Can tenant ask for more area of land then allotted afterwards

We tenents have executed notorized agreement in 2009 with a builder for constructing g+2 storey bld on ownership basis, with 20 sq feet extra area on reparing permission mode , that time builder was not having ownership, conveyance right and approved plan from bmc, we all have vacanted our house with faith , later on all our houses were demolished. From 2009 to 2015 , he has not started any work. Now he is having approved plan with G+7 storey bld, can we ask him to give more area ? Total area of plot is 250 sqmt with 21 tenents, Is govt rule of allotting area applicable