Green roofs on hospitals are more common than you might think. Have you designed a green roof? Has your facility installed one?

The benefits may include improved patient, visitor, and staff experience; energy savings; increased roof life; reduced noise levels; mitigation of urban heat island effect; and rainwater management.

A green roof could be included in a new construction project, or it could be a retrofit of an existing roof area. In either case, the very beginning of your visioning process should start with the end users.

Will people be allowed access to the area, or is it just to be seen and not stepped on? If the former, will it be for the general public? Patients only? Staff only? With shorter patient stays these days, patients may take advantage of views to the roof far more than they take strolls across it. Accordingly, we’ve found that it’s often the staff who use these gardens the most, since they’re on-site day after day.

This leads to the idea of seating typologies; consider options for seating large groups, small groups, and solo users so that people have a choice in how they enjoy the space.

Conversely, if you have a situation with longer-stay rehabilitation patients, or even outpatient physical therapy, a green roof designed with some therapeutic features may be in order. The space should be immediately accessible to the patient area it’s serving.

We’ve found that you can design a green roof that’s not obviously a therapeutic garden but still serves the purpose. Water features, planting beds, and benches might be a little higher, though, to make them easier to touch or to sit on. Different types of ground surface materials and level changes can be used to the advantage of those who are working on their walking and gait.

After determining what users the green roof will serve, consider next the structural requirements. In retrofitting an existing roof, unless you want to consider reinforcing it, you must work with the given structural capabilities. Perhaps you can’t support trees, but you can create shade using other means, such as umbrellas.

Two of the photographs included in the image gallery illustrate how an existing roof area was transformed into a much more inviting green roof within the existing structural parameters and with a relatively small budget.

There’s much more flexibility in designing a green roof for a new building, since the structure can be designed to suit. Yet, there are design considerations in laying out the plan that can mitigate an increase in structural support. For example, in a recent project, tree boxes were placed on the structural column grid, rather than randomly in the structural bays.

Additionally, you may want to create paths that “meander,” since walking in a straight line over a distance can create a cadence that could deflect the structural system.

There’s much more that could be said about options for green roofs, and technical considerations for building them. But the main point is, think seriously about adding one. The benefits are considerable.

Joan Suchomel, AIA, ACHA, EDAC, is president of the AIA Academy of Architecture for Health. She can be reached at