I live in a four-family apt building w/915 sq. feet of EDR (I believe that is the correct terminology). Contractors who have come out for estimates have recommended the same brand of boiler. One size in the brand line makes 900 sq feet of steam, and the next size up would create 996 sq feet of steam. I mentioned this to a friend, who said I don't want a boiler that is too big. So my question is which size is a better match?
One more thing. As a practical matter, there are units that do not turn on all radiators in the aptments because it gets too hot. On the other hand, there might come a time when the unit changes owners and the new owner wants to use all available radiator heat.