2-story add-on; attaching

jklingel

We are considering adding on to our house, and need some links/books to info on attaching the two buildings. Presently we have a 2-story, daylight basement and would be adding two stories on the daylight basement side, likely making another daylight basement place by filling around the new basement. My plan is to build the new building as "independent" from the old place, meaning a whole new footer/foundation wall. Once we get two stories up, the roofs will be joined, but I don't see that as being of any concern; looks straight forward. As we go, the sides of the old/new will be joined somehow, but that I think will be pretty straight forward, too. The question is joining the footers/foundation walls so that the two building operate as one. I envision drilling a variety of holes in the old footers/foundation wall and "gluing" in rebar that will extend out X" into the new building. Said rebar will be encapsulated in concrete when the new building's base is poured; footer will be of appropriate size, but the foundation wall will be quite thick so that it encapsulates the rebar stuck into the old foundation wall. That is my vision. Any opinions, links, books? I know this has been done 10,006 times before. Thanks. john

jomama45

What material(s) is the existing foundation & what will the new foundation be constructed of?

jklingel

Old foundation is concrete block, filled w/ concrete, 5 courses if I recall. We put it in back in 1980. Footer is concrete w/ rebar. New will be the same, except that I will likely use ICFs; laying blocks is not my favorite hobby. I am also wondering if, after joining the two systems, it would be advisable to lay another wall outside of both foundations, centered on where they join, maybe 20' long, like you'd scab on a board where two others butt against each other. Maybe that is gross overkill? Thanks. john