I’m planning to build a timber frame home soon (eastern white pine and SIPs) and have received a decent quote for an ICF basement.

I like the idea of efficiency in this combination and know that others have built this way but am a bit confused about how they connect? We are responsible for the foundation and first floor decking before the timbers arrive.

Does any one have construction details they could share for this (ICF wall, sill plate, first floor deck, post, blocking, and SIP positioning)? If not can any of you share your experiences with this?

Here are the specs on our materials:

Eastern White Pine post = 10″-12″ thick

7 3/8″ Neopor R-38 SIPs = 8 1/4″ thick (with OSB)

ICF wall with 8″ concrete = 13 1/4″ thick

Our timber frame company said they need at least 6″ of concrete directly below the posts. Is this enough? I’ve seen that some folks float the sill out to support the bottom of the SIP panels but it seems like it would require an extremely large sill/overhang on the outside?

Any and all input, guidance, and links are greatly appreciated!