According to The Real Deal, via the Downtown Alliance, the center of the New York architecture world is heading south, with over 100 architecture and engineering firms concentrated in Lower Manhattan. Nearly half of them moved there in the last decade or so, while others—like SOM and AECOM—settled in the area even earlier.

Apparently, a lot of the firms were once in Midtown South and SoHo, but rising rents forced them out. In fact, 10 of the 15 architecture firms that relocated to Lower Manhattan in 2014 were coming from the former. That’s because, in part, rents jumped a solid 13% each year between 2010 and 2013 in Midtown South—the “most expensive major market in the nation,” according to Tristan Ashby of JLL.

Other forces driving architecture down into the lower reaches of Manhattan include easy access to mass transit as well as an influx of new restaurants.

But it’s not clear how long Lower Manhattan will remain the loci of New York architecture. For example, BIG has announced that they plan to head across the East River to set up shop in Dumbo.