Scenario: Crown Build is a medium scale developer in Australia who is currently the Principal (Client) of an on-going construction of a medium scale mix use development project in a prominent location in NSW. The traditional procurement approach is used to acquire the project. Having finalized the design development stages of the project, the Principal selected a suitable Contractor through competitive tendering. The project includes construction of four storey building. The project uses the 'AS4000 - 1997' as the form of construction contract. At the time of signing the contract, the contract sum was AUD 28 million and the contract period was 24 months. Contract included an advance payment. As per the contract, the contractor is paid monthly. Halfway through the construction of the superstructure of the building, the Contractor realises some structural deficiencies in the beam sizes. The Contractor informed the Superintendent of this unexpected situation in writing. Having consulted the Principal, the Superintendent issued new structural drawings with correct beam sizes. Furthermore, the Superintendent instructed to break the incorrect beam already constructed and replace them with new ones. The Contractor instructed its employees to proceed according to the instruction to break the beams and replace them with new once. In the meantime, due to variations issued by the Superintendent, the quantity of the stair handrails substantially increased. The Contractor is now preparing the tenth progress claim.

question)

Identify the legitimate time extension claims the contractor can make pursuant to the above scenario and explain the procedure to be followed. you can refer to the relevant AS4000-1997 clauses. 600 word