Is It Worth Replacing 20 Year Old Windows?

The decision of whether to replace 20 year old windows is one that homeowners face as their windows age and become less energy efficient and durable. The key questions to consider are: How much have windows technologically improved in 20 years and will new windows provide better insulation, UV protection, easier maintenance, and operational smoothness? Will the costs of purchasing and installing new windows pay off long-term in energy savings and home resale value? What are the latest window styles, frame materials, glazing options, and smart features? This article examines if investing in replacing 20 year old windows is ultimately worthwhile.

Age of Windows

Most windows have a lifespan of around 20-25 years before they may need replacement. At around 20 years old, windows may start showing signs of wear and deterioration due to prolonged exposure to weather and general usage over the years (CITE: Typical issues seen in older windows include draftiness, rotting frames, loose glass panes, warped sashes and higher energy costs. The seals and weatherstripping around the window panes can also degrade over time, leading to air leaks, moisture buildup and heat loss. Replacing aging 20 year old windows before the onset of these major issues can help avoid bigger problems down the line.

While some well-maintained 20 year old windows may still be functional, their energy efficiency properties are likely outdated compared to new products on the market today. Newer windows with advanced glass, improved framing and multi-pane construction can offer drastically better insulation for your home. Upgrading 20 year old single pane windows to new double or triple pane windows can yield significant energy savings and improved comfort indoors. Though replacing functioning 20 year old windows does require an investment upfront, homeowners can often recoup costs long-term through utility bill savings from increased energy efficiency (CITE:

a homeowner examining a 20 year old window with peeling paint and cracked glazing


The energy efficiency of windows depends greatly on their age and condition. Older single-pane windows can be very drafty and allow significant air leakage, leading to higher heating and cooling costs. According to this source, air leakage accounts for 5-30% of home energy loss. Newer double-pane windows with improved framing and insulation around the edges can reduce air infiltration and better insulate the home.

Advances in window technology over the past 20 years have also improved energy efficiency. Modern windows often have low-emissivity (low-E) coatings on the glass to reduce heat transfer and retain interior temperature better. They may also have inert gas fills like argon between the panes for additional insulation. Upgrading from single pane to high-performance double pane windows can reduce heating and cooling costs by 10-12%, according to energy experts.

That said, as pointed out in this article, restoring and weatherizing old wood windows can also offer energy savings compared to no action. Simple fixes like sealing cracks, adding storm windows, and insulating frames can make old windows perform almost as well as new ones. So replacement is not always necessary for efficiency gains.

Maintenance of 20 Year Old Windows

Twenty year old windows will often need more maintenance and repairs compared to new windows. The hardware and seals in particular can start to fail on older windows.

The seals around the window panes in 20 year old windows can degrade over time, according to a Reddit user, leading to air leaks and drafts. Replacing the seals and weatherstripping can help, but it may be difficult finding replacement parts for windows this old (Reddit).

The hardware like hinges, locks, and window sash lifts also tend to wear out and may need replacing after 20 years. Windows from the 1990s and earlier sometimes used metal components that can corrode or rust (Ecotech Windows). Newer windows often have upgraded hardware made with more durable materials.

Older single pane windows can also develop condensation issues and be less energy efficient. New modern windows offer double or triple glazing that improves insulation. The glass itself on new windows is also often higher performance and better at blocking UV rays.

Overall, 20 year old windows will likely need more frequent repairs and part replacements versus new windows that should be maintenance free for at least 5-10 years after installation.

Costs for Replacing 20-Year-Old Windows

According to Modernize, the average cost to replace a single window is $234-$1,224, with most homeowners spending $615 per window on average (Source 1). So for a typical home with 20 windows, homeowners can expect to spend $12,300-$24,480 for the full replacement job.

The costs can add up quickly, but repairing older, damaged windows repeatedly can also get expensive. Replacing aging windows entirely offers more energy savings and durability in the long run. According to This Old House, new energy-efficient windows can reduce heating and cooling costs by up to 15% (Source 2).

When budgeting for window replacement, homeowners need to account for the window materials, labor costs for installation, permits and disposal fees for the old windows, and more. Vinyl or composite replacement windows tend to be the most affordable options. Hiring professional installers also adds labor costs, but helps ensure proper installation and no damage to the home’s structure.

New Window Options

When replacing old windows, homeowners have many options for new window materials and styles. The most common types of replacement windows include:


Vinyl windows like those from Jeld-Wen are inexpensive, energy efficient, and durable. Vinyl frames don’t require painting and resist rot, corrosion, and insects. However, vinyl can become brittle and crack over time, especially in extreme weather. Vinyl also provides less insulation than other materials.


Wood windows made from pine, oak, and other hardwoods provide superior insulation. Wood offers a classic, aesthetically pleasing look. However, wood requires frequent repainting or staining to prevent rot and decay. It’s also prone to swelling and sticking if not properly maintained.


Fiberglass windows rival wood in appearance while avoiding some downsides like rotting. Fiberglass is durable, energy efficient, and low maintenance. It resists shrinking, swelling, and warping. But fiberglass can be prone to scratches and is typically more expensive than vinyl.

Aluminum and Aluminum Clad

As Lowe’s notes, aluminum windows are affordable, durable, and lightweight yet strong. Aluminum conducts heat rapidly, so insulation may be lacking. Aluminum clad windows add a vinyl or composite overlay for better insulation and aesthetics.


Composite windows from recycled wood, vinyl, and other materials provide durability and energy efficiency. Composites resist rot, cracking, and insects. They offer extensive design flexibility. But composites can be expensive and some composite materials lack strength.

Installation Process

The process of replacing windows involves multiple steps. As outlined on This Old House [1], the first step is to gather the replacement window parts needed, including the new window, shims, sealant, flashing, fasteners, pry bar, and caulk. The next step is to accurately measure the opening and purchase a replacement window of the proper size. Removing the old window involves prying off trim pieces, sill, and jamb liners to expose the window frame. The frame is prepped by cleaning, scraping, and sealing. The new window can then be centered in the frame opening and shimmed into place. It should be checked for level and plumb. The window can then be secured into the frame with fasteners applied through the nailing flanges. Finally, the installer will seal gaps, add exterior flashing, install interior stop molding, and add trim pieces like the stool and apron. Regular caulking and painting finishes the job.

As summarized on Lowes [2], key steps are cleaning the window opening, applying flashing tape, verifying the sill is level, dry fitting the new window, applying caulk around the perimeter, shimming the window into place, fastening through the nailing flanges, checking operation, insulating gaps, and sealing the exterior. The installer may need to extend or modify interior and exterior trim pieces for a clean finished look.

In summary, the full window replacement process requires careful measurement, frame preparation, proper shimming and installation of the new window unit, sealing interior and exterior gaps, and finishing with trim, caulk, and paint. Homeowners should expect a process that takes patience and care to ensure the window operates smoothly and prevents air and water infiltration.

Finding a Reliable Contractor

When hiring a contractor to replace your home’s windows, it’s important to find someone qualified and reliable. According to Angi, start by asking neighbors, friends and family for referrals of contractors they were satisfied with. You can also check sites like Angi and HomeAdvisor for local contractors with positive reviews. When reaching out to potential contractors, ask how long they’ve been in business, what brands of windows they use, and if they have a showroom. Also inquire about their licensing, insurance and warranty policies.

Once you’ve identified a few reputable contractors, get written bids from each one. Make sure the bids are based on the same work specifications so you can accurately compare pricing. Ask the contractors detailed questions about their project timelines, materials, installation methods and post-project cleanup plans. Negotiate to get the best overall value, not just the lowest price. Require references from recent customers and follow up before making your final hiring decision. With some due diligence, you can find an experienced and fairly priced contractor.

Permit Requirements

Replacing windows often requires obtaining permits, especially if you are replacing a significant number of windows or all the windows in your home. According to the California Building Code and California Residential Code, permits are required for window replacements to ensure the work meets code requirements (source).

Permit requirements can vary by location. Some areas may require permits if more than a certain percentage of windows are being replaced, while others require permits for any window replacement. The purpose of permits is to have the work inspected to ensure proper installation according to building codes and safety standards.

The permit application process typically involves submitting window specifications, contractor information, and payment. Approved permits allow you to move forward with the window replacement work. Expect at least one inspection from the local building department during the process to check that the new windows meet code.

Obtaining proper permits protects homeowners and provides oversight for window replacement projects. Though permits add steps, costs, and inspection requirements, they help ensure the work is done safely, legally, and up to current building code standards (source).


In summary, there are several factors to consider when deciding if replacing 20 year old windows is worthwhile. The efficiency and maintenance needs of old windows, along with replacement costs and options should be evaluated. Key points include:

  • Older windows may be drafty and allow heat to escape, leading to higher energy bills. New windows with double or triple paning can improve insulation.
  • Old windows can be difficult to open and may not seal properly. New windows are easier to operate and maintain.
  • Replacing windows is a significant expense, but may pay off long-term in energy savings.
  • New vinyl, wood, or fiberglass windows offer improved durability and options like tinting.
  • Hiring a qualified contractor is recommended to ensure proper installation and avoid future issues.

In the end, weighing factors like window age, efficiency gains, and costs can determine if replacement is a smart investment for your home.

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