2. Published Data

The data described below represents building outlines data openly available on the LINZ Data Service (LDS): https://data.linz.govt.nz/layer/101290-nz-building-outlines/

2.1. Data Model

To assist you in understanding these datasets, the structure and details of the data fields is described in tables below. The relationship between tables and directly related datasets is provided in a data model diagram

To enable changes between updates to be recorded and then queried using using LDS changesets, every table has a primary key. Primary keys in tables are shown by a field name with bold font.

2.2. Schema: buildings_lds

Description: Schema that holds tables published via the LINZ Data Service.

2.2.1. Table: nz_building_outlines

Description: NZ Building Outlines contains the most recent representation of each building as a building outline.

Column Name

Data Type

Length

Precision

Scale

Allows Nulls

Description

building_id

integer

32

No

Unique identifier for a building. The building id is persistant for the same building across all of the building outlines that represent it.

name

varchar

250

No

The name of the building where known. If no known name this will be an empty string.

use

varchar

40

No

The building use maintained for the Topo50 map series. If no known use this will default to Unknown.

suburb_locality

varchar

80

No

The suburb / locality that the majority of the building outline is within. Sourced from NZ Localities (an NZ Fire Service owned dataset).

town_city

varchar

80

No

The town / city that the majority of the building outline is within. Sourced from NZ Localities (an NZ Fire Service owned dataset).

territorial_authority

varchar

100

No

The territorial authority that the majority of the building outline is within. Sourced from Stats NZ.

capture_method

varchar

40

No

The method by which the geometry was captured e.g. Feature Extraction.

capture_source_group

varchar

80

No

The source from which the geometry was captured e.g. NZ Aerial Imagery.

capture_source_id

integer

32

No

The id of the capture source area - currently all ids are a foreign key to the NZ Imagery Surveys dataset.

capture_source_name

varchar

100

No

The title/name of the specific capture source area.

capture_source_from

date

No

The earliest date on which aerial photographs were taken as part of the related imagery survey.

capture_source_to

date

No

The latest date on which aerial photographs were taken as part of the related imagery survey.

last_modified

date

Yes

The most recent date on which any attribute or geometry that is part of the building outline was modified.

shape

geometry

Yes

The geometry of the building outline represented as a Polygon using NZTM2000 / EPSG 2193. Internal rings are possible multiple external rings are not.

2.2.2. Table: nz_building_outlines_all_sources

Description: NZ Building Outlines: All Sources contains all combinations of outline / building / name / use that have existed within the building outlines system, and the dates for which that combination existed.

Column Name

Data Type

Length

Precision

Scale

Allows Nulls

Description

building_outline_id

integer

32

No

Unique identifier for the building outline. The building outline id is unique to one representation of a building.

building_id

integer

32

No

Unique identifier for a building. The building id is persistant for the same building across all of the building outlines that represent it.

name

varchar

250

No

The name of the building where known.

use

varchar

40

No

The building use maintained for the Topo50 map series.

suburb_locality

varchar

80

No

The suburb / locality that the majority of the building outline is within. Sourced from NZ Localities (an NZ Fire Service owned dataset).

town_city

varchar

80

No

The town / city that the majority of the building outline is within. Sourced from NZ Localities (an NZ Fire Service owned dataset).

territorial_authority

varchar

100

No

The territorial authority that the majority of the building outline is within. Sourced from Stats NZ.

capture_method

varchar

40

No

The method by which the geometry was captured e.g. Feature Extraction.

capture_source_group

varchar

80

No

The source from which the geometry was captured e.g. NZ Aerial Imagery.

capture_source_id

integer

32

No

The id of the capture source area - currently all ids are a foreign key to the NZ Imagery Surveys dataset.

capture_source_name

varchar

100

No

capture_source_from

date

No

capture_source_to

date

No

building_outline_lifecycle

varchar

40

No

The lifecycle of the building outline. Lifecycles with an end_lifespan date may either be “Removed” (new aerial imagery shows no evidence of the building) “Replaced” (a new building outline exists captured from new aerial imagery) or “Recombined” (new building outlines exist captured from new aerial imagery but in an m:n relationship). Lifecycle relates to the status of the building outline only. See nz_building_outlines_lifecycle to determine recombined building relationships.

begin_lifespan

date

No

The date the building outline was added to NZ Building Outlines database.

end_lifespan

date

Yes

The date the building outline was removed replaced or recombined within the NZ Building Outlines database.

last_modified

date

No

shape

geometry

Yes

The geometry of the building outline represented as a polygon using NZTM2000 / EPSG 2193. Internal rings are possible multiple external rings are not.

2.2.3. Table: nz_building_outlines_lifecycle

Description: The lifecycle table stores the relationship between buildings when one building is split into two buildings or two buildings are merged into one building. This will generally occur when a building outline was erroneously captured encompassing two buildings, which later becomes clear with additional aerial imagery.

Column Name

Data Type

Length

Precision

Scale

Allows Nulls

Description

lifecycle_id

integer

32

No

Unique identifier for a lifecycle.

parent_building_id

integer

32

No

Foreign key to the buildings_lds.nz_building_outlines_all_sources table. All records stored as parent buildings will have a date in building_end_lifespan.

building_id

integer

32

No

Foreign key to the buildings_lds.nz_building_outlines_all_sources table. This is the child in the relationship - (one of) the building(s) that replaced the parent building.