WINSERT INSTRUCTIONS

How to make a WINSERT (winter insulated window insert)
Method adapted and developed by Brian Nugent, 2007

Tools and materials
Step 1: Measuring
Step 2: Making the frame
Step 3: Water-sealing the frame
Step 4: Applying the tape
Step 5: Attaching the plastic film
Step 6: Pull tabs
Step 7: Foam tape
Installation and care

WINSERT FAQs

What are they?

"Winserts" are reusable transparent panels that fit snugly inside window jambs to add two extra layers of glazing.

How do they work?

The winsert uses two closely-spaced sheets of plastic to create a layer of "dead air" next to your window. This keeps warm air from the building from moving out to the colder air outside. While a single layer of plastic sheeting can help reduce heat loss from your windows, it does not usually create this insulating layer of dead air and may actually leave enough space for a convection current to form that pulls heat away from the living space. We believe that a properly-constructed winsert can reduce heat loss from a typical single- or double-glazed window by up to 50%. The design was inspired by a long-forgotten FEMA website and has been adapted by Brian Nugent and other North Quabbin Energy members and participants in our workshops. We hope you will feel free to improve it further or adapt it to your particular needs.

How complicated are they to make?

Winserts require some basic woodworking equipment and skills to make, particularly in the construction of the frame. If you don't have these yourself, you should try to find someone who does--perhaps you can work together to make winserts for both of you! Attaching the plastic and foam is easy to do.

How long will they last?

This method is a work in progress, and we don't have reliable reports yet about the life expectancy of the various types of winserts that have been made. A first-generation method, which used slightly heavier vinyl but was more complicated to make, should last at least five years with careful use and storage. The newer method described here, using heat-shrink plastic film, may be somewhat less durable over the long run. With good care, though, the heat-shrink winserts should last several years. The plastic or vinyl is the component that is most likely to need replacing; the long-term strength of the double-sided tape used in the heat-shrink method is also not known yet. However, the frames could be re-covered with new plastic film if needed.

Note:

Brian Nugent and North Quabbin Energy offer these construction methods as a suggestion of one way to weatherize your home. We make no guarantee of the results of making or installing winserts, but we believe that if you follow this method, you will notice a difference in the heat loss through your windows. We welcome feedback (email us at info@northquabbinenergy.org), and we invite you to adapt the design, make suggestions for improving it, and pass the results along to us and to others. As we all search for creative ways to reduce energy use and improve efficiency, we hope that more do-it-yourself ideas like this can be developed, improved, and shared. (For discussion about similar designs, visit the Historic HomeWorks Forum and Topher Belknap's design.)