Designing my first timber frame for my sister. need a lot of pointers...

[jesse1996]

My sister in TN is requesting I design her first home which is a big honor but also making me a nervous wreck on what to choose and how to choose it. She wants a three bedroom house with a two car garage sitting on a sloped lot of family land. So after some rough sketches an research I decided that an ICF foundation housing the drive-out basement and ruckus/storage room would be good for reducing foundation costs and labor. And then have a basic two story 22x45 rectangle house sit on top of that. She loved the modern barn look so I decided to look into a post and beam/timber frame home with some upgrades in a few departments. One being the ICF foundation, perfect wall system were rigid foam insulation is located on top of exterior sheathing followed by cladding which will be corrugated panels, Marvin windows to give it a modern flair, ideally include a double height great room at one end of the house, and zero overhangs on the roof to reduce material and give the building clean lines. She has a decent budget of $250k land already in hand. My main questions are:

1. How well do ICF foundations and timber frame/post and beam structures go together? 

2. can solid beam, LVL, CLT, or Glulam span that 22' area above the garage and possible also the second floor? Bonus if could even span 25' between the exterior columns to loosen the floorpan a bit. 

3. Any remote idea on how expensive the above building methods would be? which is the best between strength and cost? Price per square foot or even cost of similarly sized projects?

4. would it be more cost effective to just bring it down to one floor and have a larger foundation? or even just having timber framing in the great room and stick framing in the rest of the house to save money? (I'd prefer authenticity if possible)

5. are there any resources to find out what sort of spans I can realistically do? I've tried looking and I dont see many clear cut charts on typed of lumber and spans/loads for some reason. If I can layout the beam sizes and joinery myself I'd rather do that and have an engineer sign off on it rather than pay someone and hurt the budget more than it has to be. 

Literally any and all advice and information is appreciated. 

[Don P]

Hey Jesse,

1. They play fine together, I've done a couple on Superior Walls as well, a precast insulated foundation, might be worth checking on pricing/availability.

2. Solid, not really, LVL, glulam, truss floor, I joist yes depending on configuration. Residential CLT isn't there yet, but hopefully coming to a house near you soon

3. I'll let you know as soon as I come in on budget :D, you're tight.

4. It depends. Don't get too wrapped up in what is "authentic" in this world, its all just different ways of framing.

5. Hit the toolbox, bottom of the column on the left of this page. Don P's calcs>beam and column calcs. Also the WSDD (wood structural design data) on the awc.org website under publications.

6. you didn't ask but rethink the zero overhangs notion, overhangs do as much for building longevity and maintenance as anything. Your cladding is just that, the weather barrier is something behind that.