status of the project

We have come to know that Emaar MGF is about to initiate the process of calling Owners to get the Buyers Agreement signed. The agreement states that the delivery of the project is after 2 years from the start of construction. However, the agreement does not state in any way about the month of start of construction & does not intimate about the time of delivery of the project. This means that the project will be delivered after 2 years, starting from whenever they start the construction. It may be 5 yrs, 10 yrs & so on. I do not understand here what kind of agreement is this which does not state any construction start or delivery date?? This kind of agreement does not have any meaning or basically it is a useless agreement. What is your opinion on this? Should this kind of agreement be signed with Emaar?