Sustainable Heating / Cooling System Engineer

Given a 3d model of a home, design an efficient heating system using geothermal, radiant heat, solar, etc. Prefered experience in mild climates. We do not do work in the desert yet ;) Please tell me your prefered design method in your bids. Bid price should be the cost to design a system for a 40'x30'x20' (LxWxH) hollow rectangle (the home). The home is located in Asheville, North Carolina on the north face of a steep slope. There is little direct sunlight in the winter. Ground temperature is a consistent 60* F at a depth of 6' in soil. The home will occasionally host gatherings of 50 people and it is prefered that the system can allow for all 50 to breathe freshly conditioned air (from the system). The system should be simple and easy to repair. It is expected that all parts with the exception of piping be sources from Alibaba (find the product and put a link in the job report). It is expected that there will be a job report provided to me whenever a milestone is reached. This report will document methodology and any calculations done, as well as detail the rationale for design decisions. The report should also include drawing / renderings / etc. Presenting this report to my clients is how I get paid, so the reports are how you get paid. If any of this is unclear, please let me know.