A dilapidation report is usually requested by civil or infrastructure contractors when a major construction (roads, rail etc) is about to commence. Especially when the construction is within close proximity of the residential/ commercial areas where there may be resultant damage to existing property due to the construction.
These inspection surveys are done prior to any work or construction commencing. This is done to ensure that any claims made against the contractor in the future are legitimate. The report will be used as point of reference if a claim is made that the construction work carried out by the contractor was the cause of the damage or if the damage was pre-existing.