New York (state)/westchester county building import
(Westchester County Building Import) is an import of (Buildings) dataset which is of type (Shapefile) covering Westchester County in New York State. The import is currently (as of (2025-03-10)) at the planning stage.
Goals
- Add all missing buildings into the map from Westchester county
- Update and improve data where possible from the datasets provided
- Update and tag any missing public infrastructure such as libraries, fire stations, medical facilities, and police stations where missing.
- Add Addresses to building geometry or nodes where possible. Update if anything changes.
Schedule
Import will be done gradually over time. no set in stone schedule as of March 2025. Most of the project will be done manually using QGIS and JOSM, with TaskManager to potion the area into smaller more manageable chunks.
Import Data
Background
The data sets are all provided by the Westchester County Gis
Original Data Sets
- Buildings: The base buildings file can be found here. Also include the building height which can be added to the tags where missing. - Westchester Buildings
- Structures: This includes buildings and other structures. Can be used to add other details - Westchester Structures
- Fire Stations: This is a points list of all the locations of fire stations in the county. Includes name of the department, and contact information. Westchester Fire Stations
- Volunteer Ambulance Corps: This is a points list of the locations of all Ambulance Corps in the county. includes same information as FD - Westchester Ambulance Corps
- Libraries: A point list of all of the libraries in the county. Includes address, phone number, and website information for each branch. - Libraries
- Hospitals: This is all of the hospitals in Westchester County - Hospitals
- Municipal Buildings: This is a list of all of the town buildings - Municipal Buildings
- Police Stations: This is all of the police stations in the county - Police Stations
- Tax Parcel Data: This data set will provide the addresses for the building shapes where possible. Westchester County Tax Parcel Data
Links to the sources:
- Data source site: https://gis.westchestergov.com/
- Data license: https://website.tld/license
- Link to permission (if required): Explicit permission obtained via email on December 3rd, 2024. Quote below:
Email from Westchester County GIS Department from Courtney Wieber
Wieber, Courtney
Hello Andrew,
Thank you for your inquiry.
The statement/license on the wiki source page is still valid.
Our data is available on our website for free to use/download and we still ask to be given credit. Disclaimer is also the same/valid.
Our website: Westchester County GIS
Regards,
Courtney Wieber - GIS Specialist II148 Martine Ave, room 214
White Plains, NY 10601
Tel: (914) 995-7050
- OSM attribution (if required): https://wiki.openstreetmap.org/wiki/Contributors#United_States
- ODbL Compliance verified: yes
OSM Data Files
Original Source File: https://drive.google.com/file/d/1HQTBv2iQinEF9S29fQH-uf2EjmJTTyDt/view?usp=sharing
Modified File: 20240410 - Building-Address-Expanded.geojson
Import Type
This will be a one time import done in stages. I would be using JOSM to import the data into OSM. To make the import manageable i would be dividing the data into towns and villages.
Data Preparation
Data Reduction & Simplification
I will be using QGIS to go through the data and clean up and remove all of the unneeded information from the data sets. I would then use JOSM to load the data, and download the existing buildings, and check manually as well as with the validator for any duplicates or overlapping data.
Tagging Plans
Building Data
All buildings will receive the tag building=yes to match the existing building tag information. From the tax parcel data, we can also get what kind of structures or structure is on the lot. By cross referencing the tax code to the follow source NYS Property Tax Code Identification we can link each code to the property type, and from there find the closest match to an existing data type for buildings inside of OpenStreetMap
Address Data
The address data would come from the tax parcel dataset. Each tax parcel has the full address of the lot. Using QGIS and Join by location, we can add the address to the building geometry, and change the fields to match the existing OpenStreetMap data structure.
Changeset Tags
Fill in the values your changesets will use.
| Key | Value |
|---|---|
| comment | |
| import | yes |
| source | Westchester County GIS |
| source:url | https://gis.westchestergov.com/search?collection=Dataset |
| source:date | April 2023 |
| import:page | New York (state)/westchester county building import |
| source:license | license of source dataset, using this format. |
Data Transformation
The Buildings and Structures data has the following information. Below is an example.
| OBJECTID | 205894 |
|---|---|
| DESCRIPTION | BUILDING |
| FEA_CODE | 2,100 |
| PHOTO_DATE | March 31, 2000 |
| APPROX_ROOF_ELEVATION | 457 |
| BASE_ELEVATION | 434 |
| ACTUAL_HEIGHT | 23 |
| SHAPE | undefined |
| SHAPE.AREA | 1,155.449 |
| SHAPE.LEN | 139.902 |
Using QGIS, i would remove OBJECTID, DESCRIPTION, FEA_CODE, APPROX_ROOF_ELEVATION, BASE_ELEVATION, SHAPE, SHAPE.AREA, and SHAPE.LEN.
I would then keep the ACTUAL_HEIGHT and change to HEIGHT. Height is in feet and will be converted to meters. and PHOTO_DATE to source:date. I would add the BUILDING tag.
Update: 2025-04-11: After review, it was decided to remove the source:date tag
The end result should be something like this.
After Example
| Source:date | March 31, 2000 |
|---|---|
| Height | 23' |
| building | yes |
| comment | |
| import | yes |
| source | Westchester County GIS |
| source:url | [pending] |
| source:date | April 2023 |
| import:page | New York (state)/westchester county building import |
| source:license | Open Data |
Update: 2025-04-11: After community review, to make the tags smaller, the common information will be put into the change set comments. The tags source, source:license, import, and import:page would all be in the comments.
Data Transformation Results
This would be an example of the following Building and the data process
Initial Data
wkt_geom
|
Polygon Z ((-73.77862612855837199 41.08362440816004124 0, ...)) |
|---|---|
OBJECTID
|
171261 |
DESCRIPTION
|
BUILDING |
FEA_CODE
|
2100 |
PHOTO_DATE
|
2000-04-01T00:00:00.000Z |
APPROX_ROOF_ELEVATION
|
404 |
BASE_ELEVATION
|
393 |
ACTUAL_HEIGHT
|
11 |
SHAPEAREA
|
2014.685 |
SHAPELEN
|
195.4849 |
wkt_geom
|
MultiPolygon (((-73.77884633218762644 41.08365677882246558, ...))) |
|---|---|
MUNNAME
|
Mount Pleasant |
SWIS
|
553489 |
SBL
|
1.17E+19 |
PRINTKEY
|
117.11-4-36 |
PROPADDRESS
|
25 SHELLEY AVE |
PROPAPT
|
|
PROPERTYCLASS
|
210 |
CITYTOWN_NAME
|
Mount Pleasant |
CITYTOWN_SWIS
|
553400 |
OBJECTID_12
|
205449 |
SHAPEAREA
|
7501.715 |
SHAPELEN
|
350.0455 |
propertyClassLookUp_Description
|
One Family Year-Round Residence |
Modified Data
| Notes | ||
|---|---|---|
building
|
yes | |
height
|
11 | converted to meters. This seems to be calculated between actual elevation and building elevation. |
addr:housenumber
|
25 | |
addr:street
|
SHELLEY AVE | |
addr:city
|
Mount Pleasant | |
addr:postcode
|
10561 | |
source:geometry:ref
|
WestchesterGIS-BI-171261 | WestchersterGIS-BI(BuildingImport)-[OBJECTID] |
notes
|
single family year round home | this is the tax description of the property. Kept it in case of future reviews to better tag the building where possible. |
|
Removed - redundant | |
|
Removed - Data not useful. Latest update date of the source geometry provided by Westchester County | |
|
Relocated to Changeset Tags | |
|
Relocated to Changeset Tags | |
|
Relocated to Changeset Tags | |
source |
Relocated to Changeset Tags |
| Notes | ||
|---|---|---|
import
|
yes
|
moved from individual building to changeset |
source
|
Westchester GIS
|
moved from individual building to changeset |
source:license
|
Open Data
|
moved from individual building to changeset |
import:page
|
https://wiki.openstreetmap.org/wiki/New_York_(state)/westchester_county_building_import
|
moved from individual building to changeset |
2025-04-11 Updates
Addr:countrywas removed to clean tags upimportwas removed, and moved to the changeset commentssource:licensewas removed and moved to the changeset commentsimport:pagewas removed and moved to the changeset commentssourcewas removed, and moved to the changeset comments
Data Merge Workflow
Team Approach
initially ill be doing this solo. The account will be - Westchester_Building_Import
If anyone wants to volunteer and do this together, feel free to reach out!
Workflow
- Uploads will be done in small sections, either limited to the town limited for sections such as Mount Kisco, or Bedford. Otherwise, ill divide westchester into a grid to go section by section. There will be a task manager project set up to help track and divide up the county into manageable chunks.
Conflation
Manual (JOSM) with the plugin.
Building Conflation
If there is an existing building geometry during the upload process, the following will be done:
- compare the 2 outlines. if outlines are similar or same, delete the new outline and keep the old.
- If the outlines do not match, check aerial imagery and see which of the 2 outlines are closer to the existing images. merge any data and delete the building that does not match.
Address Conflation
We will be using the Seattle Import as a guide line for our address conflation. In short:
- If there is 1 address node per building, merge the address node into the building, and clean the data.
- If there is more than 1 address per building, See if the building has a primary address, and use that as the main geometry address. Keep all other address nodes untouched
- For vacant lots, or nodes with no geometry. Keep nodes as is and do not change.
Discussion
The post to the community forum was sent on 2025-04 and can be found here
Thread was made in slack in the import and import-proposal sections.