We are going to build a small addition off the back of our home. 15X15. We have a deck there now (floating, not attached to the house). My question is what foundation type would be recommended? Stick built, 3 sliders, mostly large windows in the walls, shingle roof and vinyl exterior.
Options I've looked at are:
Helical Piers. Approx $1600 per pier X 6 which is going to end up over 10K. Seems nuts for this, but that's what I've been told.
Sonotubes/concrete piers. Might cost us $3K for these
Footer/poured concrete with above grade crawl space. We are in the north east so footers have to be 48" deep. We can do this for around $6K
Any other options I haven't thought of that might make sense? Any of these 3 recommended over the others? Cost isn't a big concern, but obviously whatever I save here can go to upgrade the room features.
Thanks