How can we both have Heating as well as A/C

My husband and I both need a shed for different purposes.

I use the shed to work out in and my husband is a pack rat. He wants the shed to put tools, grass equipment and garbage he can’t area with. I can’t let him in my shed or he would take over. The tools would consistently kneel in my work out section and I wouldn’t have enough space. So now my husband needs to build a shed for himself. He is planning to fasten right to a single of my walls. We will be separate buildings just sharing a wall! Doing this ensures that he can share electricity and the water lines with me. My husband also is hopeful that he can get Heating as well as A/C equipment that starts in his shed and extends all the way into mine. I have to admit, the thought of having Heating as well as A/C in my space is awesome. I am not sure how a Heating as well as A/C company can do this though. He could install air duct that stretches in a single ceiling, goes through a wall and goes up into a different ceiling. That sounds care about a lot of work and a lot of injure could be done. I am thinking a better solution would be a ductless option. My husband could have the outdoor equipment behind his shed. He then would have a single indoor air handler in his space and I would have a single in mine. We would both fasten to the same outdoor equipment however at different points. With this method, the multiple of us can set the control equipment differently and it won’t matter. I also think it would be easier to install.

Air conditioning worker