2 X 6 exterior walls, foam filled. Fill every drill hole in the 2 X 6s that carry elec wire with foam. Use pink batts for interior 2 X 4 walls for sound.
Use R-60 blown cellulose in the ceilings. Design big overhangs to protect interior rugs and furniture.
Consider a geothermal heat/cool system. Ours has a thermal floor switch for the coldest months. Add a energy recovery ventilator for cooking or when you have a houseful of guests. Put the switch in the kitchen.
Best double glazed windows. Don’t go cheap. Andersens stand out. Ditto Andersen exterior doors. Double wrap the house corners with white foam sheet. Corners are where most leaks occur.
Good luck and make sure the builder has experience with geothermal...
Consider an exhaust fan for the roof to keep the attic cool.
Add a 1/4 hp circulating pump to your hot water heater. Saves water and gets hot water to where its needed without wasting fill in the pipes.
Interestingly, the builder has geothermal in his house and recommends against it. Thinking about it from a re-sell perspective.
We prefer Rockwool rather than fiberglass.
It’s more expensive but very good and helps with sound.
Foam is in there forever and makes adding anything very difficult. You can’t feed something through the walls later if you want to add something.
“2 X 6 exterior walls,”
That is what we did plus brick all the way around. Worth the extra cost. That extra 2” of insulation does wonders. Plus we have geothermal. Our heating and AC cost is minimal.