Skyscraper Curtain Wall ReplacementPhoto credit: AP Photo/Alan WelnerWhen Philippe Petit walked a high wire strung between the World Trade Center towers, the world was amazed by his grace and daring as he walked on air nearly a quarter-mile above the ground. Today a different kind of dare-devil can be seen hovering above the sidewalk: the crane operators and construction crews that replace curtain walls on skyscrapers in New York.A curtain wall system is an outer covering of a building in which the outer walls are non-structural, but merely keep the weather out and the occupants in. Typical curtain wall infills include stone veneer, metal panels, louvres, and glass windows.Several critical environmental and structural challenges come into play when replacing elements on skyscrapers. Wind is the primary natural force that affects both the structural specifics of the materials and the challenges that come with replacing curtain walls. While replacing windows, wind pressures can make the interior uncomfortable and noisy while the work is ongoing, and even dangerous for the construction crews performing the work. Glass elements must be designed with both wind and load limits in mind, and are often laminated and tempered as a result.Unusual shapes in buildings also cause areas of stress and increased pressure in the materials that must be taken into account when finding structurally appropriate replacements. The shape of the building can also create a wind tunnel, channeling outside air in dangerous ways along the building exterior. The taller the building, the greater the wind pressures affecting both the performance of the building materials and the safety of workers.To compete with increased natural forces at great heights, modern construction crews must have the reflexes of a trapeze performer while they skillfully work high above the city streets. Contact Scott Henson Architect for more information on curtain wall replacement for your building.Read more...
Working with Historic Preservation Societies on Building Restoration
Historic preservation societies are the advocates, guardians, and staunch defenders of the historic built environment. They keep long-standing buildings and neighborhoods safe through advocacy for landmark designation and zoning changes that monitor and regulate new development. These organizations provide not only leadership and education, but resources, support, and expertise to the architects and builders who preserve historic structures for the next generation to use and enjoy.
These societies often provide source material such as photo archives, blueprints, and historical records that are critical to developing a restoration project that is true to the spirit of the original while incorporating changes that modern living demands. The rigorous work of balancing the desires of owners, developers, and the community with the goals of historic preservation societies is a feat that requires a unique architectural disposition and a specialized skill set.
In New York City, the NYC Landmarks Preservation Commission is the government body that designates buildings or neighborhoods as historic, culturally significant, or part of the heritage of New York City that need preservation and protection. The Commission also approves all requests for renovation, repair, or retrofit of such structures.
Privately operated preservation and historical societies work with the NYC Landmarks Preservation Commission to provide expertise, and, in many cases, advocate for historically significant buildings through the lengthy and detailed process of landmark designation. Private societies also manage and administer funding for restoration and repair work through a system of loans and grants. Through their work, these societies directly impact community revitalization and the economic health of their neighborhoods.
The Greenwich Village Society for Historical Preservation , for example, not only works directly on the designation and restoration of historic buildings in i neighborhood, but is also active in the community’s economic development. It supports small business and retail diversity and offers a number of educational and outreach programs.
The following references are links to some of NYC's historical preservation groups.
For more information on New York City building restoration, please contact us.Read more...