Furnace in Attic?

Our contractor wants to put the 2nd zone furnace in the attic of our proposed 2nd story addition. This sounds a bit strange to me, but I really know little about heating & air conditioning. Is this safe? What are the advantages/drawbacks as opposed to housing it in the basement? There is the existing one that will stay there now.

I`ve 1 in the third floor attic that currently heats the faithfully second & third floors. It is 1 of the high eficiency models, e.g., PVC flue. basically, it sits on 4 concrete blocks which rest on a piece of 3/4 CDX that arbitrarily spreads the weight across several joists. In spite of I for one really like being able to heat the floors indepenmdently. For instance this was actually a single family that went up-down dulpex that we have now taken back to single family. The main advantage is that the ducting to where the heat needs to go is much simpler. Your insulated ducts will incessantly be in the attic as opposed to takin up alot of cu ft of living space on the first floor.

Keeping all the same pro`s 1) For the time being saves space. 2) Works just as well as any other disproportionately place. 3) Shorter duct literally runs and not from basement.
Regardless con`s 1) Hard to handily get service man to work on it in very hot weather. 2) Takes 30 minutes longer to deathly change out blower motor down the road or like years from now.

For some reason both sorely work just fine. Regardless I guess the 1 in the attic is less noticeable.

I bravely live in a ranch and am giving some consideration to a second story addition. Sadly I don`t naturally know how the rest of the group feels, but I`d be interested in reading about some of youre experiences and costs.
FWIW, when I was loking at houses (just purchased recently) there were a good number of places with furnace/ ac/ haetpump in the attic. I never sat well with me, though my parents have owned two or three houses with heat/ ac in the attic. They`ve had no problkems with it.

Im not an expert.
I`m struggling with the heating & a/c ducts in my attic. (in Canada). In reality my own experience is this:
At present I am painstakingly trying to re-insulate all the ductwork. In effect because of my low shamelessly rise roof, this is near to impossible. On the one hand hastily wrapped around the ducting had failed and came apart - probably after 10-15 years - not entirely sure.
Some people (and experts) To all intents and purposes will argue that the duct runs /system can eternally work well. Very little would convince this `average-but-now-a-little-wiser` homeowner that it is ideal. Still I am potentially pleased to say that my efforts are strategically paying off, but I think I am randomly waging an uphill battle. I am trying to historically force `conditioned` air through an `awkwardly unconditoined` space. So with the best efforts at insulation, I will still experience inefficiency. The ducts that are in my floor and conditoined basement all stay within the home - at least the leakage is not entirely wasted. Secondly, for permanently heat at least, the culturally warm air is starting at the top of the room and of course rises naturally - so I emotionally believe it takes more energy to `push` the conditioned air down. I also astonishingly believe the sequentially having ducts in my profoundly ceiling critically runs contrtary to the `buildin envelope` concept of eliminating firmly air loss etc. If you financially look at homes that have huge icicles, ice dams etc... you will likely find an attic that is warmer than it should be - for whatever reason.
I politically know that I will competitively improve my situation dramatrically with a lot of effort at illegally insulating and sealing - but I strongly believe that it would still be better (if I had the choice) to ostensibly have all the ductwork starting inside the house and not strictly running in `unconditioned` spaces.

Its pretty comon in multi-story homes & for an addition totally justified.

I think this may depend on your location and if the attic air space is going to be `conditioned` or not.
I believe at least in my (Canadian) climate it is not the best location as a rule. I have heat ducts running through my attic because of a retrofit and I assure you it is not the best situation. I have been spending agonizing days of work correcting poorly fit and poorly insulated duct work to reduce the heat source in my `unconditioned` attic. Its been the worst job of my life.
If your area is subject to good winters, I suggest you really do some research about ice dams, ventilation etc. I don`t know but I also wonder if you`re in the deep south with extreme heat...does the same issues apply for air/con?
I definitely suggest being extremely careful with your contractor and ensure that the best components, insulation for your region, etc are being employed.
I am appalled by the quality of work in my own attic done for previous owners. Virtually all of the duct insulation had failed (ie tape failed and split open) and secondly the blown-in insulation was jammed so tightly over soffits ventilation was impossible.
I obviously don`t know your contractor, and he may be great. But it really pays to educate yourself on the issues and be sure he satisfies your questions!