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 27 March 2024 with data extracted on 20 March 2024.

  • This release is a full national data population for Version 3.2 of the Buildings product, described by the Buildings Product Guide v3.2.

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

Cowra Shire Council

31

NSW

Eurobodalla Shire Council

45

NSW

Kempsey Shire Council

132

NSW

Mid-Coast Council

19

NSW

Port Stephens Council

59

NSW

Wingecarribee Shire Council

58

QLD

Livingstone Shire

4

QLD

Rockhampton Regional

71

SA

The Rural City of Murray Bridge

51

VIC

Banyule City

62

VIC

Boroondara City

36

VIC

Brimbank City

64

VIC

Cardinia Shire

77

VIC

Casey City

284

VIC

Darebin City

42

VIC

Frankston City

84

VIC

Glen Eira City

11

VIC

Greater Dandenong City

135

VIC

Hume City

295

VIC

Kingston City

87

VIC

Knox City

108

VIC

Macedon Ranges Shire

27

VIC

Manningham City

127

VIC

Maroondah City

61

VIC

Melton City

213

VIC

Merri-Bek City

41

VIC

Mitchell Shire

49

VIC

Monash City

81

VIC

Moonee Valley City

26

VIC

Moorabool Shire

39

VIC

Nillumbik Shire

106

VIC

Stonnington City

5

VIC

Surf Coast Shire

24

VIC

Whitehorse City

64

VIC

Whittlesea City

181

VIC

Wyndham City

142

VIC

Yarra Ranges Shire

241

WA

City of Armadale

154

WA

City of Bayswater

35

WA

City of Belmont

40

WA

City of Bunbury

54

WA

City of Canning

65

WA

City of Cockburn

131

WA

City of Fremantle

20

WA

City of Gosnells

108

WA

City of Joondalup

94

WA

City of Kalamunda

117

WA

City of Kwinana

113

WA

City of Mandurah

94

WA

City of Melville

53

WA

City of Nedlands

18

WA

City of Perth

16

WA

City of Rockingham

171

WA

City of South Perth

20

WA

City of Stirling

108

WA

City of Subiaco

6

WA

City of Swan

230

WA

City of Vincent

11

WA

City of Wanneroo

239

WA

Shire of Capel

16

WA

Shire of Dardanup

21

WA

Shire of Harvey

33

WA

Shire of Mundaring

90

WA

Shire of Murray

36

WA

Shire of Peppermint Grove

1

WA

Shire of Serpentine-Jarrahdale

113

WA

Town of Bassendean

10

WA

Town of Cambridge

20

WA

Town of Claremont

5

WA

Town of Cottesloe

4

WA

Town of East Fremantle

4

WA

Town of Mosman Park

4

WA

Town of Victoria Park

18

Total

5,454

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

Change Notifications

ESRI Shapefile width increase - Cancelled

In the previous release report, we mentioned that the width of numeric fields within Esri Shapefiles would increase by one for this current release. A recent bug fix in our packaging application has been applied to make this change not necessary.

Improvements to address attribute in building_address table

Geoscape have expanded unit type values from short form to long form for the address attribute within the building_address table for the March 2024 release. We have applied this change to improve the clarity of the address label and better align it with our other addressing products. An example of this change is shown below:

December 2023 short-form unit type:

EUREKA MARDROSS GARDENS ALBURY TNHS 31 33 MARDROSS CT, NORTH ALBURY NSW 2640

March 2024 long-form unit type:

EUREKA MARDROSS GARDENS ALBURY TOWNHOUSE 31 33 MARDROSS CT, NORTH ALBURY NSW 2640

This change will not affect address_pid values within this table.

Removal of the ‘Documents’ folder from data packages

From November 2023, Geoscape will be progressively moving product descriptions, guides and reports online to https://docs.geoscape.com.au

Commencing with the May 2024 release, data packages will no longer include the Documents folder.

Issues

New Issues

No new issues to note.

Resolved Issues

Building Height Errors

Geoscape has identified approximately 100,000 building records where height attribution (building_height and eave_height) had previously contained errors causing larger heights than the real-world buildings. Errors in building heights impacted the quality of derived attribution including building volume and estimated levels.

These issues occurred due to artefacts in the Digital Surface Models (DSM) impacting algorithms that calculate building heights. This issue caused height values outside of our quality thresholds to be assigned in the areas of: Melbourne, Brisbane (City LGA), Perth, Orange, Cairns, Townsville, Coffs Harbour, Canberra, Bendigo, Geelong, Albury-Wodonga, Grafton, Dubbo, Bundaberg and Tamworth.

The majority of affected buildings had heights with errors in the range of 5-10m. However, occurrences of much more significant localised impact was observed of up to ~70m.

Geoscape has either recaptured the areas or applied corrections to these heights for the March 2024 Buildings release in order to assign values that more closely align with real-world heights. This, in turn, has resulted in more accurate volume and estimated_levels calculations for these features. The camera systems causing the DSM quality issue won’t be used for further Buildings updates.

Shapefile CNTRD_LONG and CNTRD_LAT Number Width Increase

We have become aware that for the ESRI Shapefile format, the CNTRD_LONG and CNTRD_LAT fields within the buildings table had been set with incorrect field width/precision of number (9,6). Although this width matches the product data model, Shapefiles include the decimal place towards the width which means that this value should have been assigned as number (10,6) to support possible values. This caused the last digit of the longitude and latitude to be set as 0 due to the value exceeding the file width/precision. For example, a longitude value of ‘143.546624’ would be set as ‘143.546620’ in the Shapefile output. This means that Shapefile building centroid longitude and latitude values previously had error of up to 0.12m depending on how far away the real last digit was from zero. This issue has been resolved in the March 2024 release by increasing the width/precision to number (10,6) within Shapefiles.

Known Issues

roof_material classification

Over classification of buildings with a primary roof material of ‘Tile’. Geoscape Australia continues to work with its partners to improve the techniques used in the classification of roof materials. For further information please refer to Classification Correctness - Building Roof/Roof Material in the product description.

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

ACT

NSW

NT

OT

QLD

SA

TAS

VIC

WA

TOTAL

buildings

Additional

31

48,803

0

0

19,722

9,604

0

475,187

128,314

681,661

Retired

113

17,196

0

0

6,653

4,905

0

363,748

46,000

438,615

Updated

10,339

186,060

115

0

115,595

20,016

10,444

1,620,625

1,328,490

3,291,684

Total

242,136

5,216,664

160,205

449

3,734,954

1,711,331

594,333

4,947,000

2,262,526

18,869,598

% Change

-0.03%

0.61%

0.00%

0.00%

0.35%

0.28%

0.00%

2.3%

3.78%

1.3%

Solar Panel

Yes

37,964

593,590

15,835

8

653,295

244,746

32,227

546,769

386,964

2,511,398

No

202,607

3,684,153

111,233

329

2,472,525

1,110,205

403,908

3,587,867

1,457,573

13,030,400

Swimming Pool Adjacent

Yes

17,881

667,495

38,978

0

751,097

109,077

9,062

297,007

348,614

2,239,211

No

222,792

3,622,998

87,561

355

2,383,993

1,244,455

430,050

3,853,436

1,500,351

13,345,991

building_cad

287,890

11,805,385

322,880

554

5,598,286

2,206,001

719,891

9,513,334

4,502,363

34,956,584

building_property

251,161

6,234,664

262,735

0

5,592,492

2,134,978

625,873

11,644,907

2,277,984

29,024,794

building_address

695,424

9,994,700

239,646

75

5,708,810

2,166,208

667,829

7,881,268

3,586,769

30,940,729

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.