"BigLar" wrote in message
...
I understand that this is an open ended question with probably lots of
"it depends" variables, but I don't have much experience with building
and thought I would toss this out. We want to hire someone to add
approximately 700 sq feet onto the back of our home. Our house is
modest size with the back exterior being 35' across. We would like to
extend 20 to 25' feet out and create two evenly proportioned rooms
with three windows total and a back sliding patio door. We want
electricity of course, but no bathrooms or other plumbing. My question
is: can anyone provide a ballpark estimate of the cost of having that
done? I'm picturing a slab for a foundation and would like a fairly
seamless continuation of the siding and roof. We are going to get some
estimates and were hoping to come in at 20K or less. Does that sound
reasonable?


No plumbing? What kind of heat do you have? It may require a larger boiler
or furnace and associated plumbing to handle the add on.

What is the roof style and how is the new addition going to blend into it?
You may need extensive work with trusses for that 25' span and drainage from
the existing roof. The existing exterior wall may need a fair amount of
work to change window and door locations, close in existing windows.

I can see you spending 2 or 3 times your estimate.