Frequently Asked Questions - Windows

Window FAQ's

Are new windows more likely to crack?

Stress cracks can sometimes appear in newly installed windows, but they are not necessarily related to the age or quality of the window itself. According to Pella engineers, stress cracks are often influenced as much by the architectural design and shading conditions of the home as by the glass in the window. Changes in sunlight exposure, temperature fluctuations and shading patterns can all contribute to thermal stress on the glass over time.

Can a stress crack in a window be repaired?

In some cases, a stress crack may be temporarily repaired using a glass repair solution designed to help limit the spread of the crack. However, because stress cracks are caused by ongoing expansion and contraction in the glass, the crack may continue to grow over time. Depending on the size, location and severity of the damage, replacing the glass or the entire window may be the best long-term solution.

Why did my window crack on its own?

Windows that crack without an obvious impact are often experiencing thermal stress cracks. These cracks develop when different areas of the glass heat up or cool down at uneven rates, causing the glass to expand and contract unevenly. This most commonly occurs when one portion of the window is exposed to direct sunlight while another remains shaded. Rapid seasonal temperature swings, large panes of glass and partial shading from trees or roof overhangs are some of the most common causes.

What is the difference between a casement and awning window for a kitchen?

Both casement and awning windows use crank mechanisms that make them easier to operate over a sink. Casement windows are hinged on the side and swing outward, while awning windows are hinged at the top and open outward from the bottom.

Why is there often a window over the kitchen sink?

Windows above kitchen sinks are a practical tradition because the space above the sink is often difficult to use for cabinetry and benefits from additional natural light. Historically, sinks were commonly placed on exterior walls for plumbing access, making windows above them a natural design choice.

What Causes Condensation Between Window Panes?

Condensation between panes occurs when the seal that holds the insulated glass unit together fails, allowing moisture to enter the space between the glass. Once the seal is broken, it cannot be effectively repaired — the window or insulated glass unit typically needs to be replaced.

How Do I Know If My Windows Are Drafty?

Close and lock your window, then hold your hand near the frame edges and corners. If you feel air movement, you have a draft. Alternatively, hold a lit candle or incense stick near the frame — if the flame or smoke wavers, air is leaking through. Drafty windows contribute to higher energy bills and reduced comfort.

What is the most energy-efficient type of window?

Picture windows are the most energy efficient because they do not open and form a complete seal. Among operable types, casement and awning windows seal more tightly than double-hung windows.

What percentage of home energy loss comes from windows?

Heat gain and heat loss through windows account for 25–30% of residential heating and cooling energy use, according to the U.S. Department of Energy.

What is the best window frame material?

The best frame material depends on your priorities. Fiberglass offers exceptional durability, vinyl balances value and efficiency, and wood provides timeless beauty with strong insulation.

Is vinyl always the cheapest window material?

Vinyl is often considered a value-focused option because it typically offers an accessible starting price point and low maintenance requirements. However, project costs can vary based on window size, style, glass packages and installation complexity.

Which window material lasts the longest?

Longevity varies based on climate, installation quality and maintenance. Each material is designed to perform well when properly specified and cared for.

Why is wood more expensive than vinyl?

Wood typically involves higher material costs and greater customization, which increases manufacturing and finishing requirements compared to vinyl.

Does my home’s age affect replacement cost?

It can. Older homes may require more detailed labor to handle delicate trim or to address hidden issues like frame rot that only become visible during the replacement process.

Why do two window quotes differ so much?

Quotes vary because they reflect different choices in glass, installation methods, and the thoroughness of the work required to protect your home’s structure.

Why does replacing many windows cost more than the sum of the parts?

Beyond the products, replacement projects can involve complex installation requirements, regional labor rates, and the specific condition of your home's exterior and interior.

Are cheaper windows worth it?

Lower-cost options may suit some projects, but durability, comfort and maintenance should be considered alongside upfront price.

Is it cheaper to replace all windows at once?

Replacing multiple windows together can streamline installation, but total cost still depends on window size, type and configuration.

Do bay and bow windows increase home value?

Yes, both styles can enhance curb appeal, improve natural lighting, and increase resale value.

Which is better, a bay or bow window?

It depends on your needs. Bay windows are ideal for more defined, angular spaces and ventilation, while bow windows provide a softer, rounded appearance with more natural light.

What are the best windows to keep heat and cold out?

Double- or triple-pane windows with Low-E glass and argon gas fills provide excellent insulation, helping keep your home comfortable year-round by reducing heat loss in winter and heat gain in summer.

Are bow windows energy efficient?

Absolutely. Modern bow windows often feature insulated frames and advanced glass options that help reduce heat transfer.

Do bow windows add value to a home?

Yes. Bow windows can enhance curb appeal, increase natural light, and help boost resale value.

What is the average cost of a garden window?

On average, garden windows cost more than a single window replacement. Typically, homeowners will need to buy or replace one or more windows at a time. Garden windows will cost between $1,000 – $5,000 depending on the window types and customizations.

What is the key difference between a garden window and a bay window?

A garden window can be built from a variety of window types including but not limited to bay windows, bow windows, picture windows and even awning windows. Bay windows are made up of three windows that project outwards from an exterior wall. This window type can use picture, casement, double- and single-hung windows to create its look.

What are curved windows called?

Curved windows are also referred to as arched windows. This window style uses a curved top frame and a square or rectangular bottom frame.

Are arched windows more expensive?

Yes, arched windows are typically more expensive because they are customized by the client. This makes them more expensive, up to $50-100 more per window. Homeowners can purchase arched windows from Pella either scheduling an in-home consultation or visiting a local showroom.

What is the difference between a bay and bow window?

The primary differences between bay and bow windows are the number of windows used and the architectural design of each style. Bay windows typically consist of three windows and angular lines, while bow windows use four or more windows to create a gentle curve on your home’s exterior.

What is a Queen Anne window?

A Queen Anne window is a type of decorative window popular during the later Victorian period, particularly within Queen Anne-style architecture. These windows often combine clear and colored glass and may feature a small pane of stained or leaded glass at the top of a larger, clear-glass sash. The effect is both artistic and light-enhancing, adding a focal point to a room or façade.

How narrow can a casement window be?

The practical minimum width may depend on the specific manufacturer and the hardware used. Extremely narrow windows might limit the amount of light and ventilation, so the choice should balance these factors with the architectural design.

What is the minimum size for an egress window in a casement?

Casement windows are a great choice for meeting egress requirements and are commonly used in bedrooms due to their larger openings, which provide easier escape access. Egress requirements can vary based on material types and local building codes, so it’s best to consult your window professional to ensure compliance and proper sizing for your specific needs.

Should window trim match door trim?

While window trim doesn't have to match door trim exactly, they should complement each other for a cohesive look. Most designers recommend keeping trim styles consistent within the same room or on the same floor of your home.

What is the rule for window casings?

The general rule for window casings is that they should:

Be proportional to the window size (typically 2.5" to 3.5" wide for standard windows)
Match or complement other trim work in the home
Be consistent throughout the same floor or room
Have mitered corners for a professional appearance

What kind of trim goes around windows?

Window trim, also called casing, typically consists of several parts:

Side casings that run vertically along each side
Head casing across the top
Sill and apron at the bottom
Sometimes additional decorative elements like rosettes or crown molding

What is the most important factor when choosing window glass?

While energy efficiency is crucial, the most important factor is matching the glass type to your specific needs. Consider your climate, security requirements and budget to make the best choice.

Which glass should be used for windows?

For most residential applications, double-pane glass with Low-E coating is recommended. This provides good energy efficiency and comfort. However, specific needs might call for tempered glass in safety areas or laminated glass for sound reduction.

Are there energy-efficient updates for mid-century windows and doors?

Absolutely. Modern solutions like double-glazed or triple-glazed windows can enhance insulation and lower energy costs. Low-emissivity (Low-E) coatings on glass help regulate heat transfer, and frames made from materials like fiberglass or advanced composites offer improved thermal performance. These options allow you to maintain the mid-century aesthetic while upgrading your home’s energy efficiency.

Why are large windows such a key feature in mid-century modern homes?

Large windows are essential in mid-century modern design because they reflect the era’s focus on integrating with nature. These expansive windows flood interiors with natural light, reduce dependence on artificial lighting, and offer uninterrupted views of the surrounding landscape. Their design aligns with the philosophy of openness, simplicity, and harmony with the environment.

What materials are typically used for windows and doors in mid-century homes?

Windows and doors in mid-century homes often feature materials like aluminum, steel, and wood. Aluminum and steel provide a sleek, modern look with minimal maintenance, while wood introduces warmth and versatility to the design. These materials contribute to the clean lines and functional beauty that are hallmarks of mid-century architecture.

What types of homes are best suited for prairie style windows?

Homes that embody contemporary, farmhouse or geometric architectural styles are best suited for prairie style windows. These windows enhance the visual appeal of structures that emphasize straight lines and angles, making them ideal for homes that aim to blend traditional elegance with modern design trends.

Are prairie windows energy efficient?

Yes, many prairie windows are available with energy-efficient glass and frames, helping you reduce heating and cooling costs.

What is the difference between prairie style windows and other window types?

Prairie windows feature distinctive grille patterns along the perimeter of the glass, creating a geometric look. Other window styles may use different grille configurations or lack them entirely.

What is a defining feature of Victorian era interior design?

Victorian interior design is defined by its opulence and intricate details. Homes often featured rich, dark color schemes, heavy fabrics like velvet and brocade, and elaborate furniture pieces. Walls were frequently decorated with patterned wallpapers, while rooms were adorned with decorative objects such as ornate lamps, vases and artworks. Dark woodwork, detailed moldings and ceiling medallions added to the luxurious and layered aesthetic.

Why do Victorian houses have high ceilings?

High ceilings in Victorian houses were both a practical and stylistic choice. Architecturally, they reflected the era’s emphasis on grandeur and opulence. Practically, they helped improve air circulation in the absence of modern air conditioning, allowing hot air to rise and keeping living spaces cooler in warmer months.

How do I identify a Victorian house?

Victorian houses are recognizable by their distinctive architectural details, such as intricate trim, asymmetrical designs, steeply pitched roofs and the inclusion of towers or turrets. These homes often feature expansive, ornate porches, patterned shingles or brickwork and vibrant exterior color schemes. Inside, they showcase high ceilings, elaborate moldings, stained glass windows and a mix of styles and decorative elements that define Victorian architecture.

How do I balance light and privacy in my cottage home?

Choose smaller windows for intimate spaces like bathrooms or bedrooms. For larger windows, opt for frosted glass or interior window treatments like curtains or blinds.

What exterior treatments complement cottage windows?

Board and batten shutters, raised-panel shutters and flower-filled window boxes add the finishing touches to cottage-style windows.

What window styles best suit a cottage home?

Double-hung and casement windows with grille detailing, arched windows and bay or bow windows are ideal for cottage homes.

How do I choose the right windows for my home’s architectural style?

Modern homes benefit from clean, sleek designs like stacked awning windows or large picture windows. Traditional styles, such as Victorian or cottage, often look best with smaller windows, grilles or decorative shapes. Observe your home’s structure from the curb for inspiration.

What are dormer windows, and are they a good option for my home?

A dormer is a small structure that projects out from the sloped roof of a home. For those wanting to finish an attic into livable square footage, dormers maximize usable space by adding headroom, natural light and airflow in these previously small and underutilized rooms. Dormer windows are known for their distinct roof shapes and styles including gabled, shed, hipped and eyebrow.

What types of windows are best for maximizing natural light?

Large picture windows are excellent for maximizing natural light. These windows provide expansive views and flood your home with sunlight, making them ideal for rooms like sunrooms, living rooms or bonus spaces.

Can I replace a bow window with a bay window?

The structural differences may require adjustments to your framing or exterior siding. Consulting with a professional is advisable to ensure a proper fit and to address any potential changes needed for insulation, drainage or architectural compatibility.

What style homes have bay windows?

Bay windows are a versatile architectural feature that can enhance a variety of home styles. They are commonly found in traditional, Victorian, colonial, craftsman and farmhouse homes, where they add character and elegance to the design.

Are bay windows still in style?

What are the benefits of a bay window?

Bay windows can increase your living space by providing you with an area to create a reading nook, additional seating or even a display shelf. The large window configuration also provides increased natural light to your home, making the space feel larger and more open. Bay windows also add curb appeal by creating a stylish architectural statement on the exterior of your home.

Do bay windows increase home value?

Yes, bay windows can increase home value by adding both aesthetic appeal and functional space. Their classic design creates a focal point that helps enhance curb appeal, while the extra light and added interior space make rooms feel larger and more inviting. This combination of beauty and functionality can attract potential buyers and positively impact resale value.

What is the difference between dual- and triple-pane windows?

Dual-pane windows have two panes of insulating glass, while triple-pane windows have three panes of insulating glass. As more panes of glass are added, windows generally become more energy efficient. Triple-pane products also feature a hinged glass panel to access between-the-glass blinds and shades. Learn more about double- and triple-pane windows.

When to install windows?

Windows can be installed any time during the year, including winter. Spring is the busy season, but window installation is not necessarily a seasonal project. If your windows need replaced, there’s no need to wait for warmer weather. Pella professionals install one window at a time and take extra precautions to ensure your home stays warm and comfortable during winter installs.

Are mulls available to put multiple windows together?

Yes, at Pella, this process usually takes place in the factory, meaning the combined units conveniently ship to you as one piece, ready to be installed. Shop our selection of multi-wide mulled windows online or schedule an in-home consultation.

What is a left vs. right venting casement window?

Viewing from outside the home, a left-venting casement window has hinges on the left side. From inside the home, hinges are on the right side. Viewing from outside the home, a right-venting casement window has hinges on the right side. From inside the home, hinges are on the left side.

What are the benefits of fiberglass windows?

Pella’s proprietary fiberglass is the strongest material for windows, engineered for lasting durability.⁹

Are sliding windows efficient?

Yes, sliding windows, available in fiberglass and vinyl, offer enhanced energy efficiency. These designs have an interlocking system where the sashes come together to create a tight air seal.

Are double-hung windows more efficient than single-hung windows?

Single-hung windows are typically more energy efficient than double-hung windows because one of the sashes is sealed and stationary.

Are Encompass windows energy efficient?

Yes, Pella's exclusive weather protection system helps protect a home from leaks and drafts. Encompass by Pella windows offer solutions that will meet or exceed ENERGY STAR® guidelines in all 50 states.¹

Can picture windows be opened?

No, picture windows have fixed frames and do not operate.

Are sliding windows energy efficient?

Yes, most sliding windows are energy efficient. Energy efficiency is dependent on a number of factors including the material of the window, the type of glass and the number of moving parts.

Why should I use single-hung windows?

Because only one sash is moveable on a single-hung windows, they are great for homeowners who are looking for potential cost savings replacing multiple windows and for replacement on the first floor of a home. Single-hung windows can be slightly more efficient than double-hung windows, as there are fewer moving parts which reduces the opportunity for air infiltration. To learn more about what makes single-hung windows unique, check out this article.

How do I clean a double-hung window?

When cleaning double-hung windows, tilting the sashes in makes it easy to clean exterior surfaces from the interior of your home. Clean the top sash first, starting with the exterior and followed by the interior, and then repeat the same process on the lower sash. Watch this step-by-step video to learn more about window washing for easy-clean double-hung windows.

Do casement windows have screens?

Yes, casement windows can be ordered with screens on the inside where they're protected from the elements.

How do you measure for replacement windows?

When it comes to measuring your windows for replacement, remember to measure the product width and height. Follow these instructions on how to measure windows and get the most accurate dimensions.

What are double paned windows?

Double-pane windows, also referred to as dual-pane or double-glazed windows, have two panes of glass, many with insulating argon gas between the panes. The additional layer of material, plus the insulating gap in between is what makes them stand out. Double-pane windows help reduce sound and improve energy efficiency.

What are transom windows?

Transoms are stationary sections of glass placed above an entry door and its sidelights. They allow natural light to stream into your entryway.

What are sash windows?

The sash is the moveable part of a window made up of the vertical and horizontal frame that holds the glass. Single-hung windows are also known as single-sash windows, while double-hung windows are commonly referred to as double-sash windows. Learn more about the differences between single-hung and double-hung windows.

What are Low-E windows?

Low-E, or low-emissivity, glass minimizes the infrared and ultraviolet light that comes through your glass, without greatly reducing the amount of light that enters your home. Therefore, Low-E glass is more energy efficient and helps to protect your furniture and flooring from fading.

What is the difference between a bay and bow window?

The main difference between bay and bow windows lies in the number of windows each has. Bay windows consist of three windows, typically two angled operable windows with one fixed inoperable picture window between. Bow windows are comprised of four or more windows of the same size and shape to create a more subtle curve than a bay window. To explore more of the differences between bay and bow windows, check out this article.

What are the best replacement windows?

There are a number of factors at play when you’re shopping for replacement windows for your home. In addition to a window that enhances the beauty and energy efficiency of your home, you want a window that suits your lifestyle and your budget. As you start shopping, check out this article that helps you focus your window search and find the windows that are right for your project.

What is a new construction window?

New construction windows are primarily made for newly built homes or other new construction such as commercial buildings or a home addition. Installation of a new construction window requires that studs are exposed.

What is the most affordable window?

In general, Pella's vinyl windows are more budget friendly than fiberglass or wood windows. Of the vinyl window product lines, Encompass by Pella® is the most affordable.

Are fiberglass windows efficient?

Yes, Pella's fiberglass window frames have virtually no expansion and contraction to help improve energy efficiency, reduce the risk for seal failure and provide long-term stability for dependable operation. In addition to the material of the window frame, glass types and coatings also affect the energy efficiency of a window.

Are fiberglass windows better than vinyl?

It depends what benefits are most important to you. Pella's fiberglass is the strongest material for windows, offering a low-maintenance and durable finish.⁹ If you're after a window that's tested to extremes, Pella's fiberglass windows are the way to go. Vinyl windows are easy to care for, energy efficient and budget friendly. Pella’s unique vinyl formula is performance-tested for excellent weathering, durability and color retention.

What product lines are made of wood?

Pella offers the following product lines made of wood: Pella® Reserve™ - Traditional, Pella® Reserve™ - Contemporary and Pella® Lifestyle Series. These product lines feature windows and patio doors. There are also many front entry doors available in wood.

How long do wood windows last?

It depends. There are many factors that affect the long-term performance, appearance and functionality of wood windows. Adding aluminum cladding to the exterior will help protect wood windows from the elements for years to come.

What is the most efficient window?

Picture windows are extremely energy efficient given that they do not open and close. Also highly efficient are windows with dual- and triple-pane glass as they improve insulating properties and help reduce thermal transfer.

How do awning windows open?

Awning windows are hinged at the top and swing out from the bottom with the simple crank of a handle or with the Easy-Slide Operator hardware.

How do single-hung windows open?

Single-hung windows have a fixed sash on top with a bottom sash that slides up and down to open and close the window.

How do casement windows open?

Casement windows are hinged on either the left or right side, swinging open and close with Pella's patent-pending Easy-Slide Operator or an easy-to-use crank that folds away when not in use.

Should I replace my windows all at once?

It depends on why you are replacing windows. If a window is not functioning properly or is broken, it might be best to replace only that window. If you are looking to improve your home’s energy efficiency, update the entire look or reduce noise, replacing your windows all at once will likely achieve those goals more quickly and cost-effectively.

What is the difference between single-hung and double-hung windows?

The difference between single-hung and double-hung windows is the number of sashes that move. A single-hung window has one fixed, or non-operable, sash and one operable, or moveable, sash. A double-hung window has two operable, or moveable, sashes.

Are floor-to-ceiling windows expensive?

We offer several product lines made from a variety of materials that can meet your home’s style and budget needs. The final price will depend on the materials, features and options that you choose.

What are floor-to-ceiling windows called?

Floor-to-ceiling windows are commonly referred to as window walls. They are a combination of large windows that give the appearance of a wall of glass.

What are the benefits of replacing my windows?

Energy efficiency, reduced noise and curb appeal are among the key benefits of replacement windows.

If I install the product myself does it void the warranty?

No, if Pella’s installation instructions are followed, your product is covered by the product warranty. See our installation instructions here.

How do I identify a thermal stress crack?

Thermal stress cracks are often identifiable because they begin at the edge of the glass and extend inward at a perpendicular angle. According to Pella customer support representative Faye Howard, the crack will typically run straight from the glass edge for about a half-inch before it may begin to spider in other directions. In some cases, cladding or trim may make the edge of the glass difficult to see.

What are the three types of window cracks?

Pella engineers recognize three general types of window cracks: thermal stress cracks, impact cracks and pressure cracks. Thermal stress cracks typically begin at the edge of the glass and form at a perpendicular angle due to sudden temperature swings or shading changes. Impact cracks create a starburst pattern that radiates outward from a central point after the glass is struck. Pressure cracks resemble the curve of an hourglass and can occur in insulating glass windows when there are significant elevation differences or drastic pressure changes in the weather.

Are bay windows good for kitchens?

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