Window size is one of the initial inquiries when you’re replacing old windows or constructing a new home. Many homeowners look up the window length to ensure that they choose a window of the size that will fit into the wall, looks aesthetically pleasing, and isn’t too expensive. The correct window size can impact the amount of natural light, ventilation, energy efficiency and even the resale value of your home.
In this blog post, the team of styleofhome.com will cover all the important details about common window sizes. This will help you decide wisely when you’re thinking about changing or adding new windows to your house.
What Does “Standard Window Length” Mean?
Standard Window length” may be a little confusing, as the word length is used in different ways. Window sizes are expressed in the window industry as width x height. There is no distinct measure that is length. The term window length is commonly used to refer to the height (the side of the window that is measured vertically) or the longer side.
A standard window length, thus is a common size window that is produced in the factory to fit a common rough opening in most homes. Manufacturers mass produce these dimensions, making them easier and quicker to purchase and install than custom sizes, and also less expensive.
The most popular window size for homes is 24″ X 36″, but they vary in size from the smallest 2′ X 3′ to the largest 8′ X 8′, depending on the window type and room size.
How Window Sizes Are Written
First, let’s explore the way manufacturers share their size prior to breaking down the dimensions. There are two systems in use.
The Width × Height Format
The simplest format. A 36 × 48 window is a window that is 36 inches wide and 48 inches tall. Width is always preferred, followed by height. Most quotes from a contractor and, showrooms and online catalogues use this format.
The Four-Digit Window Code
Manufacturers too often also utilize a four-digit code that combines the feet and inches. The first two numbers are width, the last two numbers are height. For example:
- 2030 = 2 feet 0 inches wide × 3 feet 0 inches tall (24″ × 36″)
- 2438 = 2 feet 4 inches wide × 3 feet 8 inches tall (28″ × 44″)
- 3040 = 3 feet 0 inches wide × 4 feet 0 inches tall (36″ × 48″)
- 4060 = 4 feet 0 inches wide × 6 feet 0 inches tall (48″ × 72″)
With the understanding of how to read the code, ordering the correct window becomes a lot easier.
Rough Opening vs Actual Window Size
If you are looking to select a window length, it is important to know the difference between the rough opening and the window unit itself.
Rough opening is the frame opening in the wall into which the window will fit. It includes the header at the top, the sill at the bottom and the studs on each side. The actual size of the window unit is always slightly smaller than the rough opening; typically, it is about ½ inch smaller on each side. This additional room provides the installer with space to level, insulate and seal the window properly for air and water.
For example, a window space that is marked for a 44 x 44 inch window will be approximately 43 ½ x 43 ½ inches. This small gap is necessary for proper and energy-efficient installation. Be sure to agree with your supplier if the size quoted is the rough opening or finished size.
Standard Window Lengths by Window Type
The size range for each window style is typical due to the size of the opening, the weight of the sash and the construction of the frame. The following are the most common standard lengths and widths of the most popular types of windows.
Double-Hung and Single-Hung Windows
There are 2 kinds of windows that are most commonly found in homes: double-hung and single-hung windows. They open up and down, and one or two sashes are movable. Being popular, they are available in the greatest variety of standard sizes.
- Width: 24 to 48 inches
- Length (height): 36 to 72 inches.
- Most popular size: 36″ × 60″
The windows are ideal for bedrooms, living rooms, hallways, and virtually any room that requires a balance of light and ventilation.
Sliding Windows
Sliding windows (or “gliders”) move horizontally along a track. Typically, they tend to be wider than they are tall, making them great additions to a space above kitchen sinks, in a basement or in contemporary homes where horizontal lines are desired.
- Width: 36 to 84 inches
- Height: 24 to 60 inches
- Common sizes: 36 × 24, 48 × 36, 60 × 48, 72 × 60 inches
Casement Windows
Casement windows are like a door that is opened on a side-hung hinge. They have good ventilation and visibility as there is no centre rail.
- Width: 16 to 48 inches
- Height: 24 to 84 inches
- Common size: 28 × 42 inches (often coded 2436)
They are tall and thin, which is why they are often used in the kitchen, bathrooms and rooms requiring additional air circulation.
Awning Windows
Awning windows open out from the bottom and hinge up at the top. The open sash is like a small roof, so they will let in ventilation even in light rain.
- Width: 16 to 48 inches
- Height: 24 to 84 inches
These are generally installed high on walls, above doors or in bathrooms where privacy and ventilation are both significant factors.
Picture Windows
Picture windows are non-functional windows that stay closed. They are noiseless and can be built a lot bigger than other types of displays, and are great for displaying scenic views.
- Width: 24 to 96 inches
- Height: 12 to 96 inches
A picture window in a living room or a stairwell can be a powerful design element and bring much natural light.
Bay and Bow Windows
Bay and bow windows extend beyond the wall to give a small alcove within the room. They are a combination of one fixed centre window and two or more operable side windows.
- Bay window width: 3 feet 6 inches to 10 feet 6 inches
- Bay window height: 3 feet to 6 feet 6 inches
They are larger investments than flat windows, adding interior space, character and panoramic views.
Standard Window Lengths by Room
The size of the window will also vary according to the room. The requirements for lighting, privacy, ventilation and security vary from space to space.
Living Room
The living room is typically the centrepiece of the house and can benefit from larger windows to allow plenty of light to enter and to showcase the outdoors.
- Typical width: 36 to 72 inches
- Typical height: 48 to 72 inches
A window or a large picture window that is 60 × 72 inches can provide a focal point and enlarge the room.
Bedroom
Bedrooms require both natural light and privacy, with safe egress in case of emergency.
- Typical size: 36 × 48 inches (around 3 feet wide by 4 feet tall)
- Common range: 24 to 48 inches wide and 36 to 60 inches tall
Many building codes specify that there must be at least one window in every bedroom that is able to be used for escape.
Kitchen
Most kitchen windows are above the kitchen sink or counter, which means they must be above the counter height, but allow light to enter.
- Typical width: 24 to 48 inches (2 to 4 feet)
- Average height: 36-60 inches
Sliding or casement styles are good choices here as they are easy to operate over a counter.
Bathroom
For bathroom windows, it’s important to strike a balance between light and privacy. It’s usual to choose frosted or obscured glass.
- Typical width: 24 to 36 inches
- Typical height: 24 to 48 inches
These are typically higher up the wall, typically beginning at about 48″ off the floor.
Basement
Basement windows are smaller, since they are near the ground level. However, if the basement is a living area or contains bedrooms, they will have to adhere to egress regulations.
- Typical size: 20 × 24 inches at minimum
A window well on the exterior of the basement window should also provide sufficient clearance for emergency exit.
Egress Window Requirements
Egress is a simple term that means a way out. Most building codes specify that bedrooms and completed basements must have a window that is big enough to get a person out in case of fire or other emergency, and big enough for a rescuer to get in.
Common egress requirements include:
- A minimum clear opening height of 24 inches
- A minimum clear opening width of 20 inches
- A minimum net clear opening area of 5.7 square feet (5.0 square feet for ground-floor windows in many codes)
These dimensions refer to the clear opening, not the entire frame, and are important to note when a window is open. However, a single-hung window that is 44 inches high can only open 22 inches, so you may need to install a larger window to comply with the rule. Because the entire sash swings out on casement windows, nearly all of the frame is considered a clear opening, and this makes them popular for egress windows.
Be sure to research your city or country building code, as it may vary.
Standard Windows vs Custom Windows
The difference between standard windows and custom windows is primarily one of price, time and design.
Standard windows are mass-produced and are less costly and easier to install. They work for most houses constructed in the past 50 years. They are also quicker to deliver as they are able to match common manufacturing runs.
Custom windows are designed for unique shapes, older homes with non-standard openings or modern designs that feature floor-to-ceiling glass. They are more expensive, longer to manufacture and require very precise measurements, but they allow for a perfect fit and complete design freedom.
The price difference between a standard and custom window size varies by brand and material, but is typically approximately 175 US dollars or more each. In the majority of cases, it is wiser to remain with the regular sizes, as this is much more economical.
Correctly Measuring Your Windows
The most crucial part prior to ordering is getting the measurement correct. A little error can result in gaps, drafts or a window that just won’t fit. Measure your windows accurately with these steps.
- Gather your tools. A good retractable tape measure will be required, along with a level, a notebook and a pencil. A small angle finder also comes in handy for older homes.
- Measure the width at three points. Begin at the top, middle, and bottom. Measure the inside of one side jamb to the other side jamb. Write down the smallest of the three measurements as your width measurement.
- Measure the height at three points. Take measurements from the top of the sill to the bottom of the left, middle and right head jambs. Once again, your final height will be the smallest measurement.
- Note the depth. Take the dimensions of the window frame opening to ensure that the new one fits inside and outside the walls.
- Check for a square. Level the opening to ensure that it is straight. Older houses tend to settle over time and may require minor adjustments.
- Compare with a standard size chart. If your measurements fall within an inch or two of a common dimension, then your window is most likely a standard size.
Common Mistakes to Avoid
Several little things can save a lot of trouble and money.
Only measure one width and one height. Window openings are not always square, and only a very small reading will provide a safe fit. It is important to note that the rough opening is not the same as the window size, as most window sizes quoted are the window size and not the rough opening. Never overlook local building codes, particularly those for bedrooms or basements. Lastly, never order without checking with the manufacturer since the difference between two brands with the same code is up to 1/4 inch or more.
Conclusion
When it comes to selecting the most appropriate standard length for windows, it’s not just a matter of numbers on a chart. The size you choose will influence the amount of natural light in your room, ventilation, your energy bill and the appearance of your home. Standard sizes offer the maximum of price, availability, and performance for the majority of projects, and custom sizes are available for unique designs and older structures.
Double-check the dimensions, local building codes, and whether the size listed is for the rough opening or window unit size before ordering. With the proper dimensions and some preparation, you can select a window that fits like a glove, will last for years and will actually increase the value of your home.
Frequently Asked Questions
What is the most common standard window length?
Answer
The most widely used window sizes for most homes are the 24×36″ (2030 window) size for smaller rooms or spaces, and the 36×60″ size for double-hung windows in living rooms and bedrooms.
Are standard window sizes the same in every country?
Answer
No Standard sizes are country dependent on the local building practices. Sizes may vary between the Middle East, Europe and the United States. Please consult the local manufacturer’s chart before ordering.
Can I replace a standard window with a custom one?
Answer
Yes, you can. If your current opening fits one of the standard sizes, however, a standard replacement will be cheaper and will go up quicker.
Do replacement windows come in the same sizes as new construction windows?
Answer
Yes. The window’s length and width are unchanged. The difference is a nail fin on the window’s frame, which is a feature of new construction windows for attaching to wall studs that is generally not found on replacement windows.
How much room does a standard window need around it?
Answer
A typical window requires about a ½” gap on either side and at the top and bottom of the rough opening. During installation, shims and insulation are placed in the space in between.
