Identify, Retain and Preserve
Identifying, retaining, and preserving windows--and
their functional and decorative features--that are important
in defining the overall historic character of the building.
Such features can include frames, sash, muntins, glazing,
sills, heads, hoodmolds, panelled or decorated jambs
and moldings, and interior and exterior shutters and
A condition assessment of the frame supporting
the stained glass window is as important as evaluating
the stained glass itself. Photo: Neal A. Vogel.
Conducting an indepth survey of the condition of
existing windows early in preservation planning so that
repair and upgrading methods and possible replacement
options can be fully explored.
Altering windows or window features which are important
in defining the historic character of the building so
that, as a result, the character is diminished.
Changing the historic appearance of windows by replacing
materials, finishes, or colors which noticeably change
the sash, depth of reveal, and muntin configuration;
the reflectivity and color of the glazing; or the appearance
of the frame.
Obscuring historic window trim with metal or other
Replacing windows solely because of peeling paint,
broken glass, stuck sash, and high air infiltration.
These conditions, in themselves, are no indication that
windows are beyond repair.
Stabilizing deteriorated or damaged windows as a
preliminary measure, when necessary, prior to undertaking
appropriate preservation work.
Failing to stabilize a deteriorated or damaged window
until additional work is undertaken, thus allowing further
damage to occur to the historic building.
Protect and Maintain
Protecting and maintaining the wood and architectural
metals which comprise the window frame, sash, muntins,
and surrounds through appropriate surface treatments
such as cleaning, rust removal, limited paint removal,
and re-application of protective coating systems.
Making windows weathertight by re-caulking and replacing
or installing weatherstripping. These actions also improve
Evaluating the existing condition of materials to
determine whether more than protection and maintenance
are required, i.e. if repairs to windows and window
features will be required.
Failing to provide adequate protection of materials
on a cyclical basis so that deterioration of the window
Retrofitting or replacing windows rather than maintaining
the sash, frame, and glazing.
Failing to undertake adequate measures to assure the
protection of historic windows.
Repairing window frames and sash by patching, piecing-in,
consolidating or otherwise reinforcing them using recognized
preservation methods. The new work should be unobtrusively
dated to guide future research and treatment.
These workmen are performing exterior window
maintenance after the protective glazing--which
had prevented maintenance--was removed. Photo:
Neal A. Vogel.
Failing to protect the historic glazing when repairing
Removing material that could be repaired, using improper
repair techniques, or failing to document the new work.
Failing to reuse serviceable window hardware such as
brass sash lifts and sash locks.
The following work
is highlighted to indicate that it represents
the greatest degree of intervention generally
recommended within the treatment Preservation,
and should only be considered after protection,
stabilization, and repair concerns have been addressed.
Limited Replacement in Kind
Replacing in kind extensively deteriorated
or missing parts of windows when there are surviving
prototypes such as frames, sash, sills, glazing,
and hoodmolds. The new work should match the old
in material, design, color, and texture; and be
unobtrusively dated to guide future research and
Replacing an entire window when limited replacement
of deteriorated and missing parts is appropriate.
Using replacement material that does not match
the historic window; or failing to properly document
the new work.