[djmcmath]

My wife and I are in the house-buying market. Many of the houses that are in our income range are just too small, and on lots that are tiny. The obvious answer is to expand upwards. Permitting questions aside (though I know those issues can be huge), I'm concerned about the engineering issues involved in adding a second floor.

The problems, in order of my concern:
1 - If the houses have basements, they're usually showing a concrete block foundation. Given the era (pre-1950, mostly), there's very little chance of rebar. Is it possible to add a story on top of that kind of foundation? What methods are available to reinforce such a foundation (assume that no shifting is readily apparent) to meet modern code for building another story?

2 - The walls for the first floor are, most likely, 2x4s. Now, given the era, they're probably actually 2 inches by 4 inches, but that's probably still insufficient to build on top of. What methods are available for adding strength to 2x4 walls?

3 - Many places have finished attics, and some even look like they were done to code. If the permitting guys have come through and said "This place is safe to finish the attic," does that imply that the foundational issues of 1 and 2 are mitigated?


I have a few ideas of how to deal with this problem:
1 - Build new. Specifically, pick a place with a big backyard and expand the main body of the house into it. Problem: permitting is liable to be impossible.
2 - Build new foundations for new posts which support the upper floor independent of the first floor. Problem: Expensive, in a big way.
3 - Tear out the walls, replace 2x4s with 2x6s, replace the walls. Problem: time consuming, incredibly messy, though perhaps less expensive than either of the other two options.

Thoughts? Anyone else ever done this? Am I crazy to even consider this kind of thing? Is it just right out of the question?

Thanks in advance,
Dan