Building a shop as part of a construction loan?

I'm doing the same thing right now. My builder told me to get the specs and a drawing of the shop and he would add it to our bid (He is not building the shop). I am running them as separate projects so we won't be pouring slabs the same day. My builder will pull my permits and my shop builder will contract the shop.

As far as the loan goes, they will add it into your mortgage and you will draw on it like you will for your house materials.