So, it is now essentially a blank slate -- meaning that I can design all of the rooms and future layout however I want it to be, but taking into account where the stairs are located and where the exterior doors and windows are located. The first floor and second floor have full-height ceilings throughout. The third floor is large, but it has some sloped ceilings due to the roof above. And, I should add that the plan includes that all of the exterior walls will be framed out on the inside of the building and insulated since the exterior walls are just masonry/stone right now. And, of course, all new frame-out windows will be put in since all of the interior window trim was already removed in anticipation of that.
The house has (or, should I say, "had") hot water cast iron radiator heat. All of the cast iron radiators are still in place, with any iron piping that goes to the radiators still there. The gas boiler for the cast iron heating system is only a few years old (I had it put in when I bought the place and converted from oil to gas heat). There is no central air conditioning.
My decision now is:
1) Do I design the whole new house layout based on using the existing gas boiler and keep the hot water cast iron heating system (which would mean running new copper lines to the radiators)?; or,
2) Should I just take out the existing gas boiler and start over with a gas-fired forced air central HVAC system?
I don't know the cost of installing a whole new central HVAC system including all of the duct work throughout the whole house. And, I am wondering if a central HVAC system will have any issues pumping enough air (especially the AC air) up to the third floor.
Of course, I can have a couple of heating/HVAC contractors look at the shell and give me their opinion and a rough idea of the comparative costs -- and I probably will be doing that anyway. However, since I don't even know what the room layout of the house is going to be yet, the most that I could expect from them right now is a very general idea of the pros and cons of each option.
I'm leaning toward going with a whole new gas-fired forced air central HVAC system and using the theft of the copper pipes as an "opportunity" to switch to a central HVAC system rather than to try to restore to old hot water cast iron heating system.
Any ideas, thoughts, or suggestions that others here may have about which way to go with this would be appreciated.