Assignment $2$: Case Study $(15$ marks$)$

Read the following case study:

"A construction project involves building a new office complex. The estimated cost is $$500,000.$ However, during the project, unexpected site conditions are encountered, resulting in additional costs of $$75,000.$ The client also requests changes to the original scope, adding $$30,000$ to the cost."

Calculate the revised estimated cost and explain the reasons for the changes. Discuss the importance of contingency planning and risk management in construction projects. $(15$ marks$)$