Nigeria Reinsurance Corporation - Abuja

My question goes like this: I have a clinic facility in a rented apartment which is not easily accessible to my client due to bad road leading to the building, and i wish to buy an uncompleted building close to the road and in the center of the community which asking price is N4.5m.
There is CO4.
Can the house document serve as collateral for me in your custody, till i complete payment in 24 or 36 months depending on your terms?