#150 - Nova Scotia Building Import (Archived)

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Import building outlines from the Statistics Canada open building database. See the OSM Wiki for more details about the broader building outline import.

Created by LogicalViolinist - Updated - Priority: medium


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#Nova Scotia Building Import - https://wiki.openstreetmap.org/wiki/WikiProject_Canada/Canada_Stats_Canada_Building_Outlines_Import/Plan
When saving your work, please leave the default comment but add what you actually mapped, for example "added buildings and a residential road".

Before you being you will need the utilsplugin2 plugin installed in JOSM

  1. Select and open a task in JOSM. If it's too big (i.e. too much work or request is too big to load in JOSM) - go back and split the task into smaller ones. Load imagery layer. Esri World Imagery and sometimes Bing usually work best.

  2. Load buildings data for your square - click "Click to Download - Buildings" link under the Contribute Tab. Now let's work with the data and prepare it for merging into main OSM layer by tagging buildings with appropriate tags, removing overlapped outlines and fixing any other JOSM errors and warnings.

    1. Apply two filters: an inverse building=* filter to remove any non-building data( Windows -> Filter; On the filter window press add; Type building=*; Press submit filter; In the filter window click the checkbox in the I column). Another useful filter is type:node that removes all nodes leaving only building outlines to work with.

    2. Run validation for the entire import data layer. Typically you would see some errors and warnings. You can easily fix all or most errors automatically by clicking on Fix button.

    3. Once all errors are fixed run validation again. Fixing remaining warnings is usually straight-forward. Only exception is "Buidling inside building" warning. Some municipalities provide outlines for each building level so buildings outlines will appear to be overlapped. Leave building=yes tag for the main outline and change building tag to building:part=yes for those building parts that are inside the main outline. More information about using this tag.

    4. Once all warnings are fixed, classify buildings with appropriate OSM building tags based on imagery. Use lasso selection to select multiple buildings if needed. Here are the most common building tags you'll encounter:

      • building=detached - single detached home,
      • building=house - semidetached houses,
      • building=terrace - 3+ homes attached together,
      • building=apartment - multi-storey apartment buildings,
      • building=school - school,
      • building=garage - garage,
      • building=church - church,
      • building=industrial, building=commercial, building=retail when possible.
      • If not sure which tag to use - leave building=yes
  3. Before merging buildings data switch to OSM layer and see if there are any clusters of buildings without any meaningful tags you can delete to save time when merging. Just make sure you leave all buildings with useful tags, such as addresses, names, building types, etc.

  4. Now we are ready to merge buildings layer. Switch back to the data layer and do Edit->Merge Layer. You should have one layer with OSM data and only visible buildings. Select All (Ctrl-A) and run Validation. Now deal with all building-related warnings. Go one-by-one and conflate new outlines with existing buildings. Use Replace Geometry tool from utilsplugin2 plugin to preserve tags and history - select both new and existing outline and press Ctrl-Shift-G.

  5. Run Validation again and fix any remaining highway/building related warnings, such as crossing buildings/highways, etc.

  6. Upload changes to OSM with source = "Statistics Canada - Open Building Database"

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