I'm building a new house and want to thoroughly understand how to properly insulate a house.

Right now, I'm leaning towards doing 2" XPS over OSB, over closed cell foam insullation. But where should you put a drainage plane? Some online articles say to put the drainage plane on the exterior of the XPS, and some articles say to put the drainage plane between the XPS and the OSB.

How do you determine where the drainage plane should go? The home will be in Cleveland, OH.

The drainage plane goes directly under the siding. It's purpose is to ventilate the back of the siding. Installing a (cold) vented air space behind your exterior foam renders your exterior foam useless. Instead, you want it attached tightly to the insulated wall.