I am doing an addition/renovation on my current house. It will be done in two stages to meet with requirements of the local building codes as well federal guidelines. The house will be taken down to the studs and re insulated new windows and the whole works. We have a new condensing boiler that feeds an indirect water heater and 60 year old Radiators. There is no AC currently.

I have talked to a few people but I do not even know what is out there for options and what makes the most cost effective heating and AC system. Thank you for any thoughts.