If you're not a professional, don't even touch anything structural in there. You can drywall and plywood over anything you want and it wouldn't cost much. Probably less than $200. A professional will cost a great deal more, but you have to live with whatever the outcome is. Just remember that you might need outlets, vents, light fixtures, windows, and other things you might not at first think of. And unless it actually stays part of the attic (i.e., there is a closed door that leads to it), you might be on the hook for getting a permit for adding an extra room or extending an existing room. That in itself can get expensive and time consuming.
ask a pro there are things like ventilation, space around can lights, length of duct work for fans and hvac systems ect. and like laduron says size and spans of ceiling joist. DEFINATELY DO NOT CUT ANY TRUSS WITHOUT CHECKING WITH SOMEONE THAT KNOWS WHAT THEY ARE DOING. Truss roof are engineered to work together with one another. There is a way to head out a truss properly to prevent roof sag/structural damage, $$$
My attic is not completed, it has trusses cris crossing the whole thing and loose insulation all over it. I know it would be expensive and a lot of work to complete it. My question is, would it be too hard to lay a floor down and add dry walled walls, etc. to a section of the attic ( about a 12x14 ft section right above my bedroom) without removing the trusses? Also, an approximate cost of the materials needed?
