Do we need to pay service tax on less carpet area < 650 sft

Dear Experts,

I bought a flat under construction in Bengaluru with Super Buit Up area(SBU) is 900 SFT.

Came to know that, buyer need not to pay any Service Tax , if the CARPET area is less than 650 SFT. 

In my case CARPET area is around 630 SFT (70% of 900),  do I need to pay Service Tax ?

Please clarify.

Thanks a lot in advance.

Mallikarjun