Rawlinsons Cost Guide is used for Australian estimates. You might be able to find the equivalent for your country by searching for this one as a starting point
BNI Building News (bnibooks.com) publishes "costbooks" for general construction, electrical, homes and other areas. I use their "Facilities Managers Costbook" in my commercial building restorations consulting work to help with cost estimates.
Brian, did you get an answer to this? We have a project and I just want to get a rough idea of sf cost.