No it's not a private house. It's a very nice, new office building in a commercial part of White Plains.
Should I post pictures for you to see?
They don't own the building, so no it's not off the tax rolls.
So there are two parts of your post that are clearly false.
Shall I continue?
Please do.
What neither of us will know is what rent -if any is paid by that operation. The term "preferential rent' is often applied to charitable orgs. The landlord offers a low (in some cases no) rent and the difference is deducted from his taxes. That is how things like thrift shops and some cultural organizations survive in places such as NYC.
BTW: zeroing in on 29,000 posts? A true "man of leisure".
LCG