Update House CAD for Snow Load

I already have complete 20' × 24' house plans in .dwg format; I now need those drawings revised so the building will safely handle Yakutat, Alaska snow loads and reflect a few design tweaks. Scope of changes • Roof structure: switch the current dimensional-lumber rafters to I-joists... (Budget: $750 - $1500 USD, Jobs: 3D CAD, AutoCAD, Building Architecture, Building Design, Building Engineering, CAD / SolidWorks, CAD/CAM, Drafting, Solidworks, Structural Engineering)