Expert: Bruce E. Johnson - 10/16/2009

Question
We live in a lovely 1912 bungalow which has stairs leading to an attic but the ceiling and roof are too low to frame any kind of rooms in. County records show that the property has 200 sq feet of "finished" area and 300 sq feet of "unfinished" area. Well really its all unfinished and definitely not livable. What would be an estimated cost to raise the roof and put some dormers in to make that upstairs into livable space and is it likely that the upstairs was meant to be used? In other words, was the foundation and 1st floor of the house constructed such that it could support an actual second story?

Answer
Hi Marta, making an attic into a living area doesn't really add that much weight to a foundation and support system of a house so I don't think that would be an issue in your case unless you were adding an entire new floor to the house.  However depending on where you live you will probably need a building permit which means that a structural engineer (P.E) will have to evaluate the house's structure and sign off on how the added living space is supported, tied together, etc.  If you wanted to take off the existing roof system, install a new floor system, frame walls and install a new engineered truss roof you will be looking at 100-125 dollars a square foot depending on how it is designed and what type of finishes and roofing are involved, whether there is plumbing installed, and how hungry the contractors are in your area for work. And as mentioned above there will be some design costs, possible architect involvement, definite engineer involvement, permit fees and the sort.  If your attic already has a floor system and you are just cutting large holes in your roof and adding dormers you might save a few dollars as opposed to an entire roof raising and reframing of the second floor but you can use the "rule of thumb" of 100 dollars a square foot for estimation purposes.  I hope this information helps please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com