NEIGHBORS Aritzia, Balthazar, Club Monaco, Free People, Joe and the Juice, Michael Kors, Nike (coming soon), Paper Source, Mark Jacobs. The downtown clothing fashion house founded by Mr. Jacobs spent heavily renovating a ninth-floor showroom at its 72 Spring St. headquarters building to that it reflects a kind of calm, chic modernism that screams new wealth. The design for the space, which was completed last year and will see hundreds of visitors during next month's winter Fashion Week activities, signifies a turning point the brand.