Wondering how to choose the top-rated energy efficient windows and the best replacement windows available in the market today? We’ll delve into the features that make these windows stand out, helping you make an informed decision for your new home build or home improvement project.

Today’s homeowners are increasingly focused on energy efficiency and sustainability. One of the most effective ways to improve your home’s energy performance is by investing in high-quality, energy-efficient windows. Whether you’re building a new home or looking to upgrade your existing windows, choosing the right energy-efficient and replacement windows can significantly impact your home’s comfort, aesthetics, and energy bills.

Next up in our green and energy-efficient home building series, is the topic of windows. Other posts you will want to read include:

• Why You Should Consider an Eco-friendly Passive House?
• 7 Reasons Metal Roofing is a Great Option for Your Home
• 6 Ways to Use Eco-Friendly Plumbing Solutions at Home

How to Choose the Best Top Rated Energy Efficient Windows

But with so many window manufacturers and options on the market, how do you navigate the sea of choices to find the perfect energy saver windows for your home? Let’s dive into the key factors you need to consider before taking the plunge. Energy-efficient windows aren’t just a fancy upgrade — they’re a smart investment that can significantly impact your home’s comfort and your monthly energy bills.

Understanding Window Efficiency Ratings

Before you start window shopping, it’s important to understand what makes a window energy efficient. Take a look at the picture above which include the ratings for the windows installed in our Passive House. Energy efficiency in windows is primarily measured by these ratings.

U-Factor

A window’s U-Factor measures how well a window insulates. The lower the U-factor, the better the window is at keeping heat inside during winter and outside during summer.

Solar Heat Gain Coefficient (SHGC)

A window’s solar heat gain coefficient indicates how much solar radiation passes through the window. In hot climates, a lower SHGC is preferable to keep your home cooler.

Visible Transmittance (VT)

A window’s VT measures how much natural light the window allows into your home. Higher VT means more daylight, which can reduce the need for artificial lighting.

Air Leakage (AL)

A window’s air leakage rating tells you how much air can enter through the window. Lower AL means fewer drafts and better insulation.

Key Features of Energy-Efficient Windows Include

• Multiple panes (double or triple-glazing)
• Low-E (low-emissivity) coatings
• Gas fills between panes (usually argon or krypton)
• Warm edge spacers
• Quality frame materials (vinyl, fiberglass, or wood-clad)

When you’re looking for top rated energy efficient windows, make sure they’re ENERGY STAR certified. That means they meet strict energy efficiency guidelines set by the U.S. Environmental Protection Agency and the Department of Energy.

You Window Frame Materials Matter

You might not know this, but the window frame material plays a significant role in its energy efficiency and durability too. Common window frame materials include:

Vinyl

Vinyl windows are often affordable, low-maintenance, and good insulators. However, they may not be as aesthetically pleasing as other options.

Wood

Excellent insulators with a classic look, but require more maintenance and can be prone to warping or rotting if not properly cared for.

Fiberglass

Durable, low-maintenance, and excellent insulators. They can also be painted to match your home’s aesthetic.

Aluminum

Aluminum Windows are sturdy and low-maintenance, but not as energy-efficient as other options due to high heat conductivity.

Composite

Composite windows are made from a mix of materials, these frames offer good insulation and durability with less maintenance than wood.

When you’re choosing the best replacement windows, make sure to consider your climate, budget, and home’s architectural style when choosing frame materials too.

Glass Options and Technologies

The part of your window where the energy saving magic happens is the glass. You might not realize there are so many options when it comes to the glass in your widows, but here are some window materials and technologies to consider.

Choose Double or Triple-Pane Windows Instead of Single Pane Windows

Multiple panes of glass with air or gas fill between them provide better insulation than single-pane windows.

Look for a Low-E Coating

These microscopically thin, transparent layers reflect heat while allowing light to pass through, improving both insulation and UV protection. When shopping for energy-efficient windows, look for Low-E coatings as a key feature. They’re an essential component in maximizing your windows’ thermal performance and overall energy efficiency.

Understand Gas Fills in Windows

Gas fills are used to improve the insulation properties of windows with multiple panes. The space between the glass panes is filled with a gas that’s denser than air which means they slow heat transfer between the interior and exterior of your home. Argon or krypton gas are the two most common types of gas used to make windows more energy efficient.

Warm Edge Spacers

Warm edge spacers are the parts that separate and seal the panes of glass in multi-pane windows. They maintain the gap between glass panes, provide structural support, and create a barrier to prevent moisture and gas leakage.

In a nutshell, warm edge spacers reduce heat transfer around the window’s edges, improving overall insulation and energy efficiency.

Climate Considerations

Your local climate should heavily influence your window choices. In colder regions, focus on a low U-factor to keep heat inside.

In warmer areas, prioritize a low SHGC to block out heat. If you live in an area with varied seasons, look for windows that balance both factors.

Window Installation: A Critical Factor

Even the most energy-efficient windows won’t perform well if they’re not installed correctly. Poor installation can lead to air leaks, moisture problems, and reduced efficiency.

Always work with certified professionals who have experience installing the specific type of windows you’ve chosen.

Style and Functionality

While energy efficiency is crucial, don’t forget about style and functionality. Consider how different window styles (e.g., double-hung, casement, awning) can complement your home’s architecture and meet your ventilation needs.

Some styles, like casement windows, tend to have better air sealing when closed, potentially increasing energy efficiency. Your best replacement windows are probably going to be different from your neighbor’s. And that is ok!

Return on Investment

Energy-efficient windows come with a higher upfront cost, but they can lead to significant savings over time. Calculate the potential energy savings based on your existing windows and energy costs. Many utility companies offer online calculators or can provide estimates to help you determine your potential return on investment.

Check for federal, state, or local incentives for installing energy-efficient windows. These can include tax credits, rebates, or low-interest loans that can help offset the initial cost.

As you make your decision, think long-term. Choose windows that not only meet your current needs but will continue to perform well and look good for years to come. Consider factors like durability, window warranty, and the window brand’s reputation.

Top-rated energy efficient American windows brands include: Pella, Marvin, and Anderson. Then windows in our passive house are a European brand called Shucco.

Whole-House Approach

While upgrading your windows can make a big difference, it’s important to consider your home’s overall energy efficiency. Combining the best replacement windows with a durable and energy efficient roof, proper insulation, sealing air leaks, and upgrading your HVAC system can maximize your energy savings and home comfort.