JB Sash and Door has been Boston’s trusted name in historic window replacement for nearly a century. From Beacon Hill to the Back Bay, our JB Proper Bostonian replacement windows have seamlessly integrated into some of the city’s most iconic homes. Born from a legacy of expert millwork, we haven’t just replaced windows—we’ve meticulously recreated each one, ensuring every detail matches the original craftsmanship while enhancing energy efficiency and comfort.
Boston’s Architectural District Commissions uphold strict guidelines for historic window replacements, and our team knows them inside and out. With deep expertise in authentic replication, our craftsmen ensure every window not only meets approval but also honors the city’s architectural legacy.
With JB Sash, you don’t have to choose between tradition and innovation—our windows preserve the past while delivering the energy efficiency and comfort of today.
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We craft all of our JB Proper Bostonian replacement windows
in Chelsea, MA for true New England authenticity.
Custom Materials: Custom-made in pine, red grandis, or mahogany to fit any opening.
True Divided Lights: Insulated glass that reduces sound and increases energy efficiency.
Historic Accuracy: No visible jamb liner from exterior to maintain the historic appearance.
Upgraded Functionality: Tilt wash design for easy cleaning and maintenance.
Muntin Bar Customization: Available in the size required to meet your specifications.
Unique Styles: Available in bowed or radius top styles along with other historically accurate designs.
We offer a complete turnkey solution to meet your historic window replacement needs.
During an in-home consultation, our replacement expert will evaluate and measure your windows and doors, answer questions, talk through installation options and provide you with a free quote.
Comprehensive support from start to finish, including thorough photography, detailed drawings, complete Boston Landmark Commission permit application and approval, as well as full design, construction, and painting services.
Installation is an easy and hassle-free experience. Our dedicated team handles it all for you, and makes sure you’re satisfied.
All of our products are backed by manufacturer warranty, giving you peace of mind that your investment is protected.
Complete the form and you’ll be contacted by one of our helpful Marvin experts.
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