Building inspectors have the important task of checking that the property you are buying, selling or living in is safe and compliant to the building code. Identifying any defects of the building and providing a thorough report is central to that task in any building inspection. Major defects, if found, do mean trouble for the owner, but not all defects make a building unlivable or non-compliant with the Australian standard. Here is a guide to major and minor defects, and what makes an issue a ‘major defect’.

Definition of ‘major defect’

The definition of the term ‘major defect’ changed in 2015. Before that, major defects were known as ‘structural defects’, and had a narrower definition. Now, a defect is classified as major if it threatens the safety of the building’s occupants or is likely to cause a collapse.

Professional building inspectors use a two-step process to determine if a defect is major.

How building defects are categorised

Building defects can be classified as major or minor. Minor defects are different to major defects because they are repairable. Major ones are identified through a two-step process. So in a building inspection, what is considered a major structural defect?

Step 1: Determining if the defect is evident in a major element of the building

Major elements of buildings are any elements that stabilise and secure the entire structure, either internally or externally. These include the foundations, roof, beams and floors. A defect is major if it affects any of these. For example, a crack in the ceiling is minor, but if that crack goes deeper than the ceiling and into the beams that stabilise the house, it would constitute a major defect.

Damaged foundations are a major defect because they threaten the structural integrity of the entire building.

Waterproofing elements and fire safety systems are also included because they prevent potentially catastrophic water and fire damage.

Step 2: Identifying the root cause of the major defect

Once an inspector has determined if the defect affects a major building element, it’s time to find what caused it in the first place. 

The Home Building Act (1989) states that major defects can be caused by “defective design, defective or faulty workmanship, defective materials, or a failure to comply with the structural performance requirements of the National Construction Code (or any combination of these)”. If the issue is caused by any of these factors, it is likely to seriously endanger the safety of the occupants either in the short or long term – at worst, it could even cause the collapse or demolition of the entire building. So, ‘major defect’ is a suitable title!

Identifying minor defects in a building inspection

Minor defects are sometimes known as ‘maintenance defects’, because they are repairable. These issues don’t endanger the safety of the building’s occupants and are easily improved upon. Some common examples of minor defects in buildings are:

  • Paint weathering
  • Blemishes and dents
  • Corrosion of metal foundations and beams (e.g. due to rust)
  • Cracks in wall, ceiling or other
  • Uneven finishes


If you are concerned about a defect in your building and want to have an inspection done, we are here to help! Get in touch on our website or call us on 0432 261 380 to arrange your professional Building and Pest Inspection.