The All-In-One Storm Window Solution for Historic Projects.
Window SLIP is the complete sash-mounted thermal upgrade for historic windows. This precision-fabricated system, built to spec and delivered ready for professional installation, is complete with all required components and labeling.
Our Clients
Traditional Storm Windows Need a Rework
Many traditional historic storm windows and seasonal inserts provide only marginal performance and block access to window functionality while installed. Rather than settling for temporary fixes that require seasonal reinstallation, our SLIP system offers a professional, permanent solution for your historic windows. This non-invasive thermal upgrade ensures your vintage windows remain historically accurate and fully operable, potentially saving you up to 72% on energy costs.
See more installed SLIPs in our photo gallery.
The Frustrating Truth About Traditional Storm Windows and Panels
- Traditional storm windows provide temporary relief but often block window functionality while installed.
- Temporary storm products or films offer only marginal energy performance and require recurring labor or replacement every season.
- Store-bought insulation options lack the proven thermal performance and often force you to sacrifice natural light or window operation.
- You need a long-term, low-profile secondary glazing system that delivers double-pane efficiency without compromising the window’s original charm or function.
The Slim Line Insulating Pane: A Permanent Storm Window Alternative
Window SLIP delivers the long-term performance and functionality that seasonal storm windows or temporary inserts simply cannot match. It’s the high-efficiency upgrade that preserves your windows.
- Unlike generic window inserts or standard storm windows, SLIPs are custom-fabricated for each sash, guaranteeing a precise thermal seal and optimal performance.
- Full window operability is maintained (double-hung, casement, etc.), ensuring you can still open your windows freely, a major benefit over traditional storm products that block function.
- The sleek, slim-profile secondary glazing system installs permanently to the sash, retaining the original appearance and eliminating the need for seasonal installation or removal.
- SLIPs provide tested energy efficiency comparable to EnergyStar-rated alternatives, transforming single-pane windows into simulated double-pane quality without costly replacement.
- Our Window SLIP System is proven to reduce window-related energy bills by up to 72%Â while also delivering enhanced noise reduction.
Built for contractors, architects, and preservation teams.
Testimonials
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. 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
Windows with a single fixed sash and one operable sash can easily be fitted for window SLIPs while maintaining functionality.
Double-Hung Windows
Double-hung windows can be fitted for SLIPs while keeping the windows functioning properly.
Casement Windows
Leaded Windows
Stained Glass Windows
Arched Windows
Window SLIPs can be custom-fabricated for arched windows for a cost-effective insulation solution for beautiful historic windows.
Fully Customized To Your Exact Specs
We create each Window SLIP to order from products made in the USA. To ensure good quality, we ask you to provide the measurements of each window. We make them individually to fit the unique sash of each historic and vintage window.
Bulk Orders & Commercial Projects
For larger buildings and projects, we’re happy to work with you to create Window SLIPs in bulk. Whether you’re working in commercial or industrial settings or with residential customers, we’re here to help.
Customization for Residential, Commercial, and Industrial Needs
We’re able to create SLIPs for curved windows, handle custom paint colors, and assist with installation on large-scale projects as well. Contact us for more information about our offerings for your project.
Installation Guidance
What You’ll Find With Each System
Each system is sent via freight shipping directly to you with each Window SLIP securely packaged and labeled.
Your Custom SLIPs
All The Hardware You Need
No additional hardware store runs are needed, our systems come with hardware including weatherstripping, hidden balances, screws, and tabs labeled with their window pairings as well. We make it easy for you to impress your customers with a fast and efficient install!
Frequently Asked Questions
How Do I Become a Certified Installer for Window SLIP?
Do You Offer Bulk Pricing for Contractors or Commercial Clients?
What is the Shipping Time for Bulk or Custom Orders?
Our typical order turnaround time from placing the order to delivery is 8-10 weeks. For extra-large or customized orders, that may change. Contact us with the details for your project for the most accurate quote on how much time we’d need to produce and ship your SLIP system.
Still have questions? Check out our Frequently Asked Questions page for more information.
Backed by a Ten Year Warranty
Our SLIPs are guaranteed to withstand regular wear and tear for a decade. 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. Request a quote for SLIP units and hardware for your project. Pricing covers fabrication and shipped components; installation is completed by you or your preferred contractor.