Heating in the attic? Advantages and disadvantages? New heating system?

Hello, we want to buy a house where the heating system is in the attic. What are the advantages and disadvantages of this? Also, it is a gas heating system from around 1998. We want to renovate the house and this should also include a new heating system. In the future, we want to be as independent from electricity and gas as possible. What would you recommend and how much would this roughly cost?

P.S. The house is approximately 125 sqm in size

We want to be as independent as possible from electricity and gas in the future.

Maybe "oil and gas"? Being independent from electricity is a real challenge. Since the heating system is located in the attic, using wood will probably be very complicated. The pellets would all have to be pumped up to a storage area. That leaves only solar-powered water tanks (solar energy) or heat pumps (which also require electricity, though...). A heat pump can also be installed in the attic. However, this will not harmonize with the installed radiators, as heat pumps usually operate at a very low heating temperature. Gas heating tends to be higher. As a result, the heating surfaces of the existing heating system are probably far too small (radiators or underfloor heating). You see: Without a professional/planner, it won't work. Simply replacing the heating system will not work.