<p>Though it addresses roofs specifically and not walls, that Bloomberg article seems to address the general cost tendency, heating vs.cooling in NYC area.</p>
<p>"Scientists acknowledge that the extra heating costs may outweigh the air-conditioning savings in cities like Detroit or Minneapolis. </p>
<p>But for most types of construction, they say, light roofs yield significant net benefits as far north as New York or Chicago. Although those cities have cold winters, they are heat islands in the summer, with hundreds of thousands of square feet of roof surface absorbing energy. "</p>
<p>FWIW we have newly-insulated attic with light gray shingles, south facing house which gets lots of sun, no trees in front, stucco walls with some insulation who knows how much, replacement vinyl windows. All these features matter, but the only thing up for change any time soon is the paint.</p>