Morningstar’s employees and visitors enjoy a 3,500 square-foot roof garden shaded by a bosque of honey locust trees, providing a sky-bound escape where repose and recreation are encouraged.

When shopping at Chicago’s Block 37, a downtown hub for retail, dining, and entertainment, one probably isn’t aware of the green roof that hovers seven floors above. The building’s tenant, an investment research firm, wanted a series of elevated outdoor spaces to complete its new Chicago headquarters.

With a non-hierarchical ethos at the core of its practice, it was important to the client that the outdoor spaces be just as inclusive and open as its indoor workspaces, enabling not only free-flowing and democratic dialogue, but program flexibility so any genre of gathering - from coffee breaks to alfresco meetings and parties - could be achieved with ease and comfort. Clustering the trees into a tight central grove optically widens the outer paving into a generous podium, and helps the space achieve this pliancy.

To withstand the harsh conditions that typically challenge rooftop plantings, our team designed with “bullet proof” plant varieties, like honey locusts and hardy euonymus coloratus. Slightly irregular placement of the locust trunks avoids the absolute symmetry of a classic bosque, responding to the garden’s relaxed mood and treating individual growth patterns as aesthetic assets.

The most devious spatial strategy here is the clear glass guardrail that our team installed. An almost invisible barrier, it opens the roof to splendid views of historic landmarks like the Reliance Building and the old Marshall Fields Department Store, creating the sensation that those standing at the edge are floating mid-level above the city.