An old-job claim arrives after the customer has changed the property

Today's condition may include years of change
A claim concerns work your business finished several years ago. The property may since have been altered, repaired or used differently. Preserve the original project records and identify later changes that are supported by evidence. Do not assume those changes caused the problem, but do not let the present condition be treated as an exact record of the site on completion without review.
Find the original baseline
Gather the agreed scope, relevant drawings, completion photographs and inspection records. Note their dates and limits. Avoid claiming that one final photograph proves every part of the work was satisfactory. Give the lawyer and appropriate expert the material needed to understand what was actually supplied and what the records can reliably show.
Keep historical records intact
Business.gov.au recommends protecting records and maintaining backups. Preserve the original files while investigating later events. If a former customer supplies new photographs, label their source and date rather than mixing them into the completion folder. A clear distinction between historical and current material helps advisers assess the chronology without first untangling a misleadingly combined file.
Source: business.gov.au: Record keeping
Consider a hypothetical alteration
Imagine a claim about water entering an area where another contractor later installed new fittings. The later work may be relevant, irrelevant or only part of the explanation. The original contractor should identify supported facts and seek competent assessment, not immediately blame the later trade. The example demonstrates a factual question rather than deciding causation or responsibility.
Seek access through appropriate channels
If an inspection is needed, arrange it with proper authority and legal or technical advice. Do not enter the property or alter disputed work without permission. Ask for relevant records of later works through the appropriate process. Keep requests focused and factual, avoiding accusations that documents were deliberately concealed merely because they are not yet available.
Maintain the formal response separately
Have the actual claim, court requirements and any limitation questions assessed promptly. Investigating later changes does not suspend response obligations or establish a defence by itself. Provide the adviser with the original baseline and the supported later chronology. The aim is an accurate account of how the property developed, rather than a comparison that assumes nothing changed between completion and the present complaint.