Vat on materials portion of civil works contract

we have an existing contractor for all our civil works. recently, we signed a contract regarding repairs. he is charging us VAT14.5% on total amount of contract, although his previous contracts has charged us VAT on materials only. Are there new rules in which the imposition of VAT has suddenly changed? is it alright if we dont pay VAT on total bill amount, and base it only on the materials portion? thank you.