The 17th-floor Washington Mutual Bank
roof garden is a green roof that is also the vital social
space and civic heart of the bank’s downtown campus.
Rather than meet the City of Seattle’s minimum
open space requirements, the garden’s usable area
was enlarged threefold to provide decks and pathways
that showcase views across Elliott Bay while integrating
elements that tell a story about the bank, its local
origins, and the community it serves.
The landscape architect was commissioned
to develop designs for the 17th-floor roof garden at
the new Washington Mutual Bank Tower. The design philosophy
addressed four major principles:
Genus Loci: Landscape
design that references the site in an abstract –
not literal – manner, adds a level of profoundness
to a place. This roof garden offers an opportunity to
interpret a regional ‘sense of place’, and
to offer a narrative of the Bank’s history and
role in the community.
Edges: Inside / Outside:
The adjacency between indoor and outdoor space is crucial.
Strong connections provide places of prospect and refuge,
mediate extremes of climate, and create a social energy
at the edge. The success of the roof terrace is a result
of studying connections through that edge.
Views: Intimate / Grand:
This roof garden is experienced from the greater scale
of views to and from the cityscape, and from the more
personal interaction of those using the space. Attention
was paid to materials and pattern viewed from above
while providing comfort.
Program: Event / Everyday: Our role was to prove that the garden could be an extension
of the work place while also being an formal event space.
The roof deck becomes the physical heart of the building
and social soul of the bank.
Landscape Architect’s Role
The landscape architect for the
project developed design concepts for the roof 17th
floor roof deck in close collaboration with the architect
and project engineers. Curtain walls and seating at
the building edge further connect the garden to the
interior lounge creating a seamless indoor-outdoor experience.
Key collaborative efforts included working with architects,
interior designers, and structural engineers to develop
an outdoor fireplace, boulder outcroppings, and windscreens
into a fully integrated landscape and building design.
As a result the garden has already become
the most vital social and event space for the client’s
central downtown campus. Planting, pathways, and wood
decking were designed to symbolically represent the
diverse landscapes of Washington State. As almost two-thirds
of the deck is planted with predominantly drought-tolerant
and native plants, the 17th floor garden has already
gained the reputation as one of Seattle’s largest
Local / Regional Significance
This project demonstrates landscape architecture’s
contribution to the greening of the urban environment,
particularly in a city that boasts a reputation for
a somewhat subversive roof garden movement. These ‘Secret
Gardens of Seattle’ can be glimpsed throughout
the city especially in the Pioneer Square and Belltown
districts where planting often cascades down building
walls or rises out of roof cloisters. This roof garden
is a nod to a local vernacular while observing the
unique geography, climate, and contrarian spirit of Seattleites
that fostered this reputation.
As this project has already resulted in
the development of another roof garden for a large Seattle
insurance corporation, this garden has actually catalyzed
a friendly competition between corporate citizens for
the best roof garden in a city of roof gardens.
An understated feature of the roof garden
is how it combines usable public space for human enjoyment
with many broader ecological green roof attributes,
including urban heat island effect reduction, stormwater
retention, and native and drought-tolerant planting.
This project demonstrates that sustainable landscape
roof design need not be limited to extensive low-maintenance
green roofs, but that it can also be practical, social,
symbolic, and contemporary.
Two unique features in the garden symbolize
the bank and its history: a glass-beaded abacus screen
wall is a whimsical and interactive version of an ancient
tool of counting, and ‘The Change Garden’
- a repository for spare change that will be donated
to Seattle’s charitable organizations - demonstrate
the Bank’s ongoing role as a leading corporate
Challenges faced during construction of
the project included a short window for installation
of roof elements including boulder placement, screen
and deck installation, and collaboration with interior
finishes. The boulder outcrop was particularly challenging
from a weight and handling perspective. Extensive planning
to select and mockup the boulder composition off-site
resulted in a swift re-assembly on the deck with limited
impact on overall building construction schedules, crane
time, or other adjacent trade work.
Phillips Farevaag Smallenberg
Landscape Architect Project Team:
Chris Phillips, Partner-in-Charge
Joseph Fry, Project Manager
Sandra Moore, Principal, Birmingham Wood
Annabel Vaughn, Birmingham Wood
Rod Turkington, Turkington Associates
David Yuan, Principal
Client: Washington Mutual Bank
General Contractor: Sellen Construction
Landscape Contractor: Teufel Nursery
Stone Mason: Star Masonry
Glass Abacus: Joel Berman Glass
Magnusson Klemencic Associates
Coughlin Porter Lundeen