I assume that your new home will have both superior building and insulation qualities.

Is basement below or even partially below grade?

I find the load calcs questionable particularly for heating. I suggest they be reviewed and retaken by a different person. Do you have these load calcs in writing, broken out for each zone, on the software letterhead?

Why a 3.5 ton AC condenser when load calc indicates a three ton?

If you expect good comfort and plan to use the basement regularly for living area, I would want a zoning control for that system. Well worth it.

Luxaire is sister company to York. Furnace appears to be top of line modulating model. I would want the Acclimate communicating control for best operation and full functionality.

Where will furnaces be located? If the furnace for second floor is to be located in attic, how will attic be insulated?

IMO

Thanks tigerdunes for reply and feedback.

Yes basement is mostly below grade, there's a french door walk out in the rear. Do have plans to finish and use the basement in the future. Builder mentioned using dampers for basement but should I request a specific controled zone instead?

Have load calcs in writing by zone but not on software letterhead. Will inquire to that. I assumed would've been a print out of some sort rather than sheet hand input. But don't know what's to be expected, typical practice with the load calcs.

Is there something particular with heating calcs that I should dig into with the builder?

Furnaces will both be in the basement. Builder was not keen on putting 2nd floor furnace in a separate mechanical room on the 2nd floor. Mentioned that would need to insulate duct work in attic

I also question the load calculations. I assume the first and second floors are each 2100 sq. ft. If that is the case, then how can the heat gain of the second floor be less than the first floor?

How much insulation will there be in the attic and exterior walls? What are the typical winter low and summer high temperatures?

Yes 1st floor is 2200 sq feet, 2nd floor 2000 sq ft.

All brick exterior. Insulation to be cellulose in house and garage (R-19) and attic (R-49). Closed cell foam on basement walls. Also 1" closed cell foam on exterior walls. Foam windows, caulk wall plates and in-between framing members.

The typical winter low temperature is low 20's with typical summer high temperature in the mid-80s'. Get a few cold weeks where in the teens and opposite in the summer where it does get 90+ for a few weeks at a time.

Yes, install a separate zoning control for the basement. Now is the time.

Yes, I think both furnaces are oversized. Makes me wonder if he sized the furnaces not for the heating BTU capacity but for the 4 ton rated blower that would be needed for the 3 1/2 ton condenser.

Yes, based on heat gain calc, a three ton condenser seems to be right size, not 3 1/2 ton as quoted. This should be questioned. Keep in mind, 36 KBTUs=3 tons.

I would want to know the design temperatures used both inside temp and outside temp both for winter heating and summer cooling.

You want excellent ductwork insulation for attic. That's a long way to blow air. You might consider an 80% furnace for second floor installed in attic. This would eliminate the long distance or perhaps insulate attic where it can take a high efficient condensing furnace without fear of freeze ups. The 80% would be a less expensive option. Discuss the options with dealer/GC.

Nothing is easy is it?

IMO

Yes did discuss with builder as to HVAC unit to be located in 2nd floor in separate mechanical room. Builder disagreed as required duct work to be insulated, heat loss in attic given winter cold temps we have in MI. I did not object as accustomed to seeing homes with HVAC units in the basement and did not read anything online where 2nd floor HVAC unit is a must.

Will inquire as to inside and outside temps used.

Based on your insulation values and the typical winter and summer temperatures, I feel the load calculations are not accurate. You need to dig into the details of how these numbers were calculated.

I agree with your builder about putting both furnaces in the basement. I have the same set up in my house so I know from experience the set up works and in my opinion it is more energy efficient than having a furnace and duct work in the attic. The key is to have adequately sized duct work running from the basement to the farthest room on the second floor. This should not be a problem with the size of your house.