All functional just like 1980 old.

I've been in the building about a month or 2 ago to price out work and it's actually still functional.

If the furnace had some specialized function, such as in a climate controlled self storage facility, then it could be a 5 year asset. 

But if they are high functioning and able to function close to normal then yes I would.

Second story or extension to the original house with a fully functional “wet bar.” 

And the award for most diligent use of the @Mention function goes to ...

As Basit Siddiqi mentioned, its tough to house hack in NYC and live free.I’d suggest you use BP’s search function or set up keyword alerts to see what other folks have to see about house-hacking and other topics you’re interested in.

Back to the secondary admin account: the "second" admin account can't do all admin functions (i.e. payments etc.) - so it really isn't an "admin" account.  

Unlike multi-family (5+ units) where the value is a function of the income, the fourplexes appraise and appreciate like single family homes.

Of course, few people have friends who are willing to functionally give away 5-figure sums – there’s always a quid-pro-quo or payback of some sort, somehow, somewhere.Oh, but the IRS will never figure it out!