Reviving
a Living, Breathing Building
Adaptive Reuse of the Sears Warehouse/Store into the Midtown Exchange
by Terry Olsen
Buildings are living, breathing bodies that react with time as
well as the elements. (Don’t we all?!) Converting the Sears
buildings into new beings posed challenges for the team of Mike
Ernst, Ryan Companies, Craig Milkert, CDG, and John Russo, CC&I.
In 1928 Sears built a neighborhood landmark warehouse/office building
on the corner of Lake Street and Chicago in southeast Minneapolis.
What is currently the Midtown Greenway was at that point part
of the rail line that provided a distribution network to supply
the warehouse. In 1964 an addition was built spanning the greenway,
and in 1979 another expansion occurred to the north. But then
the life of the building went out of it. In the 1990’s Sears
relocated its distribution network to warehouses in the suburbs.
By 1994 the retail portion was closed and the building sat vacant
for many years. The challenge of reuse of this landmark was critically
important for an ethnically diverse neighborhood with low-income
families and few transportation options.
How is a building a living, breathing beast and can you train
it to react differently? Look at the skeleton, circulation, and
skin of the building - changing any one component can have implications
on the mere survival of the beast, not to mention its neighborhood.
The structural backbone of the beast was a column grid of 20’
x 20’, which posed challenges for reuse options (for instance,
consider the optimal way to arrange the maximum number of 8’
x 8’ cubicles). The floor plates were massive, with 240’
in the minimum dimension. This meant that natural light did not
reach the inner bowels of the beast, but this was acceptable for
warehousing at that time. With the desire to transform segments
of the existing structure into a hotel and condominiums, portions
of floor plate s
labs were removed to create an atrium and a light
well. The column structure elements stayed, however, with the
caps remaining to reflect what was historically there and to identify
where the guts were removed. Techniques included x-raying the
slabs with ground-penetrating radar to identify the location of
rebar to assist in surgically removing sections of the building.
Circulation patterns required modification, particularly in the
heart of the building. Twenty new elevators were installed, since
existing freight elevators were the wrong size and existing passenger
elevators were in the wrong location. Fun fact: Original circulation
of product had an interesting story. One historical find was the
spiral slide: warehouse workers on roller-skates picked mail-order
products off the shelf and slid them down the spiral slide to
shipping for distribution to their final destinations. Uncovering
these product supply and delivery methods was exciting, but ultimately
not reusable and so this form of circulation was removed.
Eyes are the windows to the soul. But windows are the eyes of
the building. With over 825 openings, existing corroded steel
windows were replaced, restored, and added for a bright-eyed future.
Operable windows were included in the condos, while fixed units
were utilized throughout the office and retail spaces.
When considering how to reuse a building most effectively, exterior
skin has a significant impact on the life of the building. The
existing building walls, comprised of brick 3 to 5 wythes thick
without insulation or flashing, were built at a time when brick,
labor, and especially energy were cheap. Now, in 2006, energy
is a larger concern so the consideration of adding insulation
was investigated. Over time the moving, breathing building has
matured - with cracks in its skin and movement in its joints.
Moisture vapor breathed in and out of the skin, converse to what
current technology teaches us to prevent. Parged parapets spalled,
corroded relief angles needed some relief, anchors were rusted
away, and extensive testing combined with thoughtful contemplation
based upon years of wisdom, led to considerations of how to change
the skin. Originally this beast was only heated, and concerns
of condensation, efflorescence, and peeling paint posed risks
that questioned how the living, breathing building would respond
to insulation, vapor retarders, air barriers, and sealing of the
brick when air conditioned. Ultimately, the diagnosis was that
the existing wall system, with an R-value of only 1 or 2, functioned
as a barrier wall system rather than a cavity wall system with
a drainage plane, and the current skin worked best to keep the
water out. Radiant heat was added to the building to offset heat
loss, with the realization that the majority of the exterior spaces
have large expanses of windows, and heat loss would be an issue
whether or not insulation was added to the building skin.
So how did this revived beast do? Comparison-shopping to a nearly
identical building Sears built in Boston at about the same time,
and that was also recently renovated, the Boston “twin”
took 18 months for construction of the shell and only had a couple
tenants open at that point. The Midtown Exchange took 15 months
to open the hotel, Allina’s new office space, and the housing
component. With the Global Market opening a little later with
start-up businesses and the revitalization of a neighborhood,
the partners are proud of training this beast into a gentle giant.
October Meeting Photos
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