What would be the easiest option to create an architectural belt on an ICF wall? Something similar to this picture http://i2.wp.com/zecaph.com/wp-content/uploads/2016/09/propunere-9.jpg?fit=1280%2C1024 The belt would be anywhere between 4 to 16 inches wide and about 10 to 14" thick. Besides the aesthetic aspect will also serve to shed against rain and snow but that is secondary. I would attach a ledger board on to the ICF wall and screw in some metal brackets that can then covered with wood and metal sheet, etc. Or build the brackets out of wood. The condition is that the top of the belt would be virtually horizontal (1/4:12 pitch) so it should be strong enough to support 3 ft of wet snow build up. Another option would be to build it out of a 4" thisck concrete and add L shaped rebar into the wall to support that small cantilever structure. This option would be more solid from a structural stand point but also more involved during the ICF wall pour. Will also need to cover it in foam to prevent thermal bridging and attach some additional wood pieced to reach the overall desired thickness, etc. What other pros and cons do you see to either option or how else would you do it?

I think that the approach to framing the belt is mostly dependent on 2 variables. The first being the thickness. A 4" protrusion would be much simpler than a 10 to 14" one (mini cantilever). The other is cladding choice. Will that be stucco, vinyl, fiber cement?

Maybe a few more details will help folks on this site think up some solutions. First glance leads me to believe that a 10 to 14" protrusion would require a careful framing plan and introduce other things for consideration, like flashing.

The cladding of the ICF will be stucco. The belt itself will be covered withsome foorm of metal cladding.

I am also thinking of placing two ICF hangers for each joist such as Watkins hangers - one for the joist and one for the member supporting the joist at an angle then run a board across the open end of the joists to create the box.

For a 4" protrusion only I am also thinking to create it out of EPS and attach it with glue or screws or both.

Before I went with additional Watkins hangers (spendy) I'd research the possibility of being able to hang your box on the ICF webs. Depending on the spacing for your particular ICF you might be able to build your box out of common framing lumber. That would make the top slope much easier.
Why the metal cladding? If your using stucco for the body, I think that would be the finish I would go with and incorporate paint if you want the belt to pop out. I'd also check with a stucco guy and ask his opinions. They are doing some pretty clever architectural elements these days. He might even have some better ideas for the frame-up as well as idea for flashing and weather proofing. Good Luck.

attach a 2 lb density foam shape the the ICF exterior with adhesive

I agree with Chris. I've done something similar a number of years ago. We cemented a 12" x12" band on an icf build. It's still there even after a 30" snow fall on Mar. 14th of this year. The trick I use, if you promise not to tell anybody else, is to glue the foam with silicone caulk. I buy mine from Wally world. Holds better than anything else that I use. I think your over thinking this. Keep it simple. We also double meshed the area as a belt and suspenders back up plan.

Thanks much for the input. Sounds like the foam belt properly flashed may be the easiest way to go.

Thanks much for the input. Sounds like the foam belt properly flashed may be the easiest way to go.

I like Loctite Heavy Duty Power Grab adhesive

One thing I forgot. When you glue to a molded block, rasp or use a wire brush to break the surface open.

Obviously the glued area. EPS density and the actual shape would make a difference but I can't stop thinking that sooner or later someone will try climbing, stepping on or hanging on this protrusion since it will look like a solid part of the wall.

So the natural question that comes to mind is how strong would be such an EPS shape glued to ICF and stuccoed?

This can be done with a beveled ledger. Long point of the ledger to the outside. Build the box and attach a cleat with the same bevel attached to the box, with the long point of the bevel towards the wall. Insert box and bevel into the ledger bevel from above. The bevel and gravity tightens it up. Screw to ICF webs. Flash and finish coat.