you would need to contact a contractor. A house building company will want you to build one of their designs. They would not build anything else. A privet contractor will build anything you have engineered. as a matter of fact, they would be pretty fair in price right now with the building market the way it is. You would need someone to draw your architecturals and then have them engineered. You give those engineering plans to permitting and then to your builder. depending on the square footage is how the prices for these two steps run. This is seperate from your building costs. Decide what you want, then call around. You need at least a sqaure footage to get a price. I work for a structural engineer.