Reading Hospital’s 46-acre campus in West Reading, Pa., has seen significant change during its 100 years. The site has expanded via a collection of additions, new entrances, infills, and overbuilds.

Through this, the surgical services grew across five buildings in a fractured arrangement that wasn’t conducive to optimal patient care.

In 2011, the hospital engaged Ballinger (Philadelphia) to conceptualize options to consolidate the campus’ surgical services. In August 2013, construction began on the Reading HealthPlex for Advanced Surgical & Patient Care, with the 476,000-square-foot surgical and inpatient tower opening in March 2017.

The hospital administration utilized the last available piece of land on campus for the new eight-story building—an area notable for a 30-foot slope. This dramatic grade change provided the opportunity to situate a significant portion of the 115,000 gross square feet of surgical program requirements below grade.

This satisfied the clinical need to collocate surgical services, including 24 operating rooms, on a single level to provide more efficient patient and staff flows. It also created the opportunity for a dedicated entrance to the new surgery center. A five-story bed tower, with 150 new private patient beds, was placed atop the surgical platform, with a smaller footprint than the base below.

Prioritizing healing views for patients

However, in early designs, this approach didn’t offer the same healing views that patients were accustomed to in Reading Hospital’s 500 existing patient rooms. The campus includes airy courtyards nestled between brick and limestone buildings, whereas concepts for the addition left large portions of the new surgical platform and its simple stone ballast roof exposed.

Taking note of the neighboring Wyomissing Park, home to an art museum and walking trails, designers saw an opportunity to utilize the HealthPlex’s sloping site and cover the surgical platform with an 88,000-square-foot vegetated green roof—the third-largest green roof on a healthcare building in the United States.

The new patient rooms would then have views of the serene healing garden. Patients and families moving throughout the building could also experience access to natural light and garden spaces, such as a tranquil fountain area, a pergola offering shade in the summer, an oval-shaped grassy area anchoring the rooftop garden, and a strolling meadow walk that connects to Wyomissing Park.

Skylights and light wells would also allow natural light to enter the prep and recovery platform below the green roof.

Digging in to green roof design

Although the idea presented many benefits, the owner wouldn’t sign off on the green roof until designers addressed some challenges that came with it, especially in light of its location above clinical areas.

One directive was that the garden be easy to maintain and not require additional staff. The roof is planted over a waterproofing membrane to prevent leaks and has an automated irrigation system, which reduces maintenance.

A typical failure point in green roof implementation is when drains become clogged with vegetation and debris, so the team implemented a continuous drainage layer and sloped the roofing membranes toward the drains to prevent water backup and flooding.

Additionally, all drains can be visually inspected via access chambers, which are 3 feet deep and nestled within the plantings, so that maintenance staff can easily ensure that the drain pathways are clear.

Another issue was the weight of the plantings; full-size trees require 4 feet of earth for the long-term health and growth of the plants.

When the structural team ran the calculations for the initial design, the estimated weight for the soil alone was roughly 16,000 tons, which translates to 500 pounds per square foot. This estimate didn’t include the weight of the trees themselves or the planned pergola and fountain.

In order to achieve the full range of vegetation, from small flowers to full-size trees, the design team adjusted its plans to include a mix of soil and extruded polystyrene to reduce the weight.

Trees were strategically placed in areas above structural columns and/or additional steel framing for added support. In areas with smaller plantings, layers of lightweight polystyrene were used to create the base and shaped earthen forms, which were then covered in layers of roofing membrane and limited soil for the shallow plantings.

By locating the trees first, the deeper, heavier soil layers were better controlled, and then the thinner planting layers were woven together to create a lush landscape without adding unnecessary weight. With these changes, the weight of the final design was reduced by 30 percent.

Another adjustment to the initial design was replacing sand between paver joints on the pathways with a larger aggregate material to allow better flow of water through the material layers as part of the stormwater management strategy.

The rooftop garden plan also had to account for sun and wind exposure, which can create pockets of plantings that need additional water. Extra irrigation was added in areas that receive southern exposure and dry out more easily.

To address wind exposure, a paver grid, edge stones, and geomats (a type of erosion-control mattress made from polypropylene and high-density polyethylene) were installed to reinforce the soil during vegetation growth and reduce erosion.

Benefits of rooftop gardens

Considering the increasing challenge of stormwater management in urban areas, the large scale of plantings on the HealthPlex helps reduce heat island effect. It also aids in capturing and slowing storm water during heavy rains, reducing the threat of sewer overflows, and returning cleaner water to the surrounding watershed.

Additionally, the hospital garden delivers a social return on investment by creating an accessible public space in the community. The running paths in the nearby park lead up the stairs to the garden, bringing visitors to the site who may have no direct connection to the surgical platform below.

Staff are encouraged to take breaks in the shade of the garden, and patients are frequently seen outside experiencing nature just steps away from their rooms.

Staff report that two features—the fountain with its tranquil sounds, and the large grassy area surrounded by benches and paved walkways—have been popular attractions since the garden opened.

On the operations side, maintenance issues have proved manageable for the staff. Additionally, a local company was contracted to handle weeding and maintenance on a scheduled timeframe, ensuring the space stays well kept for years to come.

Louis Meilink Jr., AIA, ACHA, ACHE, is principal at Ballinger (Philadelphia). He can be reached at Christina Grimes, AIA, LEED AP BD+C, EDAC, is associate principal at Ballinger. She can be reached at