduce energy use and emissions. The combined scenario score weighs these co‑benefits against investment and space budgets over your selected time horizon.
Sources: Investopedia – NPV formula; Investopedia – BCR; One Tree Planted – tree CO₂ absorption; US EPA – heat‑island benefits of vegetation; Rinnovabili – PV module prices.