Cost of adding on a room (Yorktown, York: hardwood floor, how much, house)

[Londonlawyer]

I would like to build a den behind my house. Does anyone know the approximate cost of adding a 20x20 foot room onto the house?

Also, how much do the taxes go up?

[czarinalex]

Don't know the cost of adding on a room.....
BUT.... we discovered that any time we did any work to our house that required a building permit, our town(Yorktown) took that opportunity to reassess our WHOLE house. A couple of relatively small improvements and our taxes are high.

[bmwguydc]

There are a few variables, some of which are town specific, that can affect the overall cost of adding a room. Others are in your control as to the materials used for the construction of the room. For example, if you use a an oak hardwood floor as opposed to an exotic hardwood, the costs can be vastly different. Will the room be on a slab, crawlspace, or basement? Will it be constructed of stone, brick, stucco, or siding? Do you have an older, architecturally distinguished residence for which design considerations are more pronounced? For resale, the degree to which care in planning and design of an addition on a distinguished residence can make a huge difference in the return on investment.

A guess as to what you'd be looking to spend on the low end would be $35-45k for a relatively simple room, but more than likely you'd be close to $50-60k for a quality job using good materials. Anything exotic in materials or design such as a vaulted two-story ceiling with skylights and beams, might put you to a higher figure ($80-100k+) for the same 400-square foot room.

Talk to a few contractors and architects to get a good baseline cost per square foot for a basic room and then upgrade finishes and features from that price.