The ODB - an experimental Open Database of Buildings

Metadata document: concepts, methodology and data quality

Version 2.0

Data Exploration and Integration Lab (DEIL)
Centre for Special Business Projects (CSBP)

Release date: March 1, 2019

Table of Contents

1. Overview

For the purpose of exploring open data for official statistics and to support geospatial research across various domains, work was undertaken to create an accessible and harmonized database of building footprints released as open data by various levels of government within CanadaFootnote 1. This document details the process of collecting, compiling, and standardizing the individual datasets of building footprints that were used to create the experimental Open Database of Buildings (ODB), which is made available under the Open Government License - Canada.

In its current version (version 2.0), the ODB contains approximately 4.4 million building footprints up from approximately 4.3 million footprints in version 1.0. This is due to the inclusion of four additional municipalities in version 2.0. The four additional municipalities, and their respective attributions, are provided at the end of the table in Appendix A. The database is expected to be updated periodically as new open datasets on buildings from government sources become available. This vector dataset is provided as a zipped shapefile at the provincial or territorial level.

Access to the dataset is available through the Statistics Canada website and can be found at Open Building Data: an exploratory initiative.

2. Data Sources

Multiple data sources were used to create the ODB. The data providers, which include municipal, regional, and provincial levels of government, are shown in Table 1. Attribution to each of these data sources is listed, as per the license requirements, in Appendix A. Where applicable, license versions are also shown. For further information on the individual licenses, users should consult directly with the information provided on the open data portals for the various data providers.

Table 1: Listing of data providers included in the current version of the Open Database of Buildings (ODB)

Alberta

  1. Airdrie
  2. Banff
  3. Canmore
  4. Chestermere
  5. Cochrane
  6. Edmonton
  7. Grande Prairie
  8. Lethbridge
  9. Strathcona County

British Columbia

  1. Chilliwack
  2. Courtenay
  3. Kamloops
  4. Kelowna
  5. Nanaimo
  6. New Westminster
  7. North Vancouver
  8. Prince George
  9. Saanich
  10. Squamish
  11. Surrey
  12. Vancouver
  13. Victoria
  14. Whistler
  15. White Rock

New Brunswick

  1. Fredericton
  2. Moncton
  3. Saint John

Northwest Territories

  1. Yellowknife

Nova Scotia

  1. Cape Breton
  2. Halifax
  3. Nova Scotia

Ontario

  1. Barrie
  2. Brampton
  3. Brantford
  4. Burlington
  5. Caledon
  6. Cambridge
  7. Durham Region
  8. Guelph
  9. Hamilton
  10. Huron County
  11. Kingston
  12. Kitchener
  13. Muskoka
  14. Newmarket
  15. Niagara Falls
  16. Niagara Region
  17. Norfolk County
  18. Oakville
  19. Ottawa
  20. St. Catharines
  21. Toronto
  22. Waterloo
  23. Waterloo Region
  24. Welland
  25. York Region

Quebec

  1. Longueuil
  2. Montreal
  3. Québec
  4. Repentigny
  5. Rimouski
  6. Rouyn-Noranda
  7. Shawinigan
  8. Sherbrooke

Saskatchewan

  1. Regina

3. Reference Period

Ideally, the reference period would be the period from which the underlying building data refers to. Such information, however, was usually not available from the open data portals. In lieu of this, Appendix A provides the date each municipal dataset used in the ODB was downloaded. Data were gathered between January 2018 and August 2018 from open data portals for version 1.0 of the ODB, and additional sources were downloaded in February 2019 for version 2.0. Users are cautioned that the download date should not be used to indicate the reference period of the data. If specific information concerning the reference period of data is required, users should contact the appropriate data providers shown in Appendix A.

4. Target Population

The goal of the ODB is to create a centralised and harmonized repository of building footprints available from government open data sources across Canada. Emphasis was placed on compiling buildings where substantial activity (e.g., economic activity) may occur. For this reason, footprints smaller than 10m2 were removed as they were deemed too small to be of interest for most users. As work on the experimental ODB progresses, definitions and thresholds will evolve. Users are reminded that unedited data can always be obtained directly from the open data portals of the various data providers.

5. Compilation Methodology

Individual building datasets were downloaded from their respective government open data portals. Within the 65 datasets obtained, each data provider attached a different set of variables to the building footprints. Only variables common across all data sources were included in the final output. Prior to merging, datasets were standardised and cleaned to ensure consistency in measurements and units. In the few cases where geographical coverage of municipal datasets intersected each other, a five meter buffer was applied to one dataset, and buildings within that buffer from the other datasets were removed.

6. Data Dictionary

This data dictionary below describes the variables contained within the exploratory ODB.

Variable - Object ID

Name
OBJECTID (alias FID)
Format
Object ID (specific to ArcGIS)
Source
Internally generated during data processing
Description
Unique object or field ID automatically generated during data processing

Variable - Shape

Name
Shape
Format
Geometry (specific to ArcGIS)
Source
Automatically generated from the geometric properties of the polygon datasets
Description
Describes the type of vector data in the dataset

Variable - Longitude

Name
Longitude
Format
Double
Source
Generated from the centroid of the building polygon
Description
The longitude in decimal degrees of the centroid of the building polygon

Variable - Latitude

Name
Latitude
Format
Double
Source
Generated from the centroid of the building polygon
Description
The latitude in decimal degrees of the centroid of the building polygon

Variable - Census subdivision unique identifier

Name
CSDUID
Data
Format Integer
Source
Canadian census subdivision boundaries 2016 (Statistics Canada GeoSuite product)
Description
The census subdivision ID where the building is located

Variable - Census subdivision name

Name
CSDNAME
Format
String
Source
Canadian census subdivision boundaries 2016 (Statistics Canada GeoSuite product)
Description
Name of census subdivision

Variable - Data Provider

Name
Data_prov
Format
Text (String)
Source
Created based on origins of input dataset
Description
Name of the municipality, region, or province/territory that provided the dataset

Variable - Building Unique ID

Name
Build_ID
Format
Text (String)
Source
Generated by concatenating the census subdivision unique identifier with a sequential 6-digit code that is unique to each building in that census subdivision
Description
A unique identification for each building based on the census subdivision in which it resides

Variable - Perimeter

Name
Shape_Length
Format
Float
Source
Calculated from the geometric attributes of the building polygon
Description
The perimeter of the building in units of metres (name specific to ArcGIS)

Variable - Area

Name
Shape_Area
Format
Float
Source
Calculated from the geometric attributes of the building polygon
Description
The area of the building in units of square metres (name specific to ArcGIS)

7. Record Layout

An example of the record layout in table format is reported below.

Example of the record layout in table format
OBJECTIDTable note 1 ShapeTable note 1 Longitude Latitude CSDUID CSDNAME Data_prov Build_ID Shape_Length Shape_Area
1 Polygon -115.561757 51.18907 4815035 Banff Banff 48150350000001 16.560241 16.963528
2 Polygon -115.569331 51.171372 4815035 Banff Banff 48150350000002 87.531972 330.625531
3 Polygon -115.569616 51.178173 4815035 Banff Banff 48150350000003 104.044015 573.938947
Table note 1

Field indexed automatically by the GIS software used during processing.

Return to table note 1 referrer

8. Data Accuracy

All building footprints in the ODB were collected from government sources of open data. In general, other than the processing required to harmonize the different sources into one database, the underlying datasets obtained from the various open data portals were taken "as-is". Users are advised that the individual methodologies used, as well as the amount of information describing these methodologies, varied by data provider. For more information on an individual data provider's methodologies, please follow the links to their website found in Appendix A.

During the processing stage to create the ODB, several steps were taken to improve accuracy and to standardize the output. A small number of building geometries that had improbable shapes were removed. Variables calculated by the data providers were recalculated based on the underlying geometries to ensure consistency in measurements and units (specifically, the measures for building area and perimeter, and in some cases, for latitude and longitude as well). Where geographical coverage of input datasets intersected each other, users are advised that the choice of buffer size applied (five metres was chosen) and which overlapped segments of buildings to be removed will impact the results. The choice of which segments to keep was based on several heuristic factors, specifically preference was given to datasets that appeared to have more detailed polygons and/or a higher number of building counts.

The experimental ODB represents the government open data that was found at the time of compilation and should thus not be interpreted as a complete or objective "ground-truth" of what buildings actually exist in Canada. The current coverage across Canada of the ODB is incomplete with data primarily existing for larger cities. The gaps in the database reflect areas where open data on buildings from government sources was not found.

9. Geographic Representation

The Open Database of Buildings is available on the Statistics Canada website in the following geographic representation:

  • Projection: Lambert conformal conic
  • False easting: 6200000.000000
  • False northing: 3000000.000000
  • Central meridian: -91.866667
  • Standard parallel 1: 49.000000
  • Standard parallel 2: 77.000000
  • Latitude of origin: 63.390675
  • Linear unit: metre (1.000000)
  • Datum: North American 1983 (NAD83)
  • Prime meridian: Greenwich
  • Angular unit: degree
  • Spheroid: GRS 1980

The North American Datum of 1983 (NAD83) is an adjustment of the 1927 datum (NAD27) that reflects the higher accuracy of geodetic surveying.

Appendix A: License Attributions

License Attributions
Municipality / Region / Province Province / Territory License Version (if provided) Link to Data License Date of Data Download Attribution Statement (in language of origin)
Banff Alta 2.0 About Banff Open Data 22/01/2018 Contains information licensed under the Open Government Licence – Banff.
Barrie Ont. 1.0 Open Government Licence – Barrie 24/01/2018 Contains information licensed under the Open Government Licence – Barrie.
Brampton Ont.   City of Brampton Open Data Terms of Use 22/01/2018 Copyright © 2012, The City of Brampton (All rights reserved.) All intellectual property and other rights in and to the Dataset belong to the City of Brampton.
Brantford Ont. 1.0 Open Government Licence – Brantford 22/01/2018 Contains information licensed under the Open Government Licence – Brantford.
Burlington Ont.   Terms of Use for Open Data Burlington 22/01/2018 Contains information provided by the City of Burlington under Terms of Use for Open Data Burlington.
Caledon (Region of Peel) Ont. 1.0 Open Data Licence for The Regional Municipality of Peel 24/01/2018 Contains public sector Information made available under The Regional Municipality of Peel's Open Data Licence - Version 1.0.
Cambridge Ont. 2.0 City of Cambridge - Open Data Licence Version 24/01/2018 Contains information licensed under the Open Government Licence City of Cambridge.
Canmore Alta   Town of Canmore Open Data Licence 22/01/2018 Contains information licensed under the Town of Canmore Open Data Licence.
Cape Breton N.S. 1.0 Open Data & Information Government Licence – PVSC & Participating Municipalities 07/02/2018 Contains information licensed under the Open Data & Information Government Licence PVSC & Participating Municipalities.
Chestermere Alta   Chestermere Building Footprints 22/01/2018 Contains information made available by the city of Chestermere.
Chilliwack B.C.   City of Chilliwack - Open Data - Terms of Use 22/01/2018 All right, title and interest (including all copyright, patent, and other intellectual property rights) remain vested in the City of Chilliwack at all times.
Cochrane Alta   City of Cochrane - Open Data Licence 22/01/2018 Contains information licensed under the Open Data Licence – Town of Cochrane.
Durham Region Ont. 1.0 Region of Durham - Open Data Licence 21/03/2018 Contains public sector Information made available under The Regional Municipality of Durham's Open Data Licence.
Edmonton Alta 2.1 City of Edmonton Open Data Terms of Use 22/01/2018 Contains information provided by the city of Edmonton under the City of Edmonton Open Data Terms of Use.
Fredericton N.-B.   New Brunswick - Open Data Policy 22/01/2018 Contains information made available by the city of Fredericton.
Grande Prairie Alta 1.0 City of Grande Prairie Open Data License 22/01/2018 Contains information licensed under the Open Data License – City of Grande Prairie.
Guelph Ont. 1.0 City of Guelph Open Government Licence 22/01/2018 Contains information provided by the City of Guelph under an open government license.
Halifax N.S. 1.0 Halifax - Open Data Licence 24/01/2018 Contains information licenced under the Open Government Licence – Halifax.
Hamilton Ont. 1.1 Hamilton - Open Data Licence Terms and Conditions 22/01/2018 Contains public sector Data made available under the City of Hamilton's Open Data Licence.
Huron County Ont. 1.0 https://www.arcgis.com/home/item.html?id=2b3c6868201545b1aa50f87ee2b4d937 20/03/2018 Contains information licensed under the Open Government Licence – The County of Huron.
Kamloops B.C. 1.0 Open Government Licence - Kamloops 18/07/2018 Contains information licensed under the Open Government Licence - Kamloops.
Kelowna B.C. 2 Open Government Licence - City of Kelowna 22/01/2018 Contains information licensed under the Open Government Licence City of Kelowna.
Kingston Ont. 1.0 City of Kingston Open Data Licence 22/01/2018 Contains information licensed under the Open Data Licence – City of Kingston.
Kitchener Ont. 1.0 Kitchener - Open data 24/01/2018 Contains information licensed under the Open Government Licence - The Corporation of the City of Kitchener.
Lethbridge Alta 1.0 City of Lethbridge - Open Data License 22/01/2018 Contains information licenced under the City of Lethbridge – Open Data License.
Longueuil Que. CC 4.0 Données Quebec - Licence Creative Commons 20/03/2018 Contient de l'information fournie par la ville de Longueuil et visée par CC BY.
Moncton N.-B.   Moncton - Terms of Use 24/01/2018 Contains information provided by the City of Moncton under the City of Moncton's Terms of Use.
Montréal Que. CC 4.0 Données Quebec - Licence Creative Commons (French only) 22/01/2018 Contient de l'information fournie par la ville de Montréal et visée par CC BY.
Muskoka Ont. 1.0 District Municipality of Muskoka – Open Data Licence 24/01/2018 Contains information provided by the District Municipality of Muskoka under licence.
Nanaimo B.C. 2.0 City of Nanaimo - Open Data Catalogue Licence 24/01/2018 Contains information licenced under the Open Government Licence – Nanaimo.
New Westminster B.C. 1.0 New West Open Data - Licence 24/01/2018 Contains information licenced under the Open Government Licence - City of New Westminster.
Newmarket Ont. 1.0 Town of Newmarket Open Data Licence 24/01/2018 Contains information licensed under the Open Data Licence - Town of Newmarket.
Niagara Falls Ont.   Niagara Falls - Open Data - Terms and Conditions 07/02/2018 Contains publicly available information provided by the City of Niagara Falls under the City of Niagara Falls Terms of Use.
Niagara Region Ont. 2 Open Government License 2.0 (Niagara Region) 20/07/2018 Contains information licensed under the Open Government Licence - Niagara Region.
Norfolk County Ont.   Norfolk County's Open Data Licence 20/03/2018 Contains public sector Information made available under Norfolk County's Open Data Licence.
North Vancouver B.C. 2.0 District of North Vancouver - Open Data - Buildings Metadata 24/01/2018 Contains information licensed under the Open Government Licence - North Vancouver.
Nova Scotia N.S. 1.0 Open Government Licence – Nova Scotia 24/01/2018 Contains information licensed under the Open Government Licence – Nova Scotia.
Oakville Ont.   Town of Oakville Open Data Licence 24/01/2018 Contains information licensed under the Open Government Licence – Town of Oakville.
Ottawa Ont. 2.0 Ottawa - Open Data Licence Version 24/01/2018 Contains information licensed under the Open Government Licence – City of Ottawa.
Prince George B.C. 2.0 Open Government License – City of Prince George 24/01/2018 Contains information licensed under the Open Government License – City of Prince George.
Québec Que. CC 4.0 Données Quebec - Licence Creative Commons (French only) 18/07/2018 Contient de l'information fournie par la ville de Québec et visée par CC BY.
Regina Sask.   Open Government Licence - City of Regina 24/01/2018 Contains information licenced under the Open Government Licence – City of Regina.
Repentigny Que. CC 4.0 Données Quebec - Licence Creative Commons (French only) 24/01/2018 Contient de l'information fournie par la ville de Repentigny et visée par CC BY.
Rimouski Que. CC 4.0 Données Quebec - Licence Creative Commons (French only) 18/07/2018 Contient de l'information fournie par la ville de Rimouski et visée par CC BY.
Saanich B.C.   Saanich Data Catalogue Licence 24/01/2018 Contains information licenced under the Open Government Licence - District of Saanich.
Saint John N.B. 01.0 Open Government Licence – City of Saint John 24/01/2018 Contains information licensed under the Open Government Licence – City of Saint John.
Shawinigan Que. CC 4.0 Données Quebec - Licence Creative Commons (French only) 20/03/2018 Contient de l'information fournie par la ville de Shawinigan et visée par CC BY.
Sherbrooke Que. CC 4.0 Données Quebec - Licence Creative Commons (French only) 14/03/2018 Contient de l'information fournie par la ville de Sherbrooke et visée par CC BY.
Squamish B.C. 2.0 District of Squamish - Open Data 24/01/2018 Contains information licensed under the Open Government Licence - Squamish.
St. Catharines Ont. CC 4.0 Creative Commons - Attribution 4.0 International 07/02/2018 Contains information provided by the city of St. Catharines licensed under CC BY.
Strathcona County Alta 1.0 Open Government Licence - Strathcona County 24/01/2018 Contains information licensed under the Open Government Licence – Strathcona County.
Surrey B.C. 2.0 Open Government Licence - Surrey 24/01/2018 Contains information licensed under the Open Government License – City of Surrey.
Toronto Ont. 1.0 City of Toronto - Open Data Licence 22/01/2018 Contains information licensed under the Open Government License – Toronto.
Vancouver B.C. 1.0 City of Vancouver - Open data catalogue 24/01/2018 Contains information licensed under the Open Government Licence – Vancouver.
Victoria B.C. 1 City of Victoria - Open Data Licence 24/01/2018 Contains information licensed under the Open Government Licence – City of Victoria.
Waterloo Ont.   City of Waterloo - Open Data User Licence 24/01/2018 Contains information provided by the City of Waterloo under licence.
Waterloo Region Ont. 2.0 Region of Waterloo - Open Data 24/01/2018 Contains information provided by the Regional Municipality of Waterloo under licence.
Welland Ont. 2.0 Open Government Licence – City of Welland 24/01/2018 Contains information licensed under the Open Government Licence – City of Welland.
White Rock B.C. 2.0 City of White Rock - Open Data 24/01/2018 Contains information licensed under the Open Government Licence – British Columbia.
Yellowknife N.W.T. 1.0 City of Yellowknife - Open Data License & Terms of Use 24/01/2018 Contains public sector Datasets made available under the City of Yellowknife's Open Data License v.1.
York Region Ont. 1.0 York Region - Building Footprints 24/01/2018 Contains public sector Information made available under The Regional Municipality of York's Open Data Licence.
Additions in version 2.0
Airdrie Alta 1.0 Open Data Licence - City of Airdrie 11/02/2019 Contains information licensed under the Open Data Licence – City of Airdrie
Courtenay B.C 2.0 Open Government Licence – City of Courtenay 11/02/2019 Contains information licensed under the Open Government Licence – City of Courtenay
Whistler B.C. 2.0 Resort Municipality of Whistler - Open Data Portal Terms of Use 11/02/2019 Contains information licensed under the Open Government Licence – Resort Municipality of Whistler.
Rouyn-Noranda Que. CC 4.0 Données Quebec - Licence Creative Commons (French only) 11/02/2019 Contient de l'information fournie par la ville de Rouyn-Noranda et visée par CC BY.
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