Estimated costs for the Waitaki District Council's cultural facility development project have increased by 33%.

However project chairman Councillor Hugh Perkins says the increase will not affect ratepayers.

The now $6 million amalgamation of the Forrester Gallery, North Otago Museum and Waitaki District Archive will require the council to up its ante. Perkins says the extra funds will come from depreciation reserves set aside for the Forrester Gallery.