A Guide to Choosing the Right Window Size
8 minutes
December 16, 2021 To determine the style and size of windows you need for your area, you must first determine with the window contractor if you need custom window sizes or ordinary windows. Sourcing standard-sized replacements can be challenging, especially for older or uniquely designed homes, making custom windows a beneficial option despite their longer wait times and higher costs. The typical window size depends on the home’s age and the windows utilized. Renovations to older homes may have resulted in larger, more modern window openings.
While the conventional window proportions for each area will vary, they should be consistent with the sizes commonly utilized by contractors and builders. When designing a home, typical window proportions should be taken into account when determining which windows will allow the most natural light into the space.
Professional roofer ARCH Exteriors will provide you with some basic options to make the selection process much easier.
Understanding Standard Window Sizes
What Are Standard Sized Windows?
Standard sized windows are the most common dimensions used in newly built homes and are widely available from top-quality window brands. These standard sizes simplify the buying process, making it easier for homeowners to find the right windows for their homes. Standard window sizes are not limited to a few basic sizes, but rather have several standard sizes for each type of window. This variety ensures that homeowners can find windows that fit their specific needs without the hassle of custom orders. Whether you’re looking for double hung windows, picture windows, or casement windows, standard window sizes offer a convenient and cost-effective solution.
Benefits of Using Common Window Sizes
Using common window sizes can make the window buying process easier, saving time and money. Measuring for replacement windows is simpler when the size is common, and standard prices can be easily found online or by speaking with a representative. Common window sizes are typically more affordable than special shape windows, which require custom framing and glass, increasing costs. Additionally, standard window sizes are readily available, reducing the wait time for delivery and installation. This makes them an ideal choice for homeowners looking to upgrade their windows quickly and efficiently.
How to Read Window Sizes
Window manufacturers use a four-digit notation to indicate window sizes. The first two numbers refer to the window’s width, and the last two numbers indicate the height. For example, a window labeled as 2438 is 2 feet 4 inches wide and 3 feet 8 inches tall. The window size notation can refer to the rough opening or the exact window size, so it’s essential to verify whether the size is referring to the opening or the exact window size. Understanding this notation helps ensure you get the right fit for your window frame, whether you’re installing new windows or replacing old ones.
Window Types and Their Characteristics
Double Hung Windows
Double hung windows are the most common type of window in modern homes, featuring two sashes that slide up and down, with a latch system in the middle. They are suitable for various rooms, including living rooms, bedrooms, bathrooms, and kitchens. Standard double hung window sizes include 24×36 inches, 24×48 inches, 30×36 inches, 30×48 inches, and 36×48 inches. Double hung windows are a popular choice for homeowners who want to add ventilation and style to their homes. Their design allows for easy cleaning and maintenance, making them a practical and attractive option for any room. Whether you’re looking to replace old windows or install new ones, double hung windows offer a versatile and timeless solution.
Standard Window Sizes
To find out what size windows your home needs, take measurements of all the windows that require replacing or updating. Not all house windows are the same size. The size of the bathroom, basement, and kitchen windows vary. While picture or bay windows are conventional window proportions for their type, they are nevertheless larger than single-hung, double-hung, or casement windows. It is usually best to have a home siding replacement company measure your windows.
Standard window sizes vary depending on the type of window you’re planning to use for your home. Here are the most common sizes for standard windows:
Double-hung windows
- Width: between 24 and 48 inches
- Height: between 36 and 72 inches
Picture windows
- Width: between 2 feet and 8 feet 8 inches wide
- Height: between 1 foot and 8 feet
Sliding windows
- Width: between 36 and 84 inches
- Height: between 24 and 60 inches
- Standard sliding window sizes include 3 feet by 2 feet and 6 feet by 4 feet
Bay windows
- Width: between 3 feet, 6 inches and 10 feet, 6 inches
- Height: between 3 feet and 6 feet, 6 feet tall
Casement windows
- Width: between 1 foot, 2 inches and 2 feet, 11.5 inches, wide by 4 feet
- Height: between 2 feet, 5.5 inches and 6 feet, 5.5 inches
Awning windows
- Width: between 2 inches and 3 feet, 10 inches, wide by 3 feet
- Height: between 1 foot, 8 inches and 7 feet, 8 inches
How to Choose the Right Window Size
Choosing the right window size isn’t just about aesthetics — it’s about functionality, compliance, energy efficiency, and natural light. Here’s a step-by-step guide to help you make the best decision:
1. Start with the Room’s Purpose
Different rooms require different window functions:
- Bedrooms: Require egress windows for safety, typically at least 24″ high by 20″ wide, with a minimum opening of 5.7 sq. ft..
- Living Rooms: Prioritize natural light and airflow; consider larger picture or double-hung windows, often 36″x60″ or bigger.
- Bathrooms: Require privacy + ventilation. Small frosted casement or awning windows (like 24″x36″) work well.
Tip: The window area should be at least 10% of the room’s floor area to ensure enough daylight.
2. Know Your Local Building Codes
Window sizes often need to comply with:
- International Residential Code (IRC) for egress and safety
- State-specific energy codes (like U-factor and SHGC limits)
- Historic district rules (if applicable)
3. Understand Standard vs Custom Sizing
- Standard Sizes: Easier to install, more affordable (e.g., 24″x36″, 36″x60″).
- Custom Sizes: Ideal for older homes or unique designs, but more expensive and may require framing changes.
4. Balance Window Height and Placement
Think beyond just width:
- Windows placed too high may block your view.
- Windows placed too low may reduce privacy or wall space for furniture.
- For symmetry, align window tops across rooms (even if bottom sills vary).
Height Tip: A common sill height is 24–36 inches off the floor, with a head height of 80–96 inches.
5. Consider Furniture and Wall Layout
Before finalizing the window size:
- Plan where beds, couches, or desks will go.
- Avoid placing large windows where furniture will block them.
- Use narrower windows in tight wall spaces or near corners.
6. Use a Window Size Visualizer or Planner Tool
Interactive tools or augmented reality apps can help you:
- Visualize window sizes on your wall
- Compare side-by-side configurations (e.g., 2 small windows vs 1 large)
- Test light angles throughout the day
7. Consult a Pro
Don’t go it alone! Consult with:
- A licensed contractor (for structural openings)
- A window installation expert (to verify fit and function)
- An energy efficiency specialist (for rebates and insulation recommendations)
Making the Best Window Size Decision
Single hung windows are a popular choice for many homes. Unlike double hung windows, where both sashes can move, in single hung windows only the bottom sash operates. This can affect egress requirements and functionality. Standard sizes for single hung windows are similar to those of double hung windows, making them a versatile option for various home styles.
ARCH Exteriors, LLC is honored to be HAAG-accredited, a title reserved for roofing specialists due to the certification’s stringent requirements. We specialize in roof repair and replacement, siding installation, window and door replacement, and gutter installation. To schedule an appointment, please call (301) 215-2343. You may also request a free estimate by completing our contact form.
FAQ’s
What is window frame size?
The window frame size refers to the outer dimensions of the window, including the frame that holds the glass in place. It determines the rough opening needed for installation and varies based on window style, manufacturer, and intended use. Standard window frame sizes range from small casement windows to large picture windows, depending on the home’s design.
What is the golden rule for window size?
The golden rule for window size suggests that windows should be around 20% of a room’s floor area to provide balanced natural light and ventilation. This helps create a well-lit, comfortable space without excessive heat loss or glare. However, factors like room function, climate, and energy efficiency should also be considered.
How do I choose the right size window?
To choose the right window size, consider the room’s dimensions, ceiling height, and desired natural light. Ensure the window size meets building codes for ventilation and egress, especially for bedrooms. Also, factor in aesthetics, energy efficiency, and how the window will fit with the home’s overall architectural style.
