Service tax query

IS BUILDERS AND DEVELOPERS LIABLE TO SERVICE TAX OR VAT? AND IF SHOP IS SOLD BEFORE GETTING THE OC FROM THE COMPETENT AUTHORITY WATH WOULD BE PAYABLE VAT OR SERVICE TAX PLEASE EXPLAIN WITH EXAMPLE INCLUDING AMOUNT.IS VAT OR SERVICE TAX LIBLE AFTER FULL COMPLITION OF CONSTRUCTION AND AFTER GETTING OC FROM COMPETENT AUTHORITY.IS THERE ANY ABATEMENT AVAILABLE OR CENVAT CREDIT AVAILABLE TO BUILDERS DEVELOPERS. PLZ ALSO GIVE THE TAX RATE.