About
KSP Construction specializes in the restoration and performance upgrade of historic steel windows throughout NYC, with a focus on Brooklyn brownstones and landmark properties. Our services include rust removal and stabilization, reglazing, frame repair, repainting, refinishing, and interior casement restoration — all while preserving original steel profiles and architectural character. We also provide new custom steel window systems designed to complement historic aesthetics.
Where improved thermal performance is required, we integrate modern IGU or advanced VIG (Vacuum Insulated Glass) into existing steel frames in select applications, delivering significant energy efficiency improvements without altering historic sightlines. Our approach combines preservation craftsmanship with modern glass technology to restore, upgrade, or install new steel window systems while maintaining the integrity of the building.
Testimonials
“Some of our windows were too far gone to save, while others just needed restoration. KSP was honest about what made sense. They restored most of the originals and fabricated new steel units where necessary. The transition between restored and new is seamless. They also discussed advanced glass options with us for better efficiency, which we appreciated. Overall, it felt like they were focused on doing what was right for the building.”
Angela L., Fort Greene, Brooklyn“Our brownstone gets a lot of wind exposure, and the windows were starting to feel inefficient. KSP suggested keeping the original steel frames and upgrading the glass instead of replacing them. They used a high-performance glass option that improved comfort without changing the appearance. From the street, nothing looks different — which was important to us.”
David R., Brooklyn Heights, Brooklyn“We thought we were going to have to replace all of our steel windows because of the rust and drafts. KSP walked us through what could actually be restored and what didn’t need to be replaced. They removed the rust, repaired the frames, and refinished everything carefully. In one area, they also upgraded the glass to improve insulation, and we’ve definitely noticed the difference this winter. The windows still look completely original.”
Sarah M., Park Slope, BrooklynWhat can we do for you?
Send us an email to get a quote, schedule an appointment or learn more.