Some of the
greatest restoration challenges arise when historically significant works
weather, degrade, are neglected, or simply have suffered through inappropriate
renovations. Restoration strategies are compounded when original historic materials,
either natural materials like wood or stone, or production processes are no
longer available. And when the failure is due to improper design or inadequate
construction methods, corrective restoration methods may alter or compromise
the original design intent. The following three case studies illustrate restoration
philosophies based on balancing preservation, resolving the underlying building
deficiencies, and introducing “thoughtful change” in protecting significant
local structures for future generations.
Case Study 1
John Yeon’s 1948 Portland Visitors Center
was designed as an exhibition showroom with large open spaces, a pinwheel plan,
on a highway dividing median, accessible by car, and constructed of
standardized wood framing components including recently developed experimental
plywood. When the highway was replaced with a riverfront park and the Visitor Center
programming was relocated, the singular purpose building became obsolete resulting
in a number of incompatible conversions including substantial alteration of the
main gallery space to an industrial kitchen. Contributing to the slow demise
was the degradation of the exterior wood components and failure of the plywood
as a result of the northwest climate and inadequate weather protection. By the
time the Friends of John Yeon and the City of Portland Water Bureau invested
resources into the restoration, the Visitor Center had lost or compromised 80%
of its historic interior finishes and the exterior façade had been heavily
altered. However, the original floor plan, massing, scale, exterior spaces, and
essence of Yeon’s modular design and sense of place remained.
The restoration approach focused on preserving these significant design
elements while providing flexibility of interior layout.
Space
programming respected the historic floor plan and scale of the original
structure and recreated Yeon’s original design intent of integrating indoor space
with outdoor space. Extraneous equipment and unsympathetic additions were
removed from both the interior and exterior. Interior design elements,
furniture, and fixtures maintain the open gallery spacial quality while
integrating new furniture and fixtures meeting the needs of the tenant. Major
preservation focused on the exterior restoring original paint colors through
serration studies, restoring building signage in original type style and
design, preserving original wood windows, when present, and restoring the
intimate courtyard with a restored operating water feature.
Case Study 2
Moore,
Lyndon, Turnbull & Whitaker’s 1965 Pavilion
at Lawrence Halprin’s Lovejoy Fountain is a whimsical all wood structure with a
copper shingle roof. Although a small structure, the pavilion represents a major
mid-transitional work for Charles Moore as his design style moved from mid-century
modern to Post-modern design. In keeping with the naturalistic design aesthetic
established by Halprin, northwest wood species comprise the major structural
system including the roof trusses, vertical post supports, and vertical cribs
built from 2 x 4 members laid on their side and stacked.
Vertical
loads are transferred from the trusses to the wood posts and spread to the wood
cribs. Under the point loading, the cribs have compressed resulting in a sag or
lean in the roof structure. Since the 2 x 4 wood members have crushed, they
cannot be restored or salvaged as part of the restoration effort so new members
were designed to replace the historic material.
The restoration
approach is intended to correct the structural deficiencies and replace the
failed members with no changes to the historic appearance of the structure. The
crib design allows for insertion of new steel elements, invisible from the
exterior, capable of providing additional support for vertical loads. The
difficulty arises because standard wood products available today have different
visible and strength attributes from standard components available in 1965. Sourcing
appropriate lumber is dependent upon clear and quantifiable specification, high
quality inspection, and visual qualities. There are no structural standards for
reclaimed or
recycled lumber compounding the incorporation of “old growth”
lumber as part of a new structural system. When original source material is no
longer available, best practices for narrowing the selection of new materials
will of necessity be combined with subjective visual qualities and a best-guess
scenario as to how the new material will age in place similarly to the historic
material. There are no single solutions so experience is key.
Case Study 3
Whether or
not Michael Graves’ Portland Building
is considered a master work is greatly debated. Never the less, the building
was nominated to the National Register of Historic Places after only 30 years
and is recognizable around the world as THE building representing the start of
Post Modernism. There is no debate to the fact that the building leaks.
However, the method of building envelope repair could dramatically or minimally
impact the exterior character defining features.
The façade
of the Portland Building incorporates standardized aluminum single unit windows,
aluminum windows ganged together to form a curtain wall, ceramic tile, and
stucco veneer as the prominent construction materials. All of these systems or
individual components are neither produced nor assembled currently in similar
manners due to improvements in technology and building envelope science.
Proposals to
improve envelop performance of both the individual window units and window
systems are challenged in finding products that will both improve performance
and retain the aesthetics of a Post Modern building. (i.e. retain the essence
of criticism towards Post Modernism by preserving the appearance of
insubstantial material installed as a thin veneer). Windows have always been a
source of controversy in preservation and now the definition of windows has
expanded to include curtain wall systems as the importance of preserving Recent
Past and Modernism has entered into the mainstream.
When a
structure, like the Portland Building, relies heavily on the expression of its
skin as the character defining feature, off the shelf solutions for fixing
envelop deficiencies must be expanded to include customization, façade impact
studies, robust strategies for solving the issue, and out-of-the-box thinking
by conservators, architects, historic consultants, and building envelope
experts. A collaborative approach based on the original architect’s design
intent must drive the decision making. It is an unusual approach, but original
design intent will be a key factor when resolving façade problems on Modern and
Post Modern structures.
