Although metal windows were available as early as 1860 from catalogues
published by architectural supply firms, they did not become popular
until after 1890. Two factors combined to account for the shift
from wooden to metal windows about that time. Technology borrowed
from the rolling industry permitted the mass production of rolled
steel windows. This technology made metal windows cost competitive
with conventional wooden windows. In addition, a series of devastating
urban fires in Boston, Baltimore, Philadelphia, and San Francisco
led to the enactment of strict fire codes for industrial and multi-story
commercial and office buildings.
As in the process of making rails for railroads, rolled steel
windows were made by passing hot bars of steel through progressively
smaller, shaped rollers until the appropriate angled configuration
was achieved. The rolled steel sections, generally
1/8" thick and 1" - 1-1/2" wide, were used for
all the components of the windows: sash, frame, and subframe. With the addition of wire glass, a fire-resistant window
resulted. These rolled steel windows are almost exclusively found
in masonry or concrete buildings.
A by-product of the fire-resistant window was the strong metal frame
that permitted the installation of larger windows and windows
in series. The ability to have expansive amounts of glass and
increased ventilation dramatically changed the designs of late
19th and early 20th century industrial and commercial buildings.
The newly available, reasonably priced steel windows soon became
popular for more than just their fire-resistant qualities. They
were standardized, extremely durable, and easily transported.
These qualities led to the use of steel windows in every type
of construction, from simple industrial and institutional buildings
to luxury commercial and apartment buildings. Casement, double-hung,
pivot, projecting, austral, and continuous windows differed in
operating and ventilating capacities. In addition,
the thin profiles of metal windows contributed to the streamlined
appearance of the Art Deco, Art Moderne, and International Styles,
among others.
Historic metal windows provide abundant natural light in this rehabilitated industrial space. Photo: NPS files. |
The extensive use of rolled steel metal windows continued until
after World War II when cheaper, noncorroding aluminum windows
became increasingly popular. While aluminum windows dominate the
market today, steel windows are still fabricated. Should replacement
of original windows become necessary, replacement windows may
be available from the manufacturers of some of the earliest steel
windows. Before an informed decision can be made whether to repair
or replace metal windows, however, the significance of the windows
must be determined and their physical condition assessed.
"The Repair and Thermal Upgrading of Historic Steel Windows" an Historic Preservation Brief
