A man cave

You know the man cave trend in homes? Well, I really think the trend has come and gone, but my husband, Carlos, never got his man cave, and he still wants one. Well, our two kids are now out of private school so we have a bit of extra money. For Christmas this year, I am going to give him his man cave! I am going to try to do it all without his knowledge, which is scary and probably impossible, but I am going to try. Anyway, I will be hiring people to renovate the garage and turn it into his own special place. I am scheduling it to happen two weeks before Christmas so we can be gone while everything gets done. I have hired a contractor and made all the decisions except for one major decision. What am I going to do about air conditioning? Is heating and cooling really necessary in the man cave? Of course it is! He needs efficient heating and cooling. Do I really need a furnace? I don’t really think so, but I might get a heater anyway. I live in the south, and we really use a/c about ten months of the year, so I am not certain about the heater yet. Is my current HVAC system large enough to handle the additional space? Should I just go really cheap and get a window a/c with heater? Should I go for the new thing and get ductless mini split a/c mounted about the door? I really don’t know what to do, so I am calling in an HVAC service pro to give me some ideas.