Group approach

we are looking into one campus with four buildings plus a food court; intend to register under CS; there is one virtual boundary for the whole campus; all four buildings are coming up together; single developer owned; food court is not intended to be registered (approx 12% of the other four blocks on built up area); one common STP system; two common chiller plants connected together for the four buildings; if we do under group approach, how do we handle the registration and certification fees? is it considered as one single project; can we register and certify by paying for one fee as for one building? can someone help please; thanks