I have a wall that I want to take down to make my living room area much bigger. I know its is a 15 foot load bearing wall and know I have to get a beam but I don't know what size to get it. Also if my house is balloon frame work is it going to make it harder to put the beam in? Are the interior walls balloon frame? Or is it only the exterior walls?

I have never seen balloon framing on interior walls. Not saying that it is not done, just never seen it.

If going to the outside walls on balloon framing, have to bring support from foundation to under side of beam. This would require you opening up the walls to bring up support.

The size if the beam is relative to what it will be carrying and should be figured out by a building engineer or certified architect and approved by the building dept in your area.

Chuck