A side-by-side of a woman in front of Zara and a Cos store.
Business Insider's reporter compared professional clothes from Zara and COS.
  • London retailer COS, which is owned by H&M, has been expanding in the US.
  • Its sustainable, luxury pieces are often ideal for work attire. 
  • I decided to compare COS and Zara's professional clothes.

Like clockwork, a handful of "it girl" retailers capture a generation's attention every few years.