Importing San Jose building footprints into OSM

[3vivekb]

Basemap_2 at San Jose Public Works GIS resources seems to include building footprints. It should be evaluated for import into OSM.

[3vivekb]

Compare the https://github.com/osmlab/ms-building-import microsoft building footprints to the Public works footprints, do the comparison.

[1ec5]

If I’m not mistaken, that was Microsoft’s first tranche of buildings, drawn by humans. There’s also a second, newer tranche that’s more comprehensive but drawn algorithmically using computer vision, so it may be less accurate.

[1ec5]

This import is being tracked in greater detail in impiaaa/SV-OSM#3, as well as in this draft proposal.

[impiaaa]

Open questions:

• Figure out what to do with condos
• Decide on meters or feet
• Decide on "house" or "detached"
• Which sjc: tags are worth keeping and which should be omitted?
• What is the source data's vintage?

Preprocessing steps (to rewrite in SQL):

• Detect and split off buildings intersecting with existing OSM data
• Automatically group or remove large address sites (apartments, hotels, etc.)
• Small parcel, one address, one major building: Single home. Put address on building.
• Large parcel, one address, one major building: Possibly site (school, hospital, office). Deal with later.
• Small parcel, multiple addresses, one major building: Condo or duplex. Leave address points.
• Large parcel, multiple addresses, one major building: Office/apartments/hotel/other development. Delete, merge, or leave depending on clustering.
• Large parcel, one address, multiple buildings. Possibly site (school, hospital, office). Deal with later.
• Large parcel, multiple addresses, multiple buildings: Possibly settlement (mobile home park). Try to combine addresses with buildings. If common addtl_loc, use for parcel.
• Building intersecting multiple parcels: Condo or unit. Leave address point.

Translation steps:

• Expand street abbreviations/align with OSM
• Translate OSM tags

Manual steps:

• Join multi-part buildings
• Deal with sites
• Add missing streets

Process:

• Create import/dividing/conflation plan
• Create a wiki page
• Get community buy-in
• Add to Import/Catalogue
• Import review
• Create dedicated user account(s)

[1ec5]

Leave address point.

👍 We had mused about leaving address areas (ways tagged area=yes addr:*), but apparently openstreetmap-carto only imports address points, building areas, or landuse areas, not bare address areas.

[impiaaa]

Tasking manager project: https://tasks.openstreetmap.us/project/167

[impiaaa]

Updated link: https://tasks.openstreetmap.us/project/175

[1ec5]

@impiaaa finished the first phase of the import on July 4:

Before/after of one area in OSM Buildings

[1ec5]

We’ve kicked off phase 2 of the import to update geometries and add heights to all the preexisting, hand-mapped buildings in the city.

[1ec5]

@impiaaa has single-handedly completed phase 2, so now all that’s left is to help with validating the completed tasks.