Tillicum Middle School

Project Overview

With Nature at the Heart

Middle school can be a time of intense social growth and preoccupation, where one can lose sight of the broader environment around us. From a deep history of collaboration, the landscape architect and Bellevue School District were able to bring landscape and the natural environment back to the fore, and even inject its ever-increasing value into the core of the school building itself. Working with the architect, the team was able to unlid a portion of the central commons space to create a striking and highly visible oval-shaped courtyard that is just as serene and impactful from within the space as it is viewed from the interior spaces of the building through panoramic windows. An oval-shaped deck space overlooks multiple class-room sized outdoor learning spaces set above exposed rain-gardens used to treat the adjacent building’s run-off. As student’s move from the school building to the athletic fields in any direction, they pass through or adjacent to natural spaces. The landscape at Tillicum MS is not routine backdrop, instead fostering curiosity and consideration through creative biophilic design.


Bellevue, WA


Bellevue School District

Design Partner

NAC Architecture


2023 Washington Association of Landscape Architects Merit Award – Public Ownership


Tillicum Middle School sits in a suburban neighborhood of Bellevue, WA sandwiched between Phantom Lake, its contributing wetlands, and Lake Sammammish. The new school doubled the capacity of the previous school, and the larger audience necessitated a more impactful school design. Owing to Bellevue School District’s commitment to energy efficiency and positive environmental impact, the school supported early concepts that prized biophilic design principles throughout the site.

Working closely with the architect, we created an open oval-shaped courtyard that sits at an important junction between a main stairway and the student commons area, serving as the heart of the entire project. Architecturally, the designers were driven by a desire to organize interior space around the movement of light throughout the day – and nowhere is the movement of light, weather and air more experiential than looking up through the courtyard’s oval opening.

Within the oval courtyard, the designers partitioned the space between flexible hardscape with seating areas and an educational and soothing vegetated space featuring a variety of native and common Northwest plants with custom printed plant identification signage, engraved on stone pavers. Students less inclined to forge headfirst into nature are invited to interact, investigate and learn about plants in a safe and familiar setting of a stepping stone path. A single, gorgeous specimen Japanese maple anchors the space and its presence permeates the Commons area, serving as a subtly changing beacon throughout the seasons.

Owing to a beautiful and informed approach to daylighting and window design, numerous areas of the building are naturally lit by this exterior space and thus the oval courtyard breathes life into the building itself.

A Sense of Place

Early landscape concepts included preservation of mature conifers at the building entrance and generous landscape buffers of existing vegetation hugging the south and east portions of the site. These concepts were able to be carried through to the final design, and were complimented by naturalistic and native plantings throughout the site and especially along road frontage. In this way the school and its landscape sits more casually within its wetland environs and softens more rigid necessities such as tennis courts and athletic fields – reinforcing its sense of place within the Lake Sammamish watershed.

While surrounding wetland hydrology at the perimeter of the site is subtly complimented, the water processes of the building are expressed more explicitly within the main exterior courtyard on the south side of the building. Catwalks and walkways connect two class-room sized learning spaces over a wide raingarden channel, which serves to treat the two largest wings of the building’s rain water runoff. The entire space is overlooked by a rounded decking and railing that extends the oval-shaped stair lobby directly to the outdoors, beckoning students outside with the repetition of shape. We wanted to highlight the relationship between the building’s infrastructure and natural stormwater processes along a highly trafficked route connecting the school to its athletic fields.

Biophilic design strategies drove the design of Tillicum Middle School. Whenever possible, we wanted students to pass through natural spaces, witnessing and questioning natural processes and hopefully stopping for a while.

Where the site held significant grade change between the building floor elevation and the baseball/softball field, we provided a vegetated slope through which an accessible walkway switchbacks down to the lower grade. While an adjacent stair is provided, we created a more appealing route through rich grass plantings and sumac which serve to accent the building and quickly colonize sloped soils. In this direction, one can access trail connections we designed adjacent to the lower athletic fields so that students and staff could take advantage of the regional Lake to Lake trail system, a valuable existing asset.

Teachers benefit from biophilic design as well! The numerous stresses educators experience are too often overlooked and neglected. The roof of the school’s entrance features vegetated green roof on a private teacher’s roof deck. Here, teachers can experience a quite moment outdoors and recharge between classes or after a challenging conversation with a student. The green roof situated adjacent to the teacher’s seating areas provides calming effects as well as functional stormwater treatment.

Within some leftover open space, we designed a small park-like arboretum of unique tree species within the student drop-off loop. As we know, stacks of cars driven by hurried parents can create stressful situation, and we sought to leverage this otherwise unused space as another opportunity to peak students’ curiosity in the natural world. At the school entrance, we preserved two mature Cedar trees within an oval planter – continuing a design language that will show up within the building’s interior.

With generous rain gardens, educational courtyards and two covered outdoor classroom spaces, a native-focused plant palette and even a small “Arboretum” of unusual trees, Tillicum Middle School has purposeful landscape around every corner, intending to foster relationships with nature and imbue a potentially stressful setting with a biophilic sense of calm. For middle school students, this approach reminds them the natural environment is engaging and beneficial. For students, educators, staff and parents, nature and outdoor learning is at the heart of Tillicum’s middle school experience.