Construction and insulation are most often left to idiots that build homes costing hundreds of dollars to heat or cool. Look to green building practices because they tend to match audiophile needs. Good houses are solid (Thermal mass), sealed, highly insulated from the outside, quiet, efficient and comfortable. Some can have highly integrated electronics that monitor heat and cooling systems. Most need active ventilation systems to bring in fresh air.
If you're not familiar with vapor barriers it's important to learn more or consult with a professional. Mold loves ignorance!