WASHINGTON HEIGHTS

Nigen and Yvonne Vosper lived at 555 W. 160th Street in Manhattan on December 24, 2008, when Nigen slipped and fell on ice as he was leaving the building at 7:55 a.m. Note the time, because it becomes important. The following month, he filed a lawsuit for personal injuries, alleging that the building had "created a dangerous and hazardous condition on [the] outside landing by removing a step that was there and replacing it with a downward sloping landing, without a handrail."

Under Local Law 84 of 2009, large buildings must record and keep track of their energy and water use — and then the city posts the results for all to see. The letter grades are linked to a numerical score called the Energy Use Intensity (EUI), which measures the energy used by a building per square foot, per year. The median EUI for multifamily buildings in New York City is 132.1. Score a 109 or lower and you earn an A; higher than 160 is a D. But in practical terms, how well do these grades translate to real-life energy use?

No condominium or cooperative board wants to restrict its residents' ability to work with brokers they choose; indeed, some argue that this would be illegal restraint of trade. Yet some brokers are problematic, creating needless issues for boards to deal with, from selling apartments at cut-rate prices, lowering all residents' equity, to simply being a pest who bombards residents with unwanted e-mail. So what can a condo or co-op board do?

Installing solar panels on the roof of your co-op or condo isn't the easiest thing to do. The New York City permitting process can be cumbersome, and not all buildings are good candidates. A property must have a large roof in good condition and, above all, gets ample sun: A building with too much shade will not get enough sunlight to generate energy.

Then there are the financials. If a building is structured as a 501(c)(3) nonprofit, it won't benefit from some of the tax incentives. And since most of the financial incentives come in the form of a rebate, a building's owners need to either have enough cash to pay for the project up front or be able to qualify for a loan.

Recent news affecting co-op / condo buyers, sellers, boards and residents. This week, a New York City co-op board that refuses to recognize Hanukkah? That'd be mashugana if it weren't so disturbing. Plus, another high-rise hooker, recovering from superstorm Sandy, a co-op flood wall in Yonkers and city inspectors have become unglued in Co-op City. And for co-op and condo boards that want good lobby art but can't afford it, two boards have creative solutions.

Recent news affecting co-op / condo buyers, sellers, boards and residents. This week, The Beresford, where Jerry Seinfeld lives, goes after a sidewalk hot dog vendor. Hey, don't let the fact that the city and the police both say he's legal — you just keep on fighting the good fight against nitrates! The FHA is relaxing condominium-certification rules, making it easier to get mortgages. And just in time: New York City condo prices are jumping. Meanwhile, for co-op / condo boards, there's a new resource for tree guards, and an old lesson for Law & Order fans: Don't mess with Lt. Van Buren!

The River Arts cooperative in Manhattan's Washington Heights has saved $15,000 a year in electricity costs since installing rooftop solar panels two years ago — an installation  partly funded by government incentives. River Arts financed the $418,000 project with a federal tax credit, a grant from the New York State Energy Research and Development Authority (NYSERDA), and a city property tax abatement. In all, the credits and grants reduced their final bill to $34,560. Initially, the board estimated it would take eight to ten years to pay back the investment. Instead, it took only three.

Nevertheless, River Arts' costs have gone up by 15 percent because of rising property taxes and skyrocketing fuel costs. Property taxes cost the complex $1 million in 2012, up from $300,000 in 2005. In 2015, when the city phases out No. 6 oil, the co-op will have to use a cleaner, but costlier, fuel.

The co-op has taken many steps to lower costs. When it replaced the lighting in the communal areas with energy-efficient fixtures, it took advantage of a $15,000 NYSERDA grant that brought the price down from $51,000 to $36,000. It took the co-op two years to pay.

... more on tax-fairness legislation introduced in Albany; whether no-smoking buildings affects apartment prices; a lobby renovation done right; and The Sheffield pools its resources. And for co-op and condo boards, an expert answer on who's responsible with bathtubs leak.