Beginning April 1, 2022, you will also be required to have a rental license with a ‘hotel’ designation.You can find the bill details here and city FAQ for this here Cheers, Yuriy 

@David Shapira House hacking in Boston can be great but its more of an appreciation play then cashflow when you move out. 

(Owner-occupied)You can play with these on your county's tax assessor sight, estimating real property taxes for occupied/rental.If you want to get into the SFH space, and be competitive, I think your best bet is to invest in properties whose assessed value is sub $75k-$90k.

@Robert Vanecek not to play the devil's advocate, but what will the tenant do when a potential buyer brings their family through? 

I'd say make sure you have at least a 10% contingency budget allowed for any unseen freeze damage to play it safe.

Cheers...

More generally, how much does the building play into the appreciation of the condo?

Anything in a coastal market is more of an appreciation plan than a cash flow play.

While I'd never play around with safety issues, people who rent well below market have to accept well below average conditions. 

@Jacob Maes I know that some investors cash flow fine with condos in certain areas but it isn't something I'd be comfortable with because of all of the external factors that could be at play.