Anything wrong with a furnace in the attic in a four-unit?

[Dan C.]

A four-unit I was interested in has one furnace in the attic.

Anyone know if there is anything bad about a furnace in the attic? Is it something I would want to correct right away? (I would be buying the property to hold, not trying to flip it).

There is definitely plenty of room in the basement for a furnace.

The four-unit is fully occupied.

The three other furnaces are contained within each unit. This is somewhat unusual around here, but I have at least seen it before.