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
- 2. Data sources
- 3. Reference period
- 4. Target population
- 5. Compilation methodology
- 6. Data dictionary
- 7. Record layout
- 8. Data accuracy
- 9. Geographic representation
- Appendix A: License attributions
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
- Airdrie
- Banff
- Canmore
- Chestermere
- Cochrane
- Edmonton
- Grande Prairie
- Lethbridge
- Strathcona County
British Columbia
- Chilliwack
- Courtenay
- Kamloops
- Kelowna
- Nanaimo
- New Westminster
- North Vancouver
- Prince George
- Saanich
- Squamish
- Surrey
- Vancouver
- Victoria
- Whistler
- White Rock
New Brunswick
- Fredericton
- Moncton
- Saint John
Northwest Territories
- Yellowknife
Nova Scotia
- Cape Breton
- Halifax
- Nova Scotia
Ontario
- Barrie
- Brampton
- Brantford
- Burlington
- Caledon
- Cambridge
- Durham Region
- Guelph
- Hamilton
- Huron County
- Kingston
- Kitchener
- Muskoka
- Newmarket
- Niagara Falls
- Niagara Region
- Norfolk County
- Oakville
- Ottawa
- St. Catharines
- Toronto
- Waterloo
- Waterloo Region
- Welland
- York Region
Quebec
- Longueuil
- Montreal
- Québec
- Repentigny
- Rimouski
- Rouyn-Noranda
- Shawinigan
- Sherbrooke
Saskatchewan
- 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.
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 |
|
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
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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