Replacing a window frame will improve your home’s energy efficiency if the old frame is cracked or damaged in a way that allows unconditioned air from the outside into your living space or if you upgrade to a more energy-efficient window frame material. Aluminum is the least energy-efficient window frame material, followed by vinyl and wood. Fiberglass and composite frames are the most energy-efficient.

Whether window film is better depends on individual preferences and specific needs. In some instances, window film can be much less costly to install. Aesthetics is also a deciding factor. Window film may have a more significant appeal for design minimalists looking for a clean and streamlined look without the heaviness that comes with curtains. On the flip side, they can also appeal to design maximalists looking for creative expression in the form of color, patterns, and texture. Choosing between window film and traditional window coverings depends on factors like desired functionality, aesthetics, and personal preferences.

The most energy-efficient windows are double—or triple-pane windows with low-emissivity (Low-E) coatings and gas fills between the panes. These windows reduce heat transfer, prevent drafts, and help maintain a consistent indoor temperature. But if replacing windows isn’t in your budget, pairing your existing windows with insulating window treatments can still make a noticeable difference in home comfort and monthly bills. 

Cellular shades, also known as honeycomb shades, are the most energy-efficient and insulating window treatments. Their honeycomb structure is made of soft fabric that forms layered cell pockets. These pockets trap air, creating a thermal barrier that reduces heat loss in the winter and blocks heat gain in the summer. For even greater insulation, consider double- or triple-cell varieties. Side-tracked cellular shades, which seal the edges of the window frame, can further minimize air leaks and maximize energy efficiency.