Seattle Children’s PlayGarden

Location: Seattle

Owner/developer: Seattle Children’s PlayGarden

Project team: Roy E. Dunham Co., general and concrete contractor; Babienko Architects, architect; HSV Engineers, structural engineer; CalPortland, ready-mix supplier

The Seattle Children’s PlayGarden is designed to provide recreational, therapeutic and educational opportunities for children of all ages and developmental levels.

The grounds include the new Garden House, Play Plaza and the recently renovated Shelter Building.

Durable, low-maintenance materials were required to respond to the rigors of indoor-outdoor gardening and programmed youth activities, making concrete a good material choice.

The Garden House is constructed with 12-inch-thick cast-in-place insulated concrete form walls. The ICF walls reduce the building’s heating and cooling needs. During the summer the walls store heat during hot days and release the heat slowly over night. Throughout the winter the ICF walls will maintain interior thermal comfort by storing heat and retaining it within the building as a uniform insulated weather barrier.

Indoor heating is provided in the Garden House from an ultra-efficient indirect boiler that circulates hydronic radiant heat through in-floor radiant tubing, cast directly into the concrete floor. Openings in the ICF walls, in combination with the operable garage doors, provide natural daylight and enhance natural ventilation to improve indoor-air quality.

Five-thousand square feet of impervious surface area was created between the Play Plaza and Garden House. The vegetative roof on the Garden House reduces stormwater runoff, reduces the heat-island effect, insulates the roof and extends the warranty of the membrane roofing system.

Remaining runoff is captured and directed into the bioswale located on the south slope of the PlayGarden. Surface water is then directed into a series of check dams, distributing the water laterally into the hillside.