Choosing between storm windows vs replacement windows comes down to the condition of your existing windows. If your current windows are structurally sound, energy-efficient storm windows can deliver energy savings similar to full replacement at about one-third the cost, according to the U.S. Department of Energy (DOE).

You may not need to remove your original windows to make your home more comfortable. Metro Screenworks, a family-owned screen company in Colorado since 1979, offers custom storm windows built to fit your existing openings, helping reduce drafts and improve insulation while you keep the windows you already have. Here's how to decide which investment makes sense for your home.

What Is the Difference Between Storm Windows and Replacement Windows?

The main difference is what happens to your existing window. Storm windows add a protective layer of glass or another clear material over the window already installed. Replacement windows remove the existing window unit and install a new one. Both can improve comfort and energy efficiency, but they solve different problems.

What Are Storm Windows?

Storm windows are secondary windows installed on the exterior or interior of an existing window. They add a barrier against outside temperatures, wind, and drafts without removing the original window.

Older storm windows typically used clear glass, while newer models are available with a low-emissivity (low-e) coating that reduces heat transfer through the storm window, according to the DOE.

By adding a layer of protection and an insulating air space, storm windows improve the thermal performance of older windows. They are especially useful for single-pane windows and historic homes where keeping the original windows matters.

What Are Replacement Windows?

Replacement windows involve removing an existing window unit and installing a new one. Depending on the project, this can mean replacing the sash, frame components, or the complete window assembly.

Modern replacement windows may feature insulated glass, updated frame materials, improved seals, and energy-efficient coatings. They are often the better solution when existing windows are deteriorating, hard to operate, or beyond practical repair.

Storm Windows vs. Replacement Windows at a Glance

Comparing storm windows vs window replacement side by side shows the core distinction: storm windows improve what's already there, while replacement windows let you correct problems with the window itself.

Neither option wins in every home. The right choice depends on your existing windows, your budget, and what you want the project to accomplish.

Do Storm Windows Save as Much Energy as Replacement Windows?

Energy-efficient storm windows can save about as much energy as replacement windows when low-e storm windows are installed over older single-pane windows. In side-by-side testing referenced by the DOE, a low-e storm window over a single-pane window performed about the same as a new double-pane low-e replacement window.

That makes storm windows worth considering before you commit to a full replacement project.

According to ENERGY STAR, certified low-e storm windows installed over single-pane clear glass windows with no existing storm windows can save homeowners about $350 a year on heating and cooling, or about 10% on a national-average basis.

If you already have clear-glass storm windows and replace them with certified low-e storm windows, ENERGY STAR estimates you can save about another $50 a year, or about 2%.

The DOE also lists potential annual energy savings of 12% to 33% for exterior low-e storm windows, depending on the home.

Your actual results depend on climate, utility rates, existing glass, insulation, air leakage, and the condition of the window. Homes with older single-pane windows see the biggest improvement, while homes with clear double-pane windows see smaller savings and a longer payback.

Why Low-E Glass Matters for Energy-Efficient Storm Windows

Low-e glass has a thin, nearly invisible coating that reduces the transfer of radiant heat through the window. In colder months, it helps keep indoor heat inside. In warmer months, it can reduce unwanted heat gain, depending on the coating.

Research from the DOE found that a low-e coating improves energy savings by about 10% to 15% over standard storm windows without the coating. The same research found low-e storm windows cost-effective in all U.S. climate zones, with an average payback of two to four years.

When comparing products, look at the glass type, ENERGY STAR certification, and performance ratings from the Attachments Energy Rating Council (AERC).

All six of our storm window configurations are available with low-e glass, so you can choose the energy-efficient option for any window in your home.

Storm Windows vs. Replacement Windows: Cost

Storm windows cost less than replacement windows because they work with your existing window instead of replacing it. According to the DOE, low-e storm windows cost about one-third as much as full window replacement, though the exact difference depends on the products, installation, and condition of your existing windows.

That difference adds up quickly when you're upgrading several windows throughout a home.

When comparing storm windows vs window replacement, look at the full project instead of the price of a single window. Replacement projects can involve more labor, removal of existing materials, and repairs to surrounding trim or framing.

Storm windows require a lighter installation, which makes them a good fit for homeowners who want more comfort without taking on a larger renovation.

What Affects Storm Windows Prices?

Storm windows prices depend on the window's dimensions, configuration, frame color, glass selection, and added features.

Our custom-sized aluminum storm windows fit double-hung, horizontal sliding, and picture window openings. You choose the configuration that matches your existing window, add low-e glass if you want it, and we build each unit to your measurements.

For current pricing, browse our storm windows collection and compare configurations and glass options before you decide.

For whole-home projects or multiple properties, request a quote and our team will help you plan the order.

When Are Storm Windows the Better Choice?

Storm windows are often the better choice when your existing windows still work well but need better insulation, draft reduction, or weather protection. They let you keep your existing windows while improving everyday comfort at a lower overall cost.

Consider storm windows in these situations:

Your existing windows are structurally sound. If the frames and sashes are in good condition, a storm window improves thermal performance without replacing parts that still work.

You have older single-pane windows. According to ENERGY STAR, the biggest savings come from installing certified low-e storm windows over single-pane clear glass.

You want to preserve historic windows. Original wood windows add to a home's architectural character. Storm windows let you keep those details while improving insulation.

You deal with drafts or outside noise. The DOE lists reduced drafts, better comfort, and reduced noise among the benefits of storm windows.

You're working with a set budget. Storm windows upgrade window performance without committing you to a full replacement project.

For many homeowners, the deciding question is simple: do your existing windows need to be replaced, or do they need to perform better?

When Are Replacement Windows the Better Choice?

Replacement windows are the better choice when the original window is damaged, deteriorating, or no longer working properly. Storm windows improve the performance of an existing window, but they do not repair rotting frames, damaged sashes, or structural problems. Those issues need to be addressed first.

Full window replacement makes more sense when:

• Window frames show significant rot or structural damage.
• Sashes are damaged or no longer operate safely.
• The window has recurring problems that practical repairs can't fix.
• You want to change the window's style, material, or overall design.

The benefits of full window replacement vs storm windows come down to this: storm windows upgrade the window you have, and replacement gives you a new window assembly.

If you have clear double-pane windows, storm windows can still help, but ENERGY STAR notes the payback takes longer than it does over single-pane glass.

Before you choose, check the condition of the original frames and moving parts. Adding a storm window over deteriorating materials will not remove the need for repairs.

Exterior vs. Interior Storm Windows

Exterior storm windows mount outside the existing window, while interior storm windows and inserts install on the room-facing side. Both add a second barrier, and they differ in appearance, access, and installation. The right option depends on your windows, any building rules, and whether you want something removable.

Exterior Aluminum Storm Windows

Aluminum storm windows are a popular choice for homeowners who want a durable, custom-fitted secondary window.

Our exterior storm windows are pre-framed aluminum, built to your measurements, and shipped ready to install. Once installed, they create an insulating air space between your existing window and the storm window.

The choice between two-track and three-track designs depends on how you want the glass and screens to operate. For example, our three-track slider lets both panels slide in either direction and includes a full removable screen system, while other configurations offer different ventilation setups to match your window.

Interior Storm Windows and Window Inserts

Interior storm windows are a good alternative when exterior installation isn't practical.

They work well for renters, condo owners, and homeowners who want to keep the outside of the building unchanged. If you rent or have an HOA, check with your landlord or association before installing.

Our Draft Blocker is a removable interior storm window insert made with 20-gauge clear vinyl in an aluminum frame. Each one is made by hand in Colorado and sized in 1/16-inch increments, so it fits inside your existing window opening and can be removed and reused each season.

Because it uses clear vinyl instead of glass, the Draft Blocker is a lightweight, removable way to cut drafts, and a separate product from a low-e glass storm window.

For porches, patios, and other seasonal enclosures, explore our vinyl screens and panels.

Which Storm Window Style Fits Your Windows?

The best storm window configuration depends on how your existing window opens and how you want to control airflow. We offer six custom configurations, and every one is available with low-e glass:

Before ordering, note whether your original window opens vertically, slides horizontally, or stays fixed. Matching the storm window to your window keeps it working the way it does now, with added protection.

How to Measure for Storm Windows

Accurate measurements are essential for a proper storm window fit. The DOE recommends measuring the opening width at the top, middle, and bottom, then using the smallest of the three when you order.

Follow the measuring instructions for your specific storm window product. If you have questions before ordering, contact our team or call 1-800-413-2579 and a screen specialist will help.

Storm Windows vs. Replacement Windows FAQ

Are storm windows worth it?

Yes, storm windows are often worth it when your existing windows are structurally sound, especially in homes with older single-pane glass. ENERGY STAR points to certified low-e storm windows as an affordable upgrade for homes where full replacement is difficult or expensive. Your results depend on your existing windows and climate.

Can I install storm windows myself?

Yes, many exterior storm windows are designed for homeowner installation. The DOE describes installing exterior low-e storm windows as an easy project that takes about 20 to 30 minutes per window. Follow the manufacturer's instructions, and use a professional when the opening is hard to reach.

Do storm windows reduce outside noise?

Yes, properly installed storm windows can help reduce outdoor noise by adding another barrier between the inside and outside of your home. The DOE lists noise reduction as one of the benefits of storm windows. Results vary with your existing window, the storm window, the fit, and the source of the noise.

Do storm windows cause condensation?

Condensation can form between a storm window and the original window when moisture gets trapped in the space between them. Proper installation and drainage prevent most of it. Weep holes at the bottom of an exterior storm window frame let moisture escape and reduce the risk of trapped condensation, according to the DOE.

Can storm windows stay installed year-round?

Yes, modern storm windows can stay installed all year. Operable designs let you open your windows for fresh air while keeping the extra layer of protection in place, and the DOE recommends keeping storm windows up year-round. Low-e storm windows help in both heating and cooling seasons.

Are storm windows ENERGY STAR certified?

Some storm windows are ENERGY STAR certified. ENERGY STAR certifies storm windows that use low-e glass and meet its performance requirements, so not every storm window qualifies. Check a product's glass type and certification before assuming it delivers the savings described above.