The Resurgence of Vault Lights

Have you ever wondered what those little glass insertions in sidewalks of major metropolitan cities were? In many cases, those glass pieces were flush with the sidewalk or sometimes seemed like slightly raised glass “bumps.” In either situation, those were inserted into the pavement to permit sunlight into spaces beneath the sidewalks. As a re-emerging historic American architectural feature, those original vault lights are being restored and reinvented to serve their original purpose of letting natural light to penetrate into otherwise dark spaces.

Other names for vault lights are sidewalk prisms or pavement lights (UK).

Vault Lights: The Beginning

Invented in 1845 by Thaddeus Hyatt, vault lights were initially used on ship decks to provide light below without using hazardous open flame-producing instruments. These durable glass features were later mounted in cast iron panels and installed in city sidewalks to admit light into basements and spaces below. Before the widespread availability of electric lighting, dead areas and rooms under sidewalks and other overhead structures could then become usable as storage or even apartments with the installation of vault lighting.

The original vault light glass design incorporated a prism shape on the bottom to diffuse and spread the maximum amount of light through a broader area. In some cases, multiple prisms set at different angles would be incorporated to spread the light evenly throughout an even larger room.

In addition to those early underground rooms and spaces, original subway stations benefitted from the light admitted by early vault lights.

Vault lights were popular in cities throughout the country from 1860 through the 1930s. While some vault lights remain in New York and other cities, many of us still recall walking over these unique circular glass sidewalk features, perhaps without ever knowing their purpose. However, many of these vault light systems deteriorated and created hazards with broken seals and glass that could make walking more hazardous. Broken vault lights and seals also allow water to penetrate the surface to damage the spaces below. As a result, many have been covered, removed, or filled in with concrete for a quick fix.

An Early Solution to Sustainability

While the primary purpose of vault lights was to illuminate space that could not admit natural lighting, the introduction of these was a likely an unconscious effort toward sustainability and the preservation of energy. Although electricity was not yet available in the mid-nineteenth century, building owners were able to light spaces while preserving the characteristic lighting fuels like gas, oils, and candles. Also, still in line with sustainable activity, the air within those enclosed spaces would be decidedly better without the smoke producing light sources of old.

Even as electric lighting became common, vault lighting continued to provide illumination during the day.

Vault Light Restoration

Many city leaders and historic preservation groups have recognized both the historical, as well as the aesthetic value of vault lights.

Since many vault lights panels have lasted for more than a century, these cityscape artifacts have become prized historical treasures. Those lenses that have survived are often damaged and discolored from years of use. Historic preservation groups are striving to renovate or replace these old vault lights to reflect their original purpose. With modern glass technology, replacement and repair are possible, perhaps not as severe as we may first imagine.

The practical motivation for replacing or repairing vault light remains the same as a century ago. New or rebuilt vault lighting lenses will still admit much needed natural light into dark spaces and accomplish this without consuming the energy required for artificial lighting.

Today’s vault or pavement lights can be precast or even cast in place in concrete or steel frames. The lenses will be created from solid glass or load-bearing sealed hollow glass pieces that can be designed to diffuse admitted light in virtually any direction. Shapes may be circular, square, triangular, or even irregular to accommodate various designs.

Vault Lights Have Inspired Daylighting in Buildings and Homes

Modern glass block and brick are experiencing a resurgence in the construction industry. The same durable, weight-bearing glass concepts are being applied beautifully in homes and businesses. Using glass block for stairs, walls, floors, and ceilings, owners can spread natural and artificial light throughout the structure and provide light to interior rooms, basements, and otherwise confined spaces.

In fact, on the grander scale, whole building exteriors are being beautifully clad with insulated glass block to create award-winning effects and to provide a spacious well-lighted interior.

GBA Architectural Products + Services, The Glass Experts

GBA Architectural Products + Services represents many of the world’s most important architectural glass manufacturers. Suppliers of structural glass, glass block, and LightWise glass systems, GBA is also an active component of vault light restoration throughout North America. The professionals at GBA are prepared to collaborate with restoring these essential historical features and can duplicate original designs with the best, most durable, and highly functional vault glass panels.

Today’s glass block designs and choices from GBA Architectural Products + Services are durable enough for any purpose and can add light and beauty to any project.

Visit the GBA Architectural Products + Services website to learn more about the favorable contribution glass products are making to the world of architecture. Request product information on the GBA website by filling out the online form.

Contact GBA Architectural Products + Services for more information about glass architectural products. GBA Offices are regionally situated in the eastern, midwestern, and western regions of the United States.

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