Building Footprints - ArcSDE version
1 IDENTIFICATION INFORMATION
1.1 Citation
Originator City of Portland
Publication date 1996
Title Building Footprints
1.2 Description
Abstract Regional building footprints. Original buildings are constructed of multiple "polygons" representing the different building heights. All polygons making up a single building have the same "building ID" [Bldg_ID], which was used to dissolve the buildings into generalized building footprints. Attributes that apply to the entire building were retained.
Purpose For mapping generalized building footprints, i.e., cartographic base maps.
Supplemental information Portland Central City, Lloyd District, Central Eastside, and OHSU all mapped by the Bureau of Planning and Sustainability. Buildings constructed after 2007 are derived from building permit information and aerial photos. All other buildings are derived from 2004 to 2007 LiDAR data.

All elevation and height data are in US Survey feet.
1.3 Time period of content Current
Last Dataset Update Date 2013-09-01 22:15:28.0
1.4 Status
Progress Complete
Maintenance/Update Frequency Unknown
1.5 Spatial domain
Description Clackamas County, Multnomah County, and Washington County, Oregon
West bounding coordinate -123.15156069
East bounding coordinate -122.31651100
North bounding coordinate 45.70263875
South bounding coordinate 45.23396470
1.6 Keywords
Theme keyword thesaurus
Theme keyword footprint, building, outline
Place keyword thesaurus
Place keyword Portland, Multnomah County, Washington County, Clackamas County, Oregon
1.7 Access Constraints None
1.8 Use Constraints These data are distributed under the terms of the City of Portland Data Distribution Policy. Care was taken in the creation of this data but it is provided "as is". The City of Portland cannot accept any responsibility for error, omissions, or positional accuracy.
1.10 Browse graphic
Browse graphic file name
Browse graphic file description
Browse graphic file type
1.13 Native data set environment File geodatabase
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2 DATA QUALITY INFORMATION
2.4 Horizontal positional accuracy Registered to tax lots.

Horizontal Accuracy:
Original building footprints have been modified to more accurately register with taxlots where appropriate. Overall horizontal accuracy is unknown. Buildings derived from LiDAR should have a horizontal accuracy of +/- 2'.

Vertical Accuracy:
Elevations and heights derived from photogrammetric data are within +/- 2' in most cases. Heights derived from LUR information or 3D models should be precise. Heights derived from LiDAR data are generally within +/- 15cm (~6") for buildings not obscured by vegetation, +/- .7m (~2.5') where buildings are covered by vegetation. Heights derived from field laser-range finder measurements are usually within +/- 7'.

Some building heights have been estimated using aerial photos or field visits. The accuracy of estimated elevations and heights are unknown.

Surface elevations derived from LiDAR data are generally within +/- 15cm (~6") for relatively flat areas not obscured by vegetation, +/- .7m (~2.5') where in areas of steep slopes or surfaces covered by vegetation. Surface elevations derived from the 2001 DEM are within +/- 5' in most cases.
2.5 Lineage
Process step
Process description For a complete description of the original building data and processing, refer to:

http://www.portlandonline.com/cgis/metadata/viewer/display.cfm?Meta_layer_id=52412&Db_type=sde&City_Only=False
                                 
Process date 1
Process step
Process description Building data is dissolved on the unique building ID (Bldg_ID) and a subset of other attributes that apply to the entire building to generate the dissolved building footprints.

                                 
Process date 2
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3 SPATIAL DATA ORGANIZATION INFORMATION
3.2 Direct spatial reference method
3.3 Point and vector object information
SDTS point and vector object type Polygon
Point and vector object count 620034
3.4 Raster object information
Raster object type NA
Row count 0
Column count 0
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4 SPATIAL REFERENCE INFORMATION
4.1 Horizontal Coordinate System
Grid coordinate system name State plane coordinate system 1983(91).
SPCS zone identifier 5076
Planar distance units International feet
Horizontal datum name North American Datum of 1983/1991 (HPGN)
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5 ENTITY AND ATTRIBUTE INFORMATION
5.2 Overview description Related data files and field descriptions follow:
Table Name Column Name Column Type Column Width Sample Domain Value Definition
building_footprints_pdx -- -- -- --
OBJECTID Numeric 8 -- A unique ID for each building polygon (generated by the GIS software); these IDs can change.
SOURCE String 30 -- The reference source used to map the building (same domain as the HGT_SOURCE attribute)
10' 2001 DEM A 10' resolution DEM generated from a 2001 DTM created from 2001 aerial photos. Surface elevations derived from the 2001 DEM are within +/- 5' in most cases.
3' LiDAR DEM Surface elevation derived from a 3' resolution LiDAR surface elevation model generated from 2004 through 2007 bare earth LiDAR point returns. Vertical accuracy is generally within +/- 15cm (~6") for relatively flat areas not obscured by vegetation, +/- .7m (~2.5') where in areas of steep slopes or surfaces covered by vegetation.
STATE_ID String 20 -- The state ID of the primary taxlot on which the building resides (usually derived from the center of the building polygon).
SURF_SRC String 30 -- The source information for the surface elevation
BLDG_ADDR String 50 -- The building's street address
BLDG_NAME String 50 -- The building name (if known)
ECOROOF String 1 -- "Y" indicates a building with a functioning ecoroof
NUM_STORY Integer 4 -- The maximum number of building stories (if known)
NUM_UNITS Integer 4 -- The number of residential units (if known)
BLDG_SQFT Integer 4 -- The building square footage (if known, usually gross)
YEAR_BUILT Integer 4 -- The year construction of the building was completed (if known)
BLDG_TYPE String 30 -- The type of building (house, garage, etc.). Not yet populated. Domain to-be-determined.
BLDG_ID String 30 -- The unique building ID. This is the master identifier for the building. These IDs do not change and will not be reused.
BLDG_USE String 30 -- Predominant building use. Not consistently populated outside Portland's Central City.
Commercial Office Commercial Office
Commercial Retail Commercial Retail
Industrial Industrial
Institutional Institutional
Parking Parking
Residential Residential
Vacant Vacant
LEED_RATE String 15 -- The "Leadership in Energy & Environmental Design" (LEED) rating of the building
ROOF_ELEV Numeric 8 -- The maximum roof elevation (above NAVD88 datum) of the building footprint in feet.
AVG_HEIGHT Numeric 8 -- The maximum height of the building footprint in feet.
HEIGHT_SRC String 30 -- The reference data source used to derive the height and elevation of the building or portion of a building.
3D Model Building height information derived from a digital 3D model provided by the developer (usually in SketchUp format).
Aerial Photos Building Height estimated from 6" aerial photos (flown every year)
Field Estimate Building height estimated in the field (by counting stories, for example).
Field Measurement Building height estimated in the field using a laser range-finder or other measurement method.
Inferred from Assessor Sqft Building height inferred from County Assessor square footage. Total assessed square footage is divided by the footprint square footage and the result multiplied by average floor height. Used for single-family buildings only.
Lidar DSM Building height manually derived from 2004 to 2007 LiDAR first-return "digital surface model" (DSM)
Lidar-Derived Building heights automatically derived from 2004 to 2007 LiDAR data by Watershed Sciences using the process described in the data lineage section above.
LUR/Building Permit Building height information derived from documents and plans submitted as part of the land-use review (LUR) and building permit process.
Oblique Aerials Building height information derived from oblique aerial photos and "street view" photos accessible in Bing, Google Earth, and Google Maps.
Other Building height information derived from a non-standard source (refer to notes)
Photogrammetrics Building height derived from photogrammetric data derived from aerial photos flown from 1987 to 1994.
HEIGHTCONF String 15 -- Overall confidence in the building height information
SURF_ELEV Numeric 8 -- The average surface elevation (above NAVD88 datum) of the land beneath the building footprint in feet.
CREATEDATE Date 36 -- The date that the building was originally mapped (added to the GIS data, if known)
MOD_DATE Date 36 -- The date of the most recent edits to the building footprint (if known)
MOD_NAME String 15 -- The initials of the person that last edited the building or portion of a building
FIELD_DATE Date 36 -- The date of any field visit to the building
REVIEW Date 30 -- "T" indicates the building or portion of the building needs to be reviewed for mapping and/or height accuracy.
NOTES String 150 -- Notes and comments related to the building or portion of a building
SUBAREA Date 30 --
LAT_CTR Numeric 8 -- Latitude of the center of the building footprint
LONG_CTR Numeric 8 -- Longitude of the center of the building footprint
USGS_QUAD Numeric 30 -- USGS Quad Location
WSUNIQUEID Numeric 30 -- Unique ID assigned by Watershed Sciences for buildings automatically derived from LiDAR (no longer used)
BPS_BLDGID Integer 4 -- Old BPS unique building ID (no longer used)
BLDG_NUMB Integer 2 -- The building number. Each building on a single parcel receives a unique number, starting with #1. These numbers are used to construct the unique building ID.
SQFT_SRC Integer 50 --
SQFT_CONF Integer 50 --
STORY_SRC Integer 50 --
STORY_CONF Integer 15 --
STRUC_TYPE Integer 30 --
STRUC_COND Integer 30 --
ROOF_TYPE Numeric 15 --
ORIENT Numeric 8 --
VOLUME Integer 4 --
MULTI_POLY Integer 1 --
MODIFIER Integer 30 --
CREATED_BY Date 30 --
SOURCE_REF Integer 50 --
MAX_HEIGHT Numeric 8 --
MIN_HEIGHT Numeric 8 --
SURF_OFF Numeric 8 --
SURF_ADJ Numeric 8 --
LENGTH Numeric 8 --
geodb_oid Integer 4 --
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6 DISTRIBUTION INFORMATION
6.1 Distributor
Contact organization City of Portland - BTS/CGIS
Address 1120 SW Fifth Avenue, Suite #450
City Portland
State or province OR
Postal code 97204
Contact voice telephone 503 823-5632
Contact facsimile telephone 503 823-9176
Contact electronic mail address CGIS@portlandoregon.gov
6.3 Distribution liability The information in this file was derived from digital databases on the City of Portland GIS. Care was taken in the creation of this file. The City  cannot accept any responsibility for errors, omissions, or positional accuracy.  There are no warranties, expressed or implied.
                                                       
6.4 Standard order process
Digital transfer information
Format name Shapefile - Cost Recovery fee will be charged for conversion.
Transfer size 300Mb
Digital transfer options:
Online option
Network resource name www.portlandonline.com
Access instructions The City of Portland can place the data on a CD upon request.  In most cases, a fee will be charged for data reproduction and preparation.  Call 503-823-5632 or e-mail cgis@ci.portland.or.us for instructions.
Offline option
Offline media CD-ROM
Recording format ISO9660 (DOS, Unix or Macintosh)
Fees
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7 METADATA REFERENCE INFORMATION
7.1 Metadata date 20130901
7.4 Metadata contact
Contact person Tammy Dong
Contact voice telephone 503 823-2249
Contact facsimile telephone 503 823-5194
Contact electronic mail address Tammy.Dong@portlandoregon.gov
7.5 Metadata standard name FGDC Content Standards for Digital Geospatial Metadata
7.6 Metadata standard version 19940608
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