A Green Solution: Energy-Efficient Architectural Windows for Historic Buildings 

by | May 31, 2023

At T.FIN Building Solutions, we understand architects are constantly looking for ways to make buildings more sustainable and energy efficient. When it comes to retrofitting historic buildings, this can be a particularly challenging task. However, with the right approach and the use of energy-efficient architectural windows, we can achieve significant improvements in a building’s energy performance while also maintaining its historic character.

Let’s explore the benefits of energy-efficient architectural windows for historic buildings and the practical solutions for architects to improve the sustainability of their projects.

Why Retrofitting Historic Buildings with Energy-Efficient Windows Matters 

Historic buildings are an important part of an area’s heritage, but they can be energy-intensive structures. Most historic buildings requiring a retrofit were constructed before modern building codes, and as a result, they often lack the insulation and air sealing required for energy efficiency.

Retrofitting historic buildings with energy-efficient windows can significantly improve their energy performance, reduce greenhouse gas emissions, and lower utility bills. In addition, energy-efficient windows can enhance the comfort and livability of the building by reducing drafts and improving indoor air quality.

Moreover, bringing old unused building stock back to relevant income generating and neighborhood betterment holds immense value. By retrofitting historic buildings with energy-efficient windows, not only can we preserve the unique architectural and historical character of these structures, but we can also revitalize and breathe new life into neglected areas. Repurposing these buildings for income-generating activities such as shops, offices, or community spaces can contribute to local economic development and create job opportunities. Furthermore, the revitalization of historic buildings can have a positive ripple effect on the surrounding neighborhood, inspiring community pride, fostering social connections, and attracting further investment.

Choosing the Right Windows for Historic Buildings 

When retrofitting historic buildings with energy-efficient windows, it is important to choose the right windows to maintain the building’s historic character. Some manufacturers, like T.FIN’s premier partner Peerless Products, Inc., boast a line of windows classified as “historic” especially for these purposes. Regardless of which window product is selected, here are the main factors to consider when updating historic windows:

Window Frame Material 

Historic buildings often have specific window frame materials. When selecting energy-efficient windows, it is important to choose a frame material that matches the original material as closely as possible. This will help maintain the building’s historic charm while improving energy performance.

Importantly, the local historical society can dictate window frame material. For example, the Minnesota Historical Society outlines wood frames as preferred over vinyl or metal material. The experts at T.FIN can help ensure your historic window order is in compliance with the local historical society.

Window Design

Window design is equally important when retrofitting historic buildings. The window design should match the original windows as closely as possible to maintain the building’s historic character. However, the design needs to be updated to allow for the installation of energy-efficient technologies such as insulated glazing or low-e coatings. This can be particularly tricky if a building has earned preservation status through the local historical society, making it important to partner with a product manufacturer capable of custom orders for your unique project.

Preservation Guidelines 

The most historic buildings are often subject to preservation guidelines that dictate what changes can be made to the building’s exterior. It is important to work closely with the preservation board to ensure that the energy-efficient windows meet all the requirements while updating a building’s energy efficiency.

When working with a preservation board, it’s critical to select a window partner with extensive knowledge of guidelines and a robust project portfolio that showcases updated window products in historic buildings.  

Energy-Efficient Window Technologies 

There are several energy-efficient window technologies available that can be used to retrofit historic buildings. These technologies include:

Low-E Coatings.

Low-E coatings are thin, transparent layers of metal or metal oxide that are applied to the surface of the glass. They reflect heat back into the building during the winter months, keeping the building warm and reducing heating costs. During the summer months, they reflect solar radiation away from the building, keeping it cool and reducing air conditioning costs.


Insulated Glazing.

Insulated glazing consists of two or more panes of glass separated by an air or gas-filled space. This creates a barrier that reduces the transfer of heat and cold between the interior and exterior of the building. Insulated glazing can significantly improve the energy performance of a building by reducing heating and cooling costs.

Most modern windows feature some variation of insulated glazing to meet the stringent quality standards outlined in today’s building codes.  

Vacuum Insulated Glazing.

Vacuum Insulating Glazing (VIG) technology, pioneered by Vitro and other manufacturers, offers remarkable thermal performance for windows. It features two glass panes sealed with a vacuum, creating a highly effective insulation barrier. This technology significantly reduces heat transfer, improving energy efficiency without compromising the architectural integrity of historic buildings. Vitro’s integration of VIG technology contributes to preserving these structures while enhancing their sustainability.

Electrochromic Glazing.

Electrochromic glazing is another type of dynamic glazing that changes its tint in response to an electrical current. This allows occupants to control the amount of light and heat entering the building, providing both energy savings and improved comfort.

T.FIN’s partner, SageGlass®, is the global leader in smart glass systems and offers a robust lineup of electrochromic glass products designed to tint automatically in response to the sun, delivering comfort, well-being and energy savings.

SageGlass recently completed an analysis to quantify Electrochromic Glazing’s impact on energy savings and found it resulted in an astounding 73 percent decrease in electricity consumption. Read the full study here.

Spectrally Selective Glazing. Spectrally selective glazing is designed to allow visible light to pass through while blocking unwanted heat
and UV radiation. This reduces cooling costs while allowing natural light to enter the building.

Updating a historical building’s windows will provide more benefits in the long run and can be a simple process when working with a knowledgeable partner to help select the right products for your project. T. FIN Building Solutions help our clients navigate the design process of product selection with validation and technical due diligence. We have partnered with high-end, select quality, innovative and time-tested daylighting and glazing products to meet and exceed every project’s design goals. Let our expertise help on your next historical project.

Learn about our team and explore all we have to offer at www.tfinbuildingsolutions.com or click here to contact us today.

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