Search a city, then Scan Viewport or Draw Area to load buildings from OpenStreetMap. Constraints & Upgrades set the eligibility rules & roof/structure strategy; Design & Material tune carbon, cost & rainfall (auto-filled from the location); the Tree Tool plants greenery.
Toggle shadows, base buildings, extensions & roofs, hover info, and the heat map on or off.
Collapsible categories: Carbon Ledger, Environmental Surfaces (heat & runoff), Co-Benefits & Economics, Materials & Lifecycle, Socio-Urban. Use Save to store a scenario, Optimize to auto-pick the best material + roof for your goal, and Compare to view options side by side.
Colour key for added storeys, ineligible / public buildings, green roofs and solar PV panels.
Resizing this tree will remove nearby tree(s).
Tick the parameters you want the optimizer to vary. It searches every combination and keeps the best for your objective.
12 combinations
No saved scenarios yet.
Configure the model, press Save Scenario, then reopen the comparator.
Densification & Greenery Simulator
Click to add points · drag a point to move it · drag the dashed midpoints to add.
Zoom in to a neighborhood before scanning.
Which existing buildings qualify for an extension.
Pitched/gabled roofs detected from OSM roof:shape or simulated pitch.
How the new vertical addition is built.
Local context — auto-detected when you search a location.
Floor area, residents, economics & socio-urban outcomes.
EC3 / ÖKOBAUDAT official APIs need a token + a small local proxy (browser security). A CDN-hosted factors.json loads directly.
Enter your own factors (kg CO₂e/m³). Changes recalculate the whole ledger live.
Estimates use generic cost / rainfall assumptions (editable on the left & in code constants). Not a substitute for an engineering or financial study.
Timber stores biogenic carbon (a "sink") and ships as pre-fab panels — faster, quieter builds. Values are indicative estimates, not certified EPD data.
Data extrapolated from viewport density of OSM public transit stops (bus, tram, rail).