Insulate & Preserve Historic Windows with SLIP™.
Improve the efficiency of your historic home’s windows without compromising on style or function.

Order Your Customized SLIP System

Follow Our Simple Installation Process

Enjoy The Results
Our Clients






Older Windows Undermine Your Home’s Heating
Single-pane windows just aren’t up to today’s energy efficiency standards. This can cause air leaks that lead to your HVAC system working harder to heat and cool your home. Old windows often feature charming woodwork, stained glass panes, and other thoughtful details. All of that adds up to hefty price tags for replacement windows.


Avoid Damage and Costly Window Replacement
Storm windows provide temporary relief but block access to window functionality while installed. Inefficient windows let heating and cooling escape from your home, leading to higher energy costs. While temporary solutions from home improvement stores and various window inserts are an option, they’re a band-aid for a larger problem.
Energy Saving Vintage Window Insulation Solution
Save up to 72% on your home’s utility costs. The most effective solution on the market is Window SLIP. Our inserts will reduce air leaks and improve the functionality of your historic windows.
Heritage Board Approved
If your home is protected under the National Register of Historic Places, you know how tricky home improvements can be. Window SLIP upgrades your windows with an ultra-low profile. This means your original word work and details shine through unharmed.
Improved Efficiency
Your home’s energy use is greatly impacted by the air flow throughout the home. Many of our customers enjoy energy savings and find their home cooler in the summer and warmer in the winter. It’s amazing what adding panes of glass can do for your home’s energy use.
Improved Functionality
While you can find a good storm window, it still won’t allow for the functionality of the windows. And especially in older homes, the original windows may even be painted shut. Window SLIP fixes functionality while providing a permanent solution.

How Do Our Window SLIPs Work?
Window SLIPs are custom-made to fit the exact specifications of your residence or business. They are installed by contractors, architects, or licensed professionals. Because of their slim lines and clear glass– they’re nearly invisible once put on your window.

Custom Fabrication
Each SLIP is custom-fabricated to match the daylight opening of the sash and mounts securely to the interior or exterior face of the sash, depending on configuration. The system includes a slim-profile aluminum frame and high-performance glass, installed by trained contractors or preservation professionals. The low-profile frame can be painted to match your window and disappear. This allows your original window to show through as if no alterations were made.

Professional Installation
Windows remain fully operable, and in some cases, painted-over or damaged windows can be fixed utilizing Window SLIPs. Our systems come with all installation hardware included. In your package you’ll find hanging balances, weatherstripping, screws, and tabs.
Questions about Installation? Check out our Frequently Asked Questions page or this how-to video.

Energy Saving Benefits
The homeowners experience all the benefits of double-pane windows, without the price tag of full replacement. Our customers report cost savings of over 72% on their energy bills. They also notice reduced noise and no more moisture.
What Types of Windows Can We Create SLIPs For?
Single Pane Windows
Window SLIPs add a second layer to single-pane windows, creating insulation similar to double-pane quality.
Single-Hung Windows
Double-Hung Windows
Casement Windows
Leaded Windows
Stained Glass Windows
Arched Windows
Historic Preservation Board Approved
Before you begin work on a historic home, there are guidelines from city, state, and federal preservation boards you may need to follow. We have worked on many historic buildings and homes, and Window SLIP is a great, board-approved option for many homes and businesses. Preserve your building’s personality and character while modernizing its energy efficiency; it’s a win-win.
Historic Registry Regulations
Completing repairs on your home can mean checking with several registries about guidelines. We make it easy for you with a low-profile SLIP that doesn’t harm your historic windows. The National Historic Registry recommends:
“Identifying, retaining, and preserving windows from the restoration period and their functional and decorative features. The window material and how the window operates (e.g., double hung, casement, awning, or hopper) are significant, as are its components (including sash, muntins, ogee lugs, glazing, pane configuration, sills, mullions, hardware, casings or brick molds) and related features, such as shutters.”
Window SLIP Delivers Custom Solutions
Our slips are non-invasive and won’t alter the beauty of your historic windows. Because of their low profile and clear appearance, the original details will remain visible. Our solutions make both homeowners and historic boards happy. They provide modern comforts and functionality while preserving the history of the building.

Why Choose Us
Window SLIP is part of Chosen Wood Window Maintenance, a premier residential and commercial full-service window contractor. Our team has decades of experience in window restoration and repair. We’re passionate about maintaining the beauty of historic homes, and that drove us to create Window SLIP as a way to improve efficiency without compromising the charm of older windows.
Testimonials
Backed by a Ten Year Warranty
Our SLIPs are guaranteed to withstand regular wear and tear for a decade. We require professionals who install our products to provide a 1-year warranty on installation as well. With proper maintenance, our SLIPs can easily last for the life of your windows.
Contact Us Today to Get Started
With decades of experience repairing, retrofitting, and restoring wood windows, we’re the industry experts. We’ve designed Window SLIPs to meet the unique needs of contractors working on historic residences and businesses. To improve energy efficiency, see a reduced heating bill, and maintain the historic charm of vintage windows, contact us for a FREE quote today!