Father's self property settlement deed advise

Hello Sir/Madam, My parents have 2,000 Sq. Feet of land in Coimbatore and we are 3 children of him (1st Daughter, 2nd Son, 3rd Son) and my father wants to write a settlement deed. He wants to divide the land of 2,000 Sq. Feet into 4 partitions of 500 Sq. Feet each to 3 of us and 1 partition to my parents them self. After their life time, their share of 500 sq. feet land should be divided among 3 of us equally. We are planning to construct 4 flats of each 700 square feet in that land, 3 for us and one for our parents. But for the 4th one, Can it be registered under all 4 of us as owners and how to settle this 4th one among 3 of us (my sister and brother) equally after my parents life time without any legal disputes. For the 4th one, my brother is not willing to invest, but wants to enjoy the share of the property, when it is sold after my parents life time. Parents also agreed to consider him as one of the owners, though no investment from him for this 4th flat. Please advise.