A Sustainable Brownstone Transformation in Brooklyn

The street facade of New York City’s first certified Passive House, known as Tighthouse, is clad in pale gray stucco, sculpted with a few historic-looking details. But, if you knock on that wall, it sounds hollow: The stucco is merely the outermost layer in a 20-inch-thick insulated sandwich. The original brick is buried deep inside, where it can do no harm—via chinks, cracks, or settling—to the supersealed box this 19th-century, 3,120-square-foot Park Slope house has now become. The cornice, too, is a lightweight contemporary replacement: a hollow fiberglass shell mimicking a wood original.