NEW YORK CITY

Online building-wide communication systems — the kind that tell you who's at the door, when your packages have arrived and who's bringing drinks for the annual meeting — seem like a godsend to some buildings.

But be warned. While these systems can be a boon for communication between the board and residents, non-essential information (like that drink assignment) can turn into ad hominem attacks: "Did anyone else see Judy spike the punch??" Could the board actually be held responsible for intra-building gossip?

We represent a 120-unit co-op originally sponsored by the New York City Department of Housing Preservation and Development (HPD). After years of alternating between occasional discussions and benign neglect without any definitive action taken by either party, this limited-equity Housing Development Fund Corporation (HDFC) cooperative received a notice that it was in default because it had failed to pay HPD a portion of the profits earned upon the sale and re-sale of apartments. Simultaneously, the city agency notified all shareholders of the default, creating a fear that the building could face foreclosure, leading to a loss of residents' homes and equity.

Nearly 40 years ago, New York City began taking over derelict apartment buildings and selling units to intrepid homesteaders for just $250 a pop. Thus was born the Housing Development Fund Corporation (HDFC) co-op, designed to be affordable housing sold at token prices to New Yorkers with incomes below a certain limit.

The City now charges $2,500 for such HDFC co-ops — but some of those who rightly took advantage of the City's deal now are selling their apartments for close to market rate, which as this DNAInfo.com article points out, goes against the spirit of the working-class program, and making what are supposed to be affordable apartments unaffordable. It's not against the law, though, and so now a City-appointed task force will be recommending legislation to keep HDFC affordable apartments a reality.

A BUYER ASKS: A broker just showed me an apartment in a building that’s perfect for me. Then I did some research and found a website that tracks bedbug infestations —  and the perfect building is on the list. What should I do? Should I abandon the apartment? What happens if I do buy it and the bugs come back?

A BUYER ASKS: I want to buy a co-op apartment on the Upper West Side, but when I looked at the building's financial information, I saw that its underlying mortgage is going to expire in two years. Does this matter?

A BUYER ASKS: I have an opportunity to lease a storage bin in the basement of my co-op. It's much cheaper than an equivalent space at commercial storage facility, but with an outside facility I know I have certain rights in case the contents of my bin get damaged by, say, flooding — an issue that doesn't come up with a commercial facility if I get storage on a floor a few stories up. What are a co-op's responsibilities in terms of storage bin liability?

Once you start down the path of buying or selling an apartment, it's inevitable that you'll hear horror stories from well-meaning friends about their own ill-fated excursions and The Deal That Got Away. Getting rejected by the co-op board is always a popular one. But as BrickUnderground.com writes in an eight-point article, you might also find yourself the victim of a buyer or seller backing out at the last minute, or a higher bid coming in at the last minute, or several other things that can make you want to fast-forward past that last minute and wonder why last minutes even exist. But if you know what to expect, maybe you can prepare for and even avoid such swerves. And if not, hey, at least you'll have horror stories for your friends.

The neighbors thought the smell came from rotting human remains — that's how bad the odor was that emanated from the locked apartment. An anxious co-op board ordered the super to break in and, to everyone's relief, it was only a cat —  one that, apparently, had been left unattended for some time and had been using the entire apartment as its litter box.

Median prices for Manhattan condominium apartments have increased more than 55.4 percent over the past decade, from $804,000 to $1.25 million. Townhouses have spiked less, rising just 33 percent, but the dollar amounts are way higher: $2.7 million to $3.59 million. Ah, but with a townhouse, there's no condo board, and no one telling you that you can't lease a portion of the place, so there's potential rental income to help offset the higher price tag. And you save on the monthly common charges, though you might well find yourself spending about the same on upkeep. Condos, on the other hand, have apartments above street level, which are generally safer and quieter, and often amenities like a gym or a roof deck. And there are subtler points to consider as well — all ably delineated by Leigh Kamping-Carder in "Ask an Expert: Condo or Townhouse — Which Is A Smarter Buy?," the latest installment in BrickUnderground.com's weekly roundup of authorities on various subjects.

Here's a scary scenario: Sales take a nose dive in your condominium because potential buyers fail to qualify for mortgages. Or worse, existing unit-owners are unable to refinance their mortgages or take out home equity loans. With mortgage giants Fannie Mae and Freddie Mac tightening lending rules, condos are bumping up against hefty reserve requirements that, unless met, will kill deals.