Sec 54 -payments to builder allowed?

In Sec 54 CapGain computations , can I take amounts payable to Builder. Builder seeks certainamts (not in stamp duty /or in regd deed )  for electricity ; for grounds, common banquet hall etc . Can IncTax challenge and delete these from my New House procurement costs (since no stamp duty payable on these possession-time-payable funds, payable to Builder compulsorily) ?