For a building to be considered historic, it must:
- Be at least 50 years old
- Have been researched, including documentation of construction date, architectural style and notable features, and important persons or events associated with the property
- Be evaluated for significance to local, state or national history, architecture, and/or culture
- Demonstrate significance in terms of one or more of the National Register’s criteria
Once a building is designated as “historic,” it should be carefully cared for. But general wear and tear is common and expected in historic buildings and will eventually create the need for rehabilitation or renovation, including windows.
When planning a renovation of a historic building, you must do your research to ensure you follow the rules and regulations to which historic properties are subject. And while you want to keep the overall aesthetic of the building, you must ensure the materials and renovations are durable enough to last.
Here are a few factors to consider and keep in mind when replacing windows in historic buildings.
Historic Building Renovation Rules and Regulations
If a building is listed on the United States National Register of Historic Places, renovations will be subject to specific rules and regulations outlined in The Secretary of the Interior’s Standards for Rehabilitation.
These standards are administered by the National Parks Service (NPS) to help assist long-term preservation of the property’s significance. Before you can replace any windows, you must first appear before the review panel that administers the district where the property is located and make the case for the renovations.
Secretary’s Standards for Rehabilitation
In this case, rehabilitation is defined as:
“The process of returning a property to a state of utility, through repair or alteration, which makes possible an efficient contemporary use while preserving those portions and features of the property which are significant to its historic, architectural, and cultural values.”
The standards help determine whether a rehab qualifies as a Certified Rehabilitation and to assist the long-term preservation of a property’s significance through preserving historic materials and features.
There are 10 standards that must be met. For a full list, visit the National Parks Service website.
When presenting your case for renovation approval to the historic committee, there are a few documents you should provide to help the process, including:
- Drawings of the building and proposed renovations
- Depictions including material, operation, installation, and other necessary information
The more prepared you can be, the more likely your rehab will get approved.
Tips for Replacing Historic Windows
Two key factors for replacing windows are:
- Location of the window and elevation of the building/space
- Visibility of window features and details
When historic windows exist, they should be repaired to avoid further deterioration. However, there are several elements to consider when evaluating the match of a replacement window, such as:
- The unit placement in relation to the wall
- The window frame size and shape
- Glass size and divisions
- Sash elements width and depth
- Materials and finish
- Glass characteristics
Overall, the match of a replacement window primarily relies on its visual qualities, such as dimensions, profiles, finish, and placement. The way a historic window operates is also an important factor, but the replacement window does not need to operate in the same manner (or at all). However, the form and appearance cannot be changed to the point that they don’t match the original historic window.
Taking into account the building’s features and window’s visibility, consider the following guidance:
- Replacement windows on primary, street-facing, or other highly visible elevations:
- Must match the historic windows in all their detail and material
- Must match the historic window in size, design, and details that can be perceived from ground level
- Replacement windows on secondary elevations:
- Must match in size, configuration, and general characteristics
- Replacement windows whose interior components are significant to the interior finishes:
- Must have interior profiles and finishes that are compatible with the surrounding historic materials
Aeroseal Windows & Storefront has extensive experience working on historical properties in cities across the country and can help you get the most cost-effective products approved and installed in a timely manner. We take into consideration many factors and work with local, state, and federal agencies to receive historic approval.
Our custom installations will meet your expectations and the requirements of your prehistoric building. For more information or a free consultation, call 1-888-659-8415 or fill out our contact us form online.