Where do you live (i.e. what's the climate like), how is the shop/garage insulated and what temperature range is tolerable? Also, do you have natural gas, LP or fuel oil available, or just electric?

Hello lily5 and congratulations on breaking ground for the new house!

If this will be an infrequently used space, consider a ductless air conditioning and heating unit. It will save space and can remove allergens (and dust from the workshop activities).

Since this is for a hobby area, would you plan to heat the garage otherwise? You may even want to use a portable air conditioner with heat option (use a garage window for the exhaust). During peak heating or cooling times, the unit could be wheeled into other parts of the home to provide additional comfort.

Best wishes and happy groundbreaking!