Storm windows and window inserts — the budget alternative

Staff

27 Jun 2025 — 4 min read

This article is for educational purposes only and is not a substitute for professional advice. Local codes, regulations, and best practices vary by region.

If your existing windows are old and inefficient but you can’t afford to replace them, storm windows and window inserts offer a cost-effective alternative. These additions provide significant efficiency improvements without the expense of full window replacement. Understanding the options helps you improve your home’s comfort and energy efficiency on a budget.

How Storm Windows Work

A storm window is an additional window installed on the exterior of an existing window. The storm window creates an insulating air space between it and the existing window. This air space reduces heat transfer significantly.

The outer window (the storm) protects the inner window from weather. Snow, ice, and rain don’t directly contact the original window as often.

Storm windows reduce heating costs by 10 to 25 percent depending on the existing window quality and the storm window quality.

Storm Window Types

Combination storm windows have fixed panels on the sides and removable central panels that can be replaced with screens in warm weather. This design allows you to remove the center panel in summer and open the interior window.

Full-frame storm windows have permanent fixed frames. They provide year-round protection and efficiency but don’t allow opening the existing window without removing the storm window.

Interior storm windows are installed on the interior side of existing windows. They’re less visible but somewhat less effective at protecting the exterior window from weather.

Window Inserts

Window inserts are removable frames with plastic or glass that fit inside the existing window frame. You install them on the interior before cold weather arrives and remove them in spring.

Window inserts are simpler to install than storm windows. They don’t require exterior access or fastening to the building exterior. Removable inserts are stored during warm months.

Window inserts provide similar efficiency benefits to exterior storm windows, typically reducing heat loss by 10 to 25 percent.

Cost Comparison

Storm windows cost $150 to $400 per window installed depending on style and quality.

Window inserts cost $50 to $150 per insert depending on materials and custom sizing.

Full window replacement costs $300 to $700 per window installed.

For a home with 20 windows, storm windows cost $3000 to $8000. Window inserts cost $1000 to $3000. Full replacement costs $6000 to $14000.

Storm windows or inserts can provide reasonable efficiency improvements at half the cost of replacement.

Installation and Maintenance

Storm windows are bolted or fastened to the building exterior. Installation requires exterior access and fastening hardware. Professional installation is common.

Window inserts are applied to the interior frame with adhesive or friction fitting. Installation is simple enough for DIY.

Both types require occasional maintenance. Weatherstripping and seals degrade over time and need replacement every 5 to 10 years.

Storm window frames need cleaning (exterior and interior) to remain transparent.

Window insert plastic can become brittle or cloudy after several years of sun exposure. Replacement every 5 to 10 years is typical.

Effectiveness and Performance

Storm windows reduce heat loss significantly if installed correctly. An old single-pane window with a storm window performs nearly as well as a modern insulated window.

Window inserts provide similar performance to storm windows but are slightly less effective because there’s less insulating air space.

Both options improve comfort near windows. Drafts are reduced, and cold surfaces are less obvious.

Both options reduce condensation on existing windows by keeping the inner window warmer.

Aesthetic Considerations

Storm windows are visible on the exterior. They add visual bulk. In some architectural styles, this is acceptable. In others, it’s considered less attractive.

Full-frame storm windows are more visible than combination storms that are removed in summer.

Window inserts are installed on the interior and aren’t visible from outside. Aesthetically, they don’t change the exterior appearance. On the interior, they’re visible and can look like plastic sheeting if not high-quality.

Preservation of Historic Windows

If you have historic windows you want to preserve, storm windows or inserts are appropriate alternatives to replacement. They improve efficiency without modifying the historic windows.

Building codes and local historic preservation guidelines sometimes require preservation of historic windows. Storm windows are an approved approach to upgrade efficiency while maintaining historic character.

Seasonal Considerations

Some storm windows use removable center panels that you replace with screens in summer. This allows you to open the interior window for ventilation. In winter, you remove the screens and install the storm panels for insulation.

Full-frame storm windows don’t allow opening the interior window without removing the storm window, which is more cumbersome.

Window inserts are removable and stored during warm months, allowing full operation of the original window during warm season.

Condensation Management

Condensation can form between the storm window and the existing window, especially in winter when temperature difference is great.

Proper drainage and weep holes prevent condensation from accumulating. Storm windows should include provisions to drain any condensation that forms.

Window inserts prevent condensation between the insert and the original window because they’re on the interior.

Lifespan and Durability

Storm windows last 20 to 30 years or longer depending on materials and maintenance.

Window inserts are more temporary, typically lasting 5 to 10 years before plastic becomes brittle or cloudy.

Both types can be maintained and resealed as weatherstripping degrades. Full replacement of either type is less expensive than window replacement.

When to Choose These Options

If your windows are original single-pane or older double-pane and you can’t afford replacement, storm windows or inserts improve efficiency significantly.

If you have historic windows that need to be preserved, storm windows are an approved method to upgrade efficiency.

If you want a temporary solution while you save for full window replacement, storm windows or inserts extend your timeline.

If budget is the primary constraint, storm windows or inserts provide efficiency improvements at lower cost than replacement.

The Reality

Storm windows and inserts are cost-effective ways to improve inefficient windows. They’re not as good as replacement with modern windows, but they’re significantly better than old windows alone.

Storm windows or inserts are appropriate interim solutions if you can’t afford full replacement yet. They improve comfort and reduce heating costs enough to be worthwhile. Eventually, when budget allows, full window replacement might be the next step.