ATLANTA—Cortland Partners has adopted the approach of “in-sourcing” key functions—like designing and manufacturing its own building components—for improved tenant satisfaction and investor returns. It's working.

Since 2009, Cortland has expanded its portfolio from 6,000 apartment units nationwide to 40,000 units and a staff of 1,400—not an easy feat considering the state of the multifamily housing market after the Great Recession. The growth is reflected in the National Multifamily Housing Council's 2017 rankings, which place Cortland at number 21 among all apartment owners for most units and No. 32 among community managers.

At the heart of Cortland's success is adopting this vertically-integrated approach. That's a fancy way of saying that they cut out the middlemen to control for quality and costs, while creating their own innovative tools and services not found anywhere else.