Service tax on flat booked before july 2010

Hi,

I have booked a 1 BHK flat in Jan 10, The Total cost of the flat including all expenses is 13 L.

Expected to get possesion in another 2 months.

My Builder is asking me 2.57% for Service tax.

As, I have booked it before July 2010 & cost of flat is less than 20 L.

(Cosidering, service tax is not applicable for Low cost housing projects ( cost is < 20 L))

I would like to know exact information on Service tax rules & applicability of service tax in above case.