Please Help: Service tax

Planing for construction of houses obtined in the F.Y 2010-11 for 100 houses. As on 01.07.2012(Reverse Charge Mechanisam starts)only 60 houses completed remaining 40 houses constructed after 01.07.2012. For Ex:amount paid to artchitect Rs.10.00 lakhs for 100 houses and completed 40 houses after 01.07.2012. Rs.1,03,000/- service tax paid. In this scenario is it possible to claim 40% of the Service tax as input.