For the past two years, my father has been sick, and he moved out of his stabilized apartment and into an assisted living facility. In hopes of keeping the apartment, I had my niece move in, but I just received a letter from the landlord saying they're not renewing the lease because my father has not lived there for 183 days of the last year. Can I fight this?

Unfortunately, your landlord is likely within their rights not to renew your father's lease, say our experts.

Your instinct to move in a family member was smart, but not legally binding in this case.

For one thing, after a 1997 ruling, nieces, nephews, aunts, and uncles no longer qualify to succeed a family member's rent-stabilized or rent-controlled lease, says Sam Himmelstein, a lawyer who represents residential and commercial tenants and tenant associations.

And she'd had to have been living in the apartment for quite some time while your father was still there to make this work.

"The resident [in this case, your niece] would have to be a recognized family member of the legal tenant [your father], and have cohabited in the apartment for a period of two years," says attorney Jeff Reich, unless your niece is over 62 or disabled, in which case the period would be cut down to one year. "Since it doesn't appear that the legal tenant and his grand-niece co-habituated in the apartment for any period of time, it doesn't appear [that you] have a good chance of winning this fight," he adds.

That is, unless, your father could potentially be well enough to move back in himself.

"When a rent-regulated tenant leaves an apartment to go into a hospital, nursing home, assisted living or rehabilitation facility, the courts are, correctly, reluctant to find that the apartment is no longer the tenant’s primary residence unless, based upon objective medical evidence, the tenant does not have the ability and desire at some point to return to the apartment," says Himmelstein.

The length of your father's time in assisted living would seem to indicate that he's either unable or unwilling to ever return to the apartment as his primary residence. But if this isn't the case and he does have plans to return, you could push back against the landlord on those grounds. Your niece, however? She's most likely going to have to find a new apartment.

Virginia K. Smith is the senior editor at BrickUnderground.com, the online survival guide to finding a NYC apartment and living happily ever after. To see more expert answers or to ask a real estate question, click here.