NEW YORK CITY

Baby, it's cold outside, and your boiler and heating system are going full-blast. That's a big energy cost for your cooperative or condominium. Fortunately, you have options. With supplies of natural gas high and prices low (though higher than last year), it may make sense to switch from oil to gas — or perhaps to to a dual-fuel burner capable of operating with either. In our latest Teachable Moments column, two veteran property managers relate some real-world experiences of how they helped their co-ops and condos pull the trigger on pulling the switch. Did it work? Well, one place is saving $50,000 a year and others are saving six figures. Might be worth the energy to consider.

New York laws place absolute liability on landlords in cases of accidents. Therefore, co-op shareholders, condo unit-owners and boards of both types of buildings need to be absolutely sure that contractors they hire have proper insurance coverage.

Any apartment-owner hiring a contractor must complete an alteration or a decorating agreement and have it signed by the board. And a contractor must provide a certificate of comprehensive personal liability and property damage insurance policies from its insurance carriers, generally in the amount of $1 million, that name the shareholder, the co-op or condo and the managing agents as additional insured.

Have you taken a look at your building's website lately? Co-op board members are busy people, so the building website may be last on a long list of priorities. But if your building website looks dated and isn't user-friendly, maybe it's time to revamp it. The bottom line is that if it's not intuitive, it won't be used. Here are some tips on how to get started.

For example, if a worker is injured while working on the building's façade, he will probably sue his employer, the building he was on, and the managing agent. (With regards to any claim against the employer, the worker must first seek relief from workers' compensation — and that award is eventually deducted from any other judgment.) The problem is that if the contractor's insurance policy is deficient in some way — he told his insurer that he is doing carpentry instead of façade work, for example — the insurer will deny the claim. That can leave the building open to liability, despite an indemnification clause.

You can call them pocket listings, whisper listings or off-market listings ... but chances are you won't be able to call them anything because, really, what are the chances schlubs like you or me are going to get tipped off to an unpublicized, unlisted co-op or condo apartment for sale? Well, our odds just got better with BrickUnderground.com's three-part "Guide to Elusive 'Whisper Listings'," here, here and here. That's a lot of whispering. There's advice for both buyers and sellers from brokers and attorneys, including how to tell if the seller really does have a deed to the Brooklyn Bridge, or at least to that nice apartment Down Under the Manhattan Bridge Overpass.

A READER ASKS: I just bought a gorgeous condo unit in a building overlooking Central Park. Recently, I got a letter that read, “We represent Component Assembly Systems, Inc., a subcontractor [on a project in your building]. Please find for service upon you a copy of a Notice Under the Mechanic’s Lien Law filed in the office of the Clerk of the County of New York on April 3, 2009.” The lien is for $8,334,400, and apparently I’m responsible for a proportionate share. What is this?

FrankieD writes: Last year our co-op board met for the annual election and after that meeting, they were never heard from again. Nobody knows who the president is and there has been no communication at all. Is this a violation of co-op bylaws or just stupidity?

Even the best-financed condo and co-op boards can feel a strain on their budgets. With so many fixed costs, boards have few places where a budget can be cut. So why not try saving money through bulk purchasing? There are four areas where it's most feasible: electricity, insurance, cable television and physical items like appliances and windows.

Talk about your real estate being underwater: According to a new report by New York City Comptroller Scott Stringer, updated flood-zone maps from the Federal Emergency Management Agency (FEMA) cover 84,596 structures in the five boroughs, up from 23,885 in the 2010 maps. That comes out to 400,000 residents, the report says. These newly analyzed flood insurance rate maps (FIRMs), which were proposed last year and are awaiting federal approval, could increase flood-insurance rates by as much as 18 percent per year for similar levels of coverage, the report says.

And more increases could be coming since, the report adds, "The currently proposed maps, which are due to take effect in 2016, were initiated in 2010 and as a result do not even take into account flooding patterns observed during Superstorm Sandy." The report urges the City to invest in "resiliency projects that will safeguard our shorefront communities," valued at $129 billion. It's also a whole lot of people's lives and livelihoods. On the other hand, there are also a lot of luxury waterfront apartments — so should taxpayer money also protect those private developments with deep-pocket owners? Just asking.

You're a co-op or condo board president and most of the residents in the building don't really know the super, the management or even one another. How can you go about bringing people together in your building and beyond? Here are some tips for creating a sense of community among your residents.