Expert: Dan Griffin - 3/25/2011

Question
I want to build a 3 room second floor to my one floor house.  How much does it costs to hire a professional to do it?

Answer
Henry, there is no way to answer your quiestion as there are far too many variables.  Just for a shock factor, I would expect to pay a minimum of $200/SF to even begin having a conversation.  If you will be living in the house when this work goes on, it will be quite a bit higher.  The costs have nothing to do with the quality or cost of finishes and hardware, but rather, the degrees of difficulty.

Think this through a bit.  You will be removing the existing roof.  You will probably lose the existing ceilings in the rooms due to wiring, adding heavier joists, etc.  If you intend to have any plumbing in the new upstairs, there will extensive work tying it into the existing.  A staircase takes quite a bit of room and demolition on the old ground floor.

I am not saying this cannot be done, I just want you to realize that this is a major undertaking which can require much more coordination than adding an addition or building new.  Working with an architect or a design professional will probably be your best point of beginning.  This will add some initial expense, but I think it will be beneficial for you and the builder in the long run.

If you have more specific construction questions, I will be happy to answer.