Understanding what has happened to a property over time can be extremely useful when investigating structural damage, drainage problems, retaining wall failures, previous alterations or unexplained building movement.
At Cornell Engineers, we regularly use public mapping, aerial photography, development records and service information to help understand how a site has changed.
No single source tells the whole story. The useful information usually comes from combining several sources and comparing what each one shows.
Why Property History Matters
A building may look quite different today from the way it looked when it was originally constructed.
Over time, owners may have:
- added extensions;
- removed walls;
- built retaining walls;
- changed ground levels;
- installed pools;
- added decks, sheds or carports;
- altered drainage;
- constructed new driveways;
- removed vegetation; or
- carried out work that was never well documented.
Historical information can help establish when those changes occurred and whether they may be relevant to a structural problem.
Before You Dig Australia
Before You Dig Australia is a useful starting point for locating underground services that may affect a property.
Depending on the location and service authority, information may be available about:
- water mains;
- sewer mains;
- telecommunications;
- electricity;
- gas; and
- other underground infrastructure.
Service information should be treated as indicative rather than a substitute for locating services on site. Exact alignment, depth and condition may require further investigation.
Brisbane City Council Development.i
For Brisbane properties, Brisbane City Council Development.i can be useful for researching development applications associated with a site.
Depending on the property and age of the development, records may help identify:
- development applications;
- extensions and alterations;
- planning approvals;
- changes in use; and
- documents associated with previous development work.
This can be particularly useful where the current building appears to differ from older drawings or where the timing of an alteration is important.
Queensland Globe
Queensland Globe is one of the most useful mapping resources available for Queensland property research.
It provides access to mapping layers, property information and aerial imagery across Queensland.
For engineering investigations, historical aerial imagery can be particularly useful.
Comparing imagery from different years may help identify when:
- an extension was constructed;
- a retaining wall appeared;
- vegetation was removed;
- a pool or outbuilding was added;
- ground levels changed;
- neighbouring development occurred; or
- drainage conditions around the property changed.
QImagery
Where older aerial photography is required, QImagery can provide access to historical Queensland aerial photographs.
This can be valuable where the history of a property extends further back than the imagery available through more recent mapping services.
Older aerial photographs can sometimes help establish whether a building, retaining wall, drainage feature or other structure existed at a particular point in time.
Google Street View
Google Street View can provide another useful historical record of a property.
Where historical Street View imagery is available, it may show changes to:
- building facades;
- retaining walls;
- driveways;
- fences;
- trees and vegetation;
- roofing;
- external additions; and
- neighbouring development.
For some investigations, even a small detail visible in an old street photograph can help establish when a change occurred.
Real Estate Listing Photographs
Previous property listings can also provide useful historical photographs.
Sites such as realestate.com.au may contain photographs from previous sales or rental campaigns.
These images can sometimes reveal:
- the previous condition of cracking or finishes;
- older retaining walls;
- former landscaping;
- previous building layouts;
- the timing of renovations; and
- structures that have since been altered or removed.
Listing photographs are marketing images rather than engineering records, so they need to be interpreted carefully. Wide-angle lenses, image processing and selective photography can distort scale and appearance.
Urban Utilities Mapping
For properties within the Urban Utilities service area, publicly available mapping may provide information about water and sewer infrastructure.
This can be important because underground services may affect:
- building extensions;
- footings;
- retaining walls;
- excavation;
- drainage investigations; and
- the interpretation of ground movement or water-related problems.
Where buried services are potentially relevant to a structural problem, mapping should be supplemented by appropriate site investigation.
Brisbane Stormwater Mapping
Brisbane City Council publishes spatial data that can assist with identifying stormwater infrastructure and other council assets.
This information can be particularly useful when investigating:
- overland flow;
- stormwater drainage;
- water collecting around buildings;
- retaining wall failures;
- erosion; and
- possible relationships between drainage infrastructure and building movement.
For more information about drainage investigations, see our drainage and stormwater inspection advice.
Queensland Geocoder
The Queensland Government’s address and geocoding tools can help relate street addresses to cadastral property information such as lot and plan details.
Lot and plan information is often useful when searching planning, survey and property records because it provides another way of identifying the land parcel.
Council Mapping Systems
Many Queensland councils provide their own mapping and development application systems.
Depending on the council, these systems may provide information about:
- property boundaries;
- contours;
- development applications;
- stormwater infrastructure;
- sewer infrastructure;
- planning overlays; and
- other council assets.
Examples include mapping and development systems operated by Brisbane City Council, Sunshine Coast Council, Gold Coast City Council and Mackay Regional Council.
These systems change from time to time, so if an old bookmark no longer works, start from the relevant council’s current planning or mapping page.
How We Use Historical Information in Engineering Investigations
Historical research is particularly valuable where the timing or cause of damage matters.
For example, we may compare historical information with current site observations when investigating:
- cracking and foundation movement;
- retaining wall failures;
- drainage changes;
- stormwater problems;
- insurance claims;
- building alterations;
- damage associated with neighbouring construction;
- flooding or erosion; and
- disputes about when damage occurred.
Aerial photographs, development records and old property photographs do not automatically prove causation, but they can provide valuable evidence about how a site has changed.
Do Not Rely on One Source
Public mapping and historical imagery are extremely useful, but they have limitations.
Dates may not be exact. Infrastructure locations may be approximate. Photographs may not show the area of interest clearly. Development records may be incomplete.
The most reliable conclusions usually come from comparing several independent sources with what can be observed on site.
Need Help Investigating a Property?
If you are dealing with structural damage, cracking, movement, drainage problems, a retaining wall failure or an insurance matter, historical property information may form part of a broader engineering investigation.
Send us the property address, photographs, relevant reports and a short description of what has happened.
We will review the information and let you know whether the matter is a good fit for Cornell Engineers before preparing a fee proposal.