We are in the process of purchasing a new home that has a basement. Due to our budget restrictions we plan on taking the standard vinyl flooring in the kitchen from the builder but have plans to replace it with tile after an year or so. The problem now is that the builder says that we need to get the double joisting done now as a structural upgrade in order for us to tile the floor at a later date. Can a professional we hire to do the flooring take care of the joisting part or no? If so how expensive will it be?

Is double joisting a must for getting a tiled floor or is it because we have a basement?

Appreciate if some one can guide us through the right information.