ORU Density Map

Interactive choropleth map of Oxford neighbourhood density for ORU door-knocking planning. Visualises any per-neighbourhood numeric dataset (e.g. HMO counts, amenity density, survey responses) on LSOA boundaries with optional point markers.

Quick start

View the map here

Want to run it locally?

cd oru_doorknocking_map
python3 -m http.server 8000
# Open http://localhost:8000

For detailed setup, data generation, and testing instructions see INSTRUCTIONS.md.

What the map shows

Oxford is divided into LSOA neighbourhoods (Lower Layer Super Output Areas — small census zones). Each LSOA is colour-coded from light to dark based on a numeric value. By default the map shows OSM amenity counts as a structural placeholder.

Upload an HMO CSV (in-browser, no data leaves your machine) and the map instantly updates to show HMO density per LSOA, with individual HMOs highlighted as building footprint polygons matched to their exact address in OpenStreetMap.

Feature	Description
Neighbourhood choropleth	LSOA polygons filled light to dark by value (quantile scale)
HMO building footprints	Blue outlines of matched HMO buildings (after CSV upload)
Fallback markers	Orange circles at postcode centroid for unmatched addresses
Amenity markers	Blue circles at each amenity location (placeholder mode)
Hover info	Neighbourhood name, count, and label on polygon mouseover
Building tooltips	Address, licence dates, register ID on HMO building hover
Colour legend	Auto-generated quantile breakpoints in bottom-right corner
Layer control	Toggle layers independently
CSV upload panel	Drag-and-drop or click; data stays in memory only, never cached
Placeholder disclaimer	Banner at top; updates when HMO data is loaded

Uploading HMO data (in-browser)

Use the Upload HMO CSV panel in the bottom-left corner. Your CSV should have these columns (header names are detected by fuzzy match):

Column	Description
ID	HMO register reference
Address	Full address including postcode (e.g. 18 Abbey Road, OX2 0AE)
Street	Street name
Licence start	HMO licence start date
Licence end	HMO licence end date

The browser matches each address to an OSM building footprint and assigns it to an LSOA via the postcode. No data leaves your machine — all reference data is pre-generated and served as static files. CSV data is never cached or persisted; it lives only in browser memory for the current session. Click Clear HMO data or refresh the page to revert to the placeholder view.

Data

Regenerating placeholder data from OSM

python3 scripts/generate_placeholder.py

Regenerating building footprint + postcode data

Must run after generate_placeholder.py (needs data/neighbourhoods.geojson):

python3 scripts/generate_building_data.py

This produces:

• data/oxford_buildings.geojson (~10 MB) — building footprints with address tags
• data/postcode_lsoa.csv (~50 KB) — postcode-to-LSOA mapping

See INSTRUCTIONS.md for full details.

File structure

oru_doorknocking_map/
  index.html                    <- HTML file (Leaflet + chroma + PapaParse via CDN)
  static/
    app.js                      <- map logic, layer builders, upload UI wiring
    hmo-upload.js               <- CSV parsing, address matching (in-memory only)
  data/
    neighbourhoods.geojson      <- Oxford LSOA boundary polygons (from ONS)
    amenities.geojson           <- individual point markers (from Overpass)
    placeholder_amenities.csv   <- per-neighbourhood counts (placeholder)
    oxford_buildings.geojson    <- building footprints with address tags (from Overpass)
    postcode_lsoa.csv           <- postcode -> LSOA + centroid mapping
  scripts/
    generate_placeholder.py     <- regenerate LSOA + amenity data from ONS + Overpass
    generate_building_data.py   <- regenerate building footprints + postcode mapping
  requirements.txt              <- Python dependencies for data-generation scripts
  INSTRUCTIONS.md               <- detailed setup and testing guide
  README.md                     <- this file

Technology

Concern	Choice
Map rendering	Leaflet.js (CDN, no build step)
Base tiles	OpenStreetMap (no API key)
Colour scale	chroma.js (CDN)
CSV parsing	PapaParse (CDN)
Neighbourhood boundaries	ONS Open Geography Portal (LSOA 2021)
Building footprints	Overpass API (OpenStreetMap, build-time only)
Point-in-polygon	shapely (Python, data generation only)
CSV data handling	In-memory only, never persisted
Hosting	GitHub Pages (static, free)
Build pipeline	None — plain HTML/CSS/JS

Privacy model

When a user uploads an HMO CSV in the browser:

• The CSV is parsed entirely in the browser (client-side JavaScript)
• Address matching uses data/oxford_buildings.geojson (static file, public OSM data)
• Postcode-to-LSOA lookup uses data/postcode_lsoa.csv (static file, public data)
• Zero external API calls are made at runtime
• CSV data is never cached or persisted — it lives in browser memory only and is discarded on page refresh
• No HMO data is ever sent to a server or stored in the Git repository

Data licence

LSOA boundaries are from the ONS Open Geography Portal and are available under the Open Government Licence.

Amenity point data is derived from OpenStreetMap and is available under the Open Database License (ODbL).