How to calculate number 13?

Dear all,

Construction is always a stucked up legal issue whether in direct or indirect tax.

I want some help. Under constuction of complex service, residential flats are taxable if more than 12. In my case, say for an example, "A" association is constructing a residential society in which there will be two towers - Tower "B" with 16 flats & "C" with 12 flats. Permission from land records i.e. survey numbers for both these towers are different but falling under the same premises and covered under the same entity i.e. "A" association.

For builder or contractor, these towers should be seen separately i.e. Tower B is taxable as flats are greater than 12 and C is not taxable as not greater than 12.

In my opinion, the same should be taxable as both are falling under the same premises and entity. For service tax, only one registration number is there and for service, even premises are no different so it is one complex only where total number of flats are 28 (16+12).

Please guide me if I am wrong. URGENT PLEASE.