How do I tie a new addition wall into the existing structure?

A lot depends on the materials used in the existing wall, is it stud framed or masonary.

Remove siding on old wall and add a stud from the new framing to the old.

Well Mike that's my thinking too but what if this is a brick home? I have been waiting for the other Mike to answer.

Thanks Guys, I pretty much thought I'd just remove the siding and add an angled stud to the existing structure (I also thought I'd use hurricane staps to stiffen the joint). The addition will be at a 45 degree angle from the original structure and I should have told everyone that and did not know (I've been serching the "Code" to see if an additional support was necessarey.

At the foundation, I was goint to drill holes and reinforce the attachment with rebar. The foundation will be left to pros.

When the pros pour your foundation they can add anchor bolts during the pour, ask them ahead of time. You bigger challenge may be creating an opening between the old and the new since you be b cutting into a load bearing wall. Have you talked to your building inspector regarding what kind of plans and details he requires?

Actually, since the "code" is not that clear, your suggestion was my next step. Construction is at an all time low in our small town, so I'l probably be able to get some help with the rough in with out breaking the bank. Thanks to all.

Mike, code may appear vague but its crystal clear to your building inspector. Maybe you can sub in a out of work pro to do the load bearing work.

Thanks for the suggestions. The local Bldg Dept suggested that I do a full perimeter foundation with a full wall above. I would no longer have the problem with tying into the LBW. I'm not to keen about having a 12" wall to have to cripple or head for the 2nd story hallway. My mudding and dry wall skills are excellent but I know that I'l overbuild the addition and both structures will "settle at different rates. I'l be resurfacing cracks forever.

I'm also concerned with exposing that much of the existing foundation (28', entire west side) to the possibility of failure just to repour another foundation.

Should this concern me?