Last week, as spring's balmy temperatures took a temporary dip into glacier territory, the two founding partners of architecture and urbanism firm Weiss/Manfredi led a hard hat tour of their new visitors center at the Brooklyn Botanic Garden (opening in a mere six weeks!). Luckily, magnolias and cherry trees were already in bloom and a bright sun illuminated the mostly-transparent structure. The deceptively modest structure is nestled into a hill on the northeast corner of the site, so 50 percent of its envelope benefits from thermal efficiency. And like any ground-up civil structure worth its salt, it's sustainable, with a geoexchange system comprised of 28 heating and cooling wells, radiant floor heating, and landscaping made of postconsumer recycled building materials. And did we mention it's a looker? Click through for a preview.