Correct the sentences regarding for modification work

Please help to simplify the sentences regarding options for modification work below. Thanks

To achieve the new cooling load demand, two commonly options were proposed to clients as follows.

1. Replacement of air handler unit with air duct and Enhancement of the cooling capacity of existing air conditioner
2. Requisition of extra air conditioning service from landlord for the center at non-office hours

The first option was not only over the budget, but there was technical difficulty in the installation of the new air conditioners, pipe and duct as no free space was reserved for the additional equipment and material in ceiling void. Achieving the option, modification and relocation of existing equipment should be required.

To avoid putting substantial investment on this floor and the lease of the floor depended on the business performance. Therefore, the client chose the second option to cater the business strategy and trim down the quantity of occupant, thereby cooperating the existing condition.