Portland City Hall Ecoroof
The program for Portland’s Historic City Hall was to locate 4 different ecoroof types on 5 different roofs while respecting the buildings historic structural integrity. Moreover, the project needed to address specific security issues, lack of access to water for irrigation, and potential difficulty in performing routine maintenance on the ecoroofs.
The main roof has 48 rolling green roof sections that can be arranged in a variety of ways, creating a changing mosaic of rooftop habitat. Other roofs have a modern twist on the beaux-arts style of the building; a 3-d checkered pattern edged in stainless steel.
C-N-C metal crests and garlands provide shade structure, while clipped ‘parterre’ hedges are created by freestanding livingwalls. Additional ecoroof testing areas are also integrated into the main roof.
All of the ecoroofs are designed and planted with a clear intent for seasonal change and adaptation, including their ability to be lifted off the historic building and relocated to other projects nearby.