Buildings

Disclaimer

Geoscape Australia believes this publication to be correct at the time of printing and does not accept responsibility for any consequences arising from the use of the information herein. Readers should rely on their own skill and judgement to apply information to particular issues.

This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission of Geoscape Australia.

Overview

Buildings is a digital dataset representing buildings across Australia. The Buildings dataset has relationships with the G-NAF, Cadastre, Property and Administrative Boundaries products produced by Geoscape Australia.

Data quality and potential capture timelines will vary across Australia based on three categories. Each category has been developed based on several factors defined by the population distribution (categorised based on population size), industrial/commercial activities, the probability of natural events (e.g. flooding) and the image source.

• Urban (satellite source) - areas with a population greater than 200, or with significant industrial/commercial activity in a visual assessment, digitised from satellite imagery

• Urban (aerial source) - areas with a population greater than 200, or with significant industrial/commercial activity in a visual assessment, digitised from aerial imagery

• Rural – all other areas

Geoscape welcomes your feedback on the Buildings product. We also publish regular product development updates on our website ( www.geoscape.com.au ).

Release Summary

This product was released to customers on 16 December 2024 with data extracted on 10 December 2024.

• This release is a full national data population for Version 3.3 of the Buildings product, described by the Buildings Product Guide v3.3.

Any issues that have been identified for this release are described in the Issues section.

This release includes updates for the areas listed in the table below.

Locations of updated areas by State

State	Location	Urban Area (km2)
NSW	Blacktown City Council	132
NSW	Blue Mountains City Council	14
NSW	Camden Council	9
NSW	Cumberland Council	8
NSW	Fairfield City Council	82
NSW	Griffith City Council	28
NSW	Liverpool City Council	194
NSW	Parkes Shire Council	39
NSW	Penrith City Council	247
NSW	Wollondilly Shire Council	23
QLD	Brisbane City	639
QLD	Gold Coast City	437
QLD	Logan City	503
QLD	Moreton Bay City	366
QLD	Noosa Shire	186
QLD	Redland City	181
QLD	Scenic Rim Regional	79
QLD	Sunshine Coast Regional	194
SA	Alexandrina Council	123
SA	City of Victor Harbor	73
VIC	Greater Bendigo City	183
Total		3740

[1]

Location names are derived from an intersection with the most recent Local Government Area dataset, Geoscape, 2023.

Spatial files of the updated areas are available upon request via support@geoscape.com.au.

Change Notifications

NSW building_property record count increases

For the September 2024 Property release, Geoscape introduced approximately 1,160,000 additional NSW property records that relate to Strata cadastre parcels. These properties provide additional property information at sites where only the property relating to the Lot parcel was previously provided. This increase in property records has resulted in a record count increase in the NSW building_property table by approximately 6.2 million records.

Urban Fringe Refresh

Geoscape has started to expand the refresh areas of buildings where aerial imagery is available as a single source. This will extend mostly into the fringes of significant urban areas. Buildings in these areas will have improved geometries as well as roof material, shape, colour and type attributes. Any refresh activity will update the building_review_date attribute. Geoscape is using advanced comparison algorithms to identify whether the refreshed capture represents the same building as the previous capture and on that basis, if no refreshed height attributes are available, the existing heights will be maintained.

Issues

New Issues

No new issues to note.

Resolved Issues

No new resolved issues.

Known Issues

Incorrect metal primary_roof_material assignment

In the update areas for the September 2024 release we noticed that a large number of buildings have been classified with a primary_roof_material of ‘Metal’. On investigation, it was identified that this classification was not correct in many cases and so the primary_roof_material values were rolled back to the previous (June 2024) values where possible. We are looking to update these areas in an upcoming release to resolve remaining mis-classification and are working with our data supplier to improve this classification for future supplies.

Incorrect roof_type, roof_shape and roof_slope assignment

In the update areas for the September 2024 release we noticed that a large number of buildings have been classified with a roof_type and roof shape of ‘Flat’ and roof_slope of ‘0’. On investigation, it was identified that this classification was not correct in many cases and so these values were rolled back to the previous (June 2024) values where possible. We are looking to update these areas in an upcoming release to resolve remaining mis-classification and are working with our data supplier to improve this classification for future supplies.

Centroid not within building polygon

When mapping the building centroid from the centroid_longitude and centroid_latitude there will be occurrences where the point does not fall inside the building geometry. This occurs because of the complexity of the building geometry and impacts < 0.1% of buildings. A fix for this issue will be investigated for a future release.

Swimming_pool_adjacent incorrectly ‘null’

Some records containing attribution for swimming_pool_review_date also contain ‘null’ attribution for swimming pool adjacent where the allowed values are ‘no’ or ‘yes’. This affects < 0.25% of buildings.

Duplication of buildings between update areas

New and updated buildings are captured within Areas of Interest (AOIs). Buildings that intersect two adjacent AOIs are duplicated. This issue affects approximately 1,800 buildings.

Duplicate building polygons

There are 8,417 buildings with duplicate geometries, resulting in 8,427 additional building polygons present. A fix for this issue will be investigated for a future release.

Roof colour assignment

There is an over classification of light roof colours primarily in the Melbourne region. Advances in processing has improved this issue in recent releases.

Building position offset from imagery

There is evidence of buildings having a horizontal shift of approximately 0.5m in the NSW suburbs of Parramatta and the Dee Why area. This has occurred where the new shift to the digital elevation model has not worked as intended. As we continue to refine the aerial derived building processes, we’ll seek to resolve this issue.

Over-capture of metal roof material in aerial supplies

In the June 2022 release, we have noticed that there is an over-capture of Metal roof type in the aerial capture. This occurred primarily for residential buildings. In some areas of the new aerial capture (e.g. Perth and Cairns), Metal classification was actually improved overall in relation to the previous satellite capture (satellite previously incorrectly classified Metal roofs as Tile). We are working with our production partners to improve the accuracy of the roof_material attribute, which can be affected by image smoothing, causing Tile roofs to be incorrectly classified as Metal.

Future Considerations

This section outlines enhancements or changes under consideration, but not planned into a specific release. For further details on future initiatives, please contact Geoscape Support.

Legacy ‘CAD’ naming

The building_cad table contains a field that is called ‘cad_pid’, while the Cadastre product has an attribute called ‘cadastre_pid’. We have input the ‘cadastre_pid’ values into this ‘cad_pid’ field to not affect customer processes with attribute name changes. In addition the table name of ‘building_cad’ no longer matches the Cadastre product. There is no current plan to change either the ‘building_cad’ table name or ‘cad_pid’ field name.

Additional Total Floor Area attribute

Geoscape intends to introduce a new total_floor_area attribute to a future release of the Geoscape Buildings product. This attribute will provide the estimated sum of floor space across all levels of a building. At the time of the addition of this new attribute there will be a minor increment to the Geoscape Buildings product version.

Annex A – Release Counts

For the buildings table the additional, retired, updated and total building counts, as well as the percent change to the previous release have been listed in the table below. For the aspatial tables the total record counts have been listed.

TABLE	STATISTIC	FLAG	ACT	NSW	NT	OT	QLD	SA	TAS	VIC	WA	TOTAL
buildings	Additional		0	35,644	0	0	76,275	1,571	0	19,437	0	132,927
	Retired		0	25,539	0	0	65,966	745	0	20,931	0	113,181
	Updated		488	427,608	359	0	682,349	6,070	2,679	96,194	5,797	1,221,544
	Total		251,664	5,281,885	160,205	449	3,790,814	1,780,065	594,333	4,990,913	2,265,140	19,115,468
	% Change		0.00%	0.19%	0.00%	0.00%	0.27%	0.05%	0.00%	-0.03%	0.00%	0.1%
	Solar Panel	Yes	50,705	646,049	15,835	8	713,470	294,658	32,227	567,915	387,921	2,708,788
		No	199,639	3,697,267	111,233	329	2,469,698	1,130,881	403,908	3,612,377	1,459,230	13,084,562
	Swimming Pool Adjacent	Yes	18,587	698,640	38,975	0	774,322	129,070	9,062	299,023	349,790	2,317,469
		No	231,811	3,657,326	87,564	355	2,417,813	1,295,091	430,050	3,896,708	1,501,789	13,518,507
building_cad			299,350	12,200,226	323,577	554	5,720,816	2,279,304	719,895	9,575,731	4,516,541	35,635,994
building_property			260,672	12,504,287	263,381	0	5,706,586	2,195,232	625,395	11,780,694	2,280,943	35,617,190
building_address			905,334	11,700,407	301,589	151	9,599,628	2,928,129	732,808	8,722,032	3,990,638	38,880,716

References

[Aerometrex, 2023]

Aerometrex. Aerial imagery. Raster Dataset, 2023. URL: https://aerometrex.com.au/.

[Geoscape, 2023]

Geoscape. Local government areas 2.0. 2023. URL: https://docs.geoscape.com.au/projects/lga_guide/en/stable/index.html.