Storm Windows & Doors: Modern Options for Energy Savings

Storm windows offer a cost-effective alternative to full window replacement for improving energy efficiency. According to the U.S. Department of Energy, storm windows can reduce energy loss through windows by 10-30%—at a fraction of the cost of replacement.

This guide covers modern storm window and door options, helping homeowners evaluate whether storms are the right efficiency investment for their situation.

How Storm Windows Work

The Insulating Principle

According to Lawrence Berkeley National Laboratory, storm windows improve efficiency by:

1. Adding an air gap: Creates additional insulating layer
2. Reducing air infiltration: Seals drafts around primary windows
3. Protecting primary windows: Shields from weather exposure
4. Optional Low-E coating: Reflects heat back into home

Performance Impact

According to DOE research, adding storm windows to single-pane windows:

Configuration | Approximate U-Factor

Single-pane, no storm | 0.90-1.10

Single-pane + storm | 0.45-0.55

Double-pane, no storm | 0.45-0.55

Double-pane + storm | 0.30-0.40

The Efficient Windows Collaborative notes that storm windows can effectively give single-pane windows double-pane performance.

Types of Storm Windows

Exterior Storm Windows

According to the FGIA, exterior storms are the traditional approach:

Traditional (Triple-Track)

• Three horizontal tracks (two glass, one screen)
• Self-storing (no seasonal removal)
• Aluminum or vinyl frames
• Mount to exterior window casing

Fixed Panel

• Single glass panel, no screen
• Maximum weather protection
• Must be removed for ventilation
• Lower cost than triple-track

Low-E Storm Windows

• Glass with Low-E coating
• Better energy performance
• Higher cost, higher benefit
• According to DOE, can save 12-33% on heating/cooling

Interior Storm Windows

According to LBNL research, interior storms are increasingly popular:

Advantages over exterior:

• Better energy performance (warmer interior surface)
• Easier to install and maintain
• No ladder access required
• Don't alter exterior appearance (good for historic homes)
• Can be removed seasonally

Types:

• Magnetic mount (magnets seal to metal frame)
• Compression fit (friction holds in place)
• Track-mounted (permanently installed tracks)
• Acrylic or glass panels

Storm Window Glazing Options

According to the FGIA:

Glazing Type | Benefits | Best For

Single clear glass | Basic protection, low cost | Budget projects

Low-E glass | Better energy performance | Maximum efficiency

Laminated glass | Sound reduction, safety | Noise-sensitive locations

Acrylic/polycarbonate | Lightweight, impact resistant | DIY, temporary

Energy Savings Potential

DOE Estimates

According to the U.S. Department of Energy, storm window savings depend on:

Existing Windows | Storm Window Type | Estimated Savings

Single-pane | Standard storm | 12-25%

Single-pane | Low-E storm | 25-33%

Older double-pane | Standard storm | 5-15%

Older double-pane | Low-E storm | 10-20%

Regional Variation

According to ENERGY STAR guidance, savings vary by climate:

• Cold climates (Idaho): Higher savings potential (more heating hours)
• Mild climates: Lower absolute savings
• Mixed climates: Moderate savings

Return on Investment

According to analysis from LBNL:

Storm Window Type | Installed Cost | Annual Savings | Payback

Standard exterior | $75-150/window | $15-40 | 3-7 years

Low-E exterior | $150-250/window | $25-60 | 4-8 years

Interior magnetic | $100-200/window | $20-50 | 3-6 years

Storm windows typically provide faster payback than full window replacement, according to DOE analysis.

Comparing Storms to Window Replacement

When Storms Make More Sense

According to the U.S. Department of Energy and Efficient Windows Collaborative, storms are better when:

• Primary windows are structurally sound
• Historic preservation is a concern
• Budget is limited
• Primary windows have character you want to preserve
• Existing windows are double-pane (diminishing returns from replacement)

When Replacement Makes More Sense

According to DOE guidance, replacement is better when:

• Primary windows are damaged, rotted, or failing
• Windows don't operate properly
• Air leakage is severe (beyond what storms address)
• You want maximum efficiency improvement
• Aesthetic update is desired
• Tax credits offset replacement cost

Hybrid Approach

The Efficient Windows Collaborative notes that combining approaches can optimize results:

• Replace worst-condition windows
• Add storms to salvageable windows
• Prioritize high-use areas for replacement
• Use storms elsewhere

Storm Door Options

Purpose and Benefits

According to the FGIA, storm doors provide:

• Protection for entry doors
• Additional weather barrier
• Screen option for ventilation
• Security (glass + primary door)
• Curb appeal options

Types of Storm Doors

According to FGIA product categories:

Full-View Storm Doors

• Maximum glass area
• Interchangeable glass/screen panels
• Shows off entry door
• Premium appearance

Mid-View Storm Doors

• Glass in upper portion
• Solid panel below
• Balance of light and durability

Self-Storing Storm Doors

• Built-in screen that slides up/down
• No seasonal panel changes
• Convenient operation

Ventilating Storm Doors

• Retractable screen built-in
• Full glass or venting options
• Premium convenience

Energy Considerations

According to the U.S. Department of Energy:

• Storm doors provide modest energy benefit over well-sealed entry doors
• Primary benefit is protecting entry door from weather
• Can trap heat against entry door (concern with south-facing doors)
• Dark-colored entry doors + storm doors may cause overheating

DOE recommendation: Consider light-colored entry doors or vented storm doors for sun-exposed entries.

Installation Options

Professional Installation

According to FGIA guidance, professional installation ensures:

• Accurate measurement
• Proper fit and sealing
• Correct mounting
• Warranty protection
• Especially recommended for exterior storms

Typical costs:

• Storm windows: $50-100 per window for labor
• Storm doors: $100-200 per door for labor

DIY Installation

According to DOE guidance, DIY is feasible for:

• Interior storm windows (especially magnetic)
• Pre-sized exterior storms
• Homeowners comfortable with basic tools
• Simple installations on accessible windows

Considerations:

• Accurate measurement is critical
• Sealing requires attention to detail
• Tall windows may require ladder work
• Interior storms are more DIY-friendly than exterior

Selecting Storm Windows

Key Features to Consider

According to the Efficient Windows Collaborative:

Feature | Why It Matters

Frame material | Durability, appearance, thermal performance

Glazing type | Energy performance, clarity

Weatherstripping | Air sealing effectiveness

Hardware quality | Long-term operation

Finish options | Aesthetics, UV resistance

Weep holes | Drainage to prevent moisture problems

Frame Materials

According to FGIA:

Material | Pros | Cons

Aluminum | Durable, low maintenance, affordable | Higher conductivity, potential condensation

Vinyl | Good insulator, low maintenance | May warp in extreme heat

Wood | Traditional appearance, good insulator | Requires maintenance

Composite | Durability + aesthetics | Higher cost

Low-E Storm Windows

According to LBNL research, Low-E storms provide:

• 12-33% greater energy savings than standard
• Reduced interior condensation
• UV protection for furnishings
• Warmer interior surface

The U.S. Department of Energy recommends Low-E storm windows for maximum benefit in cold climates like Idaho.

Historic Home Considerations

Preservation Benefits

According to the National Park Service, storm windows:

• Preserve original windows intact
• Are reversible (can be removed without damage)
• Protect historic windows from weather
• Allow restoration rather than replacement
• Generally approved in historic districts

Appearance Considerations

According to NPS guidance for historic properties:

• Select storms that don't obscure historic window profiles
• Choose frame colors that complement (or match) window frames
• Consider interior storms for minimal exterior impact
• Avoid storms with wide meeting rails that visually divide windows

Maintenance and Care

Routine Maintenance

According to FGIA care guidance:

• Clean glass seasonally (interior and exterior surfaces)
• Inspect weatherstripping annually
• Lubricate tracks and hardware
• Check for drainage blockages
• Touch up frame finishes as needed

Common Problems

According to DOE and FGIA troubleshooting:

Problem | Likely Cause | Solution

Condensation between storm and primary | Poor seal, high humidity | Improve sealing, reduce interior humidity

Difficult operation | Dirty tracks, paint buildup | Clean and lubricate

Air leakage | Worn weatherstripping | Replace weatherstripping

Frame corrosion | Age, moisture exposure | Clean, treat, possibly replace

The Bottom Line

According to the U.S. Department of Energy and Lawrence Berkeley National Laboratory, storm windows remain one of the most cost-effective energy efficiency improvements available:

• Lower cost than window replacement
• Faster payback period
• Preserve existing windows
• Reversible installation
• Appropriate for historic homes

For Idaho homeowners:

• Storm windows are well-suited to Idaho's heating-dominated climate
• Low-E storm windows maximize savings in cold winters
• Interior storms offer easy installation and strong performance
• Consider storms before committing to full window replacement
• Especially valuable for homes with single-pane windows

A qualified window professional can assess your specific situation and recommend whether storm windows, window replacement, or a combination provides the best value for your home and budget.