Clune enlisted specialty-glazing contractor
Harmon to handle the field work and endure the closest scrutiny.
According to Harmon, the facade consists of more than 800
steel stops held in place by more than 6,250 screws, and each
screw was countersunk to protect the ever-so-slightly beveled
profile. Tenuta marvels at the scrutiny. They had to be submitted
for approval, were rejected, remade, and resubmitted. Even
the depth of the countersink was debated, until a tolerance
of a mere 1¼64 inch was agreed upon.
The 120 lower lites were replaced with
a clear tempered glass from Viracon, and the inner face was
sandblasted to recreate the exact same effect as the original.
The Miesian scholars were in agreement with this solution.
However, Sexton knew that unless the sandblasted side was
treated, the school would face the same staining and scratching
problems it did before. Fortunately, technology eliminated
many concerns. Computer-controlled manufacturing allows glass
to be both tempered and sandblasted, and as proved here, to
be protected by the application of three layers of ultra-clear
epoxy, which has no reflectivity, will not change character,
and will never yellow.
|S.R. Crown Hall is
returned to its original glory. Krueck &
Sexton Architects and Clune Construction searched
until they found a manufacturer to recreate
the Miesian black that delineates
the structures exoskeleton in stark
contrast to the rest of the campus.
Finally, there was the issue of the paint.
The sharp Mies black had faded to a dull gray.
The original paint could not be used again, because it was
lead-based. Product research led the architects to Tnemec,
an industrial paint and coatings manufacturer known for products
of extreme durability. The three coats that were applied should
last about 25 years.
Studying Krueck & Sextons restoration
and renovation of Crown Hall reveals more about Miess
design methodology than a slide-show lecture in architecture
school ever could. Its work also makes a convincing argument
for balancing preservation of original intent with current
needs. The great Modernist buildings of the 20th century were
meant to have long, working lives. Modifications to Crown
Hall will be necessary again in another 50 years. As evidenced
by SOMs restoration of Lever House in New York in 2002
and Polshek and Partners careful restoration of Louis
Kahns Yale Art Gallery in New Haven, currently under
way, intimate intervention of Modernist icons might be the
only authentic way to know them.