Windows for energy-efficient houses: How to choose the right solutions

With rising energy costs and increasing environmental concerns, more people are opting to build energy-efficient homes. Globally, there is a noticeable trend towards sustainable construction. Energy-efficient homes, through the use of modern technologies and materials, minimize energy consumption, leading to lower utility bills and reduced environmental impact.

In the context of building energy-efficient homes, windows play a crucial role in their energy performance. Properly selected and installed windows can significantly reduce heat loss in winter and prevent excessive heat gain in summer. Thus, choosing the right windows not only enhances the living comfort of the residents but also affects the overall maintenance costs of the home. This article aims to provide insights into selecting suitable windows for energy-efficient homes and offers practical information and tips to help make informed decisions.

Trends in the energy-efficient construction market

Growing popularity of energy-efficient buildings in recent years

In recent years, the market for energy-efficient construction has been growing rapidly. More and more people are opting to build homes characterized by low energy consumption. According to data collected by the National Association of Home Builders (NAHB), in 2023, about 30% of new single-family homes met energy efficiency criteria. This is a significant increase compared to 2010, when only 10% of new buildings had such properties.

Future Predictions for the Green Building Market

Forecasts indicate that this trend will continue to grow. It is anticipated that by 2030, over 50% of newly constructed homes will feature high energy efficiency. This growth is driven by evolving building regulations increasingly incorporating energy efficiency standards and a rising public awareness of environmental issues.

Factors driving the growing interest in energy-efficient solutions

Rising Energy Costs

One of the main factors motivating people to invest in energy-efficient homes is the rise in energy costs. Over the past two decades, the prices of electricity and natural gas have steadily increased. For many families, monthly energy bills constitute a significant portion of the household budget. Energy-efficient homes, which consume less energy, can substantially reduce these costs, making them a compelling choice.

Environmental Awareness

Alongside rising energy costs, environmental awareness is also growing. Many people want to actively contribute to environmental protection, and building an energy-efficient home is a concrete step in that direction. Such homes not only use less energy but also often incorporate renewable energy sources like solar panels.

Government Support and Tax Incentives

A crucial factor supporting the development of the energy-efficient construction market is the various forms of government support. Both federal and state levels offer numerous funding programs and tax incentives for those investing in energy-efficient technologies. For instance, the federal tax credit allows for a 30% deduction on the cost of installing solar panels. Additionally, many states provide further financial incentives, further reducing the investment costs in energy-efficient solutions.

These factors contribute to the increasing popularity of energy-efficient construction, leading more people to build homes that are not only environmentally friendly but also more economical to maintain.

The role of windows in energy-efficient houses

How windows affect a building’s energy efficiency?

Heat loss through windows

One of the main issues with windows is heat loss. During winter, when the temperature difference between the inside of the home and the outside is greatest, a significant amount of heat can escape through the windows.

Traditional, older window models often have low insulation properties, resulting in considerable heat loss. This practically means higher heating bills and reduced thermal comfort inside.

Solar heat gains

Conversely, windows can also contribute to heat gains through solar radiation. Sunlight passing through the glass can warm the interior of a building, which is particularly beneficial in cooler climates.

However, excessive sunlight in the summer can lead to overheating of the rooms, increasing the need for air conditioning. Therefore, it is important that windows are designed and positioned to maximize heat gains in winter and minimize them in summer.

Window Parameters Essential for Energy Efficiency

For windows to effectively support a building’s energy efficiency, they must meet specific technical parameters. The most important of these are the U-value (heat transfer coefficient), solar heat gain coefficient (SHGC), and visible transmittance (VT).


The U-value measures how well a window retains heat inside a building. The lower the U-value, the better the window’s insulation properties. In practice, this means that a window with a low U-value will more effectively prevent heat loss in winter and reduce interior overheating in summer. In modern, energy-efficient windows, the U-value is usually below 1.0 W/m²K.

Solar Heat Gain Coefficient

The SHGC determines the portion of solar energy that passes through a window into the building. A high SHGC means the window allows more solar energy to enter, which is beneficial in winter as it additionally heats the interior. In summer, however, windows with low SHGC are preferred to limit room heating. The choice of the appropriate SHGC depends on the climate and the building’s orientation relative to the sun.

Visible Transmittance

VT indicates the fraction of visible light that passes through a window. A higher VT means more natural light enters the interior, which can improve the residents’ quality of life and reduce the need for artificial lighting. However, excessively high VT can lead to overheating of rooms in summer, so it’s important to find the right balance.

Passive House Design

Types of windows for energy-efficient houses

Double-glazed windows

Better thermal insulation: Double-glazed windows significantly better insulate heat than single-glazed ones, thanks to the space filled with air or gas between the panes.

Noise reduction: Double-glazed constructions better isolate external sounds, improving interior acoustical comfort.

Higher cost: They are more expensive than single-glazed windows, which may be a barrier for some investors.

Greater weight: They may require stronger frames and a more solid building structure.

Triple-glazed windows

Best thermal insulation: Triple-glazed windows offer the highest level of thermal insulation, minimizing heat loss.

Excellent sound insulation: Three glass layers effectively dampen external sounds, providing a quieter interior.

Energy savings: Higher energy efficiency translates into lower heating and cooling costs for the home.

Higher cost: Triple-glazed windows are a more expensive option than double-glazed ones, but they certainly represent a good investment.

Modern technologies in energy-efficient window production

Low-E Coatings

  • Better insulation: Low-E coatings reflect thermal radiation, helping to retain heat inside the building in winter and reduce interior heating in summer.
  • Energy savings: They reduce the need for heating and air conditioning, resulting in lower energy bills.
  • Higher cost: Windows with Low-E coatings are more expensive than standard ones, but this investment pays off in energy savings.

Gas Fillings

  • Better insulation: Gases such as argon or krypton have better insulation properties than air, reducing heat loss through the window.
  • Improved energy efficiency: Gas fillings significantly increase the energy efficiency of windows, leading to lower heating and cooling costs.
  • Higher cost: Windows with gas fillings are more expensive to produce, which affects their market price.

Choosing the right windows for an energy-efficient home is a crucial element that significantly impacts thermal comfort, operating costs, and the building’s environmental friendliness. Understanding the differences between available options will help make an informed decision that brings long-term benefits.

How to encourage purchasing windows with enhanced thermal insulation parameters?

Savings on energy

Bills One of the key arguments for investing in windows with enhanced thermal insulation parameters is the savings on energy bills. Energy-efficient windows significantly reduce heat loss in winter and decrease the need for air conditioning in summer. In practice, this means users can expect significant reductions in heating and cooling costs. Although investing in high-quality windows may initially entail higher expenses, it pays off through lower energy bills.

Increase in property value

Homes equipped with energy-efficient windows are more attractive in the real estate market. Potential buyers increasingly pay attention to aspects related to the energy efficiency of buildings, which translates into a higher market value for such properties. Investing in modern, energy-efficient windows can not only bring savings in daily home operation but also increase its value when sold.

User comfort improved sound insulation

Windows with enhanced thermal insulation parameters typically also offer better sound insulation. This effectively dampens external noises such as street traffic or sounds from neighboring houses, contributing to higher living comfort by creating a quieter and more peaceful interior.

Increased thermal comfort inside the building

Energy-efficient windows also provide better thermal comfort. In winter, they help retain heat inside the building, while in summer, they reduce room heating. This ensures a more stable temperature inside the home, enhancing daily living comfort. Smaller temperature fluctuations also result in less strain on heating and cooling systems, further prolonging their lifespan.

Available financial support programs and tax credits federal and state financing programs

Various financial support programs are available to promote investments in energy-efficient technologies. Federal programs, such as Energy Star, offer various forms of support, including grants and loans with favorable terms for homeowners upgrading their homes. Many states also have their own programs that further encourage investments in energy-efficient solutions, including windows with enhanced thermal insulation parameters.

Tax credits for energy-efficient upgrades

In addition to direct financing programs, various tax credits are available, significantly reducing the costs of investing in energy-efficient windows. Federal tax credits allow for deducting a portion of the costs of purchasing energy-efficient window installations from income tax. Many states also offer their own tax credits, which may vary depending on local regulations and programs.

Investing in windows with enhanced thermal insulation parameters brings a range of economic, environmental, and user benefits. The availability of financial support programs and tax credits further enhances the attractiveness of such investments. Therefore, it’s worth considering replacing old windows with modern solutions that not only improve quality of life but also contribute to environmental protection and financial savings.

Practical tips for choosing and installing windows

Energy labels are a key source of information when choosing windows for an energy-efficient home. They contain detailed data on thermal parameters and other window properties. What should you pay attention to?

NFRC certification for Imperial Tilt Turn Window demonstrating energy efficiency
NFRC Neo Tilt Turn
NFRC certification for Genesis Tilt Turn Window showing energy efficiency
U-Value (Heat Transfer Coefficient)

Definition: Measures how well a window prevents heat loss from the home’s interior.

Ideal value: For energy-efficient windows, the U-value should be as low as possible, preferably below 1.0 W/m²K.

Solar Heat Gain Coefficient (SHGC)

Definition: Determines how much solar energy passes through a window. A higher SHGC means more heat enters the interior.

Ideal value: Depending on the climate – in cooler regions, a higher SHGC may be beneficial, while in warmer areas, a lower.

Visible Transmittance (VT)

Definition: Measures how much visible light penetrates through a window. A higher VT means brighter interiors.

Ideal value: Chosen according to the lighting needs of the rooms and residents’ preferences.

Condensation Resistance (CR)

Definition: Condensation Resistance assesses the window’s ability to prevent condensation of water vapor on its surface.

Ideal value: A higher CR value indicates better performance in preventing condensation.

Choosing the right manufacturer and professional installation


Recipe and experience: Choose manufacturers with a good reputation and extensive experience in producing energy-efficient windows.

Certificates and standards: Ensure that the manufacturer holds appropriate quality certificates, such as Energy Star or other national and international standards.

The Importance of professional window installation for efficiency

Professional window installation is as important as selecting the right products. Even the best windows won’t fulfill their functions if not properly installed. Precision during installation is crucial. Even small gaps can lead to significant heat loss and moisture penetration. Another aspect is proper sealing of the windows. This prevents air and water leaks, crucial for maintaining energy efficiency. Professional installation also involves using appropriate insulation materials around the windows, further enhancing their efficiency.

Energy-Efficient Home
Regular window maintenance

Cleaning: Regularly washing the glass and frames helps maintain their aesthetic appearance and ensures proper functioning. Avoid aggressive chemical agents that can damage low-emissivity coatings and seals.

Seal inspection: Regularly check the seals around the windows. Seals that begin to wear out or crack should be replaced immediately to prevent loss of insulation.

Lubrication of mechanisms: Window opening and closing mechanisms require periodic lubrication to operate smoothly and without disruptions.
Technical Inspections: Every few years, consider conducting a professional technical inspection of the windows to detect and repair any faults before they develop into more serious problems.

Taking care of the appropriate selection, installation, and maintenance of energy-efficient windows contributes to long-term savings, increased living comfort, and environmental protection. Thus, investing in modern windows brings benefits for many years.


Investing in windows with enhanced thermal insulation parameters is worthwhile due to numerous economic, environmental, and practical benefits. This investment leads to significant savings on energy bills and increases property value. Available financing support programs and tax credits further enhance the attractiveness of such investments. Investing in high-quality energy-efficient windows is a step that brings multidimensional benefits. Long-term financial savings, improved living comfort, and a positive impact on the environment make it a worthwhile decision.

Choosing the right windows is not only an investment in the future of your home but also a contribution to sustainable development and the protection of our planet. Therefore, it’s worth investing in windows with enhanced thermal insulation parameters to enjoy their benefits for many years.