Joint development agreements

If Assessee has entered into Joint Development Agreement before levy of service tax (2008) and he transferred development rights to the builder. Now due to some issues construction stopped and continued after some time, got completed in 2015. Now the landowner got the constructed flats 4 out of 10 from the developer. Tell me Whether the service tax is applicable? if so, point of taxation and the value on which service tax to be payable and by whom? Assume there is no clause in the aggrement about payment of taxes, landlord is liable to pay anything for taxes?