D3 + Leaflet - map overlaid with voronoi grid for postcode area (Data: empty properties in Cardiff postcodes)

This example uses a combination of leaflet and D3 to display the number of empty properties in each postcode of Cardiff

Data is shown via a coloured voronoi grid. Each voronoi cell is centred on the geographic centroid of the postcode, as an approximation to the postcode area. This approximation is necessary because postcode boundary data are not readily available, despite the public having paid for them already. Cheers George.

Empty property data was accurate in 2014, but is now hopelessly out of date.