Unbuilt residential floor area by city block in one postal code area

The city blocks of the Helsinki capital region (Helsinki, Espoo, Vantaa, Kauniainen) that still have unbuilt residential floor area in valid detailed plans, from HSY's SeutuRAMAVA by block (via Helsinki Region Infoshare, CC BY 4.0). Floor areas are m² of building rights (k-m²): residential is the apartment-block plus the small-house reserve. Each block is placed whole, unclipped, in the postal area that holds its interior point (a block on land reclaimed beyond the areas' shoreline goes to the nearest capital-region area within 500 m), so an area's blocks need not add up exactly to its hri_reserve_residential figure.

registerDate is the block release's plan-register date and postalRegisterDate that of the per-postal-code figures; aligned is true when they are the same release, and only then do the blocks explain the figure beside them. registerDate is null when no block release is loaded. An area outside the capital region returns an empty blocks array; an unknown code 404. Cached for an hour.

Example request: https://suomiatlas.com/api/v1/postal-codes/00700/reserve-blocks