Sliding windows, also known as sash windows, are a classic feature of various British homes. People appreciate them for their enduring beauty and practicality. These traditional windows have two frames, called “sashes,” that slide up and down within a frame. You can find these popular vertically sliding windows in Georgian and Victorian homes.
Their sophisticated design and ability to provide good ventilation mean they will continue to be in demand nowadays. Whether you are refurbishing a historic home or upgrading a modern one, it’s essential to know the correct sash window sizes. This knowledge helps create a visually appealing appearance and optimal energy conservation. In this guide, we will discuss how to measure your sash window sizes and why getting expert help is essential for accurate measurements.
Sash windows, frequently found in heritage homes, are prized for their historical authenticity. In contrast to casement windows that swing out, these windows slide up and down within the frame, adding elegance and enhancing ventilation without requiring additional space.
Throughout history, the size of sash windows has evolved to fit the architectural trends of each era. For example, windows tended to be taller and slimmer, reflecting the tastes of that time. Beyond their aesthetic appeal, these dimensions are also crucial for maintaining the historical charm of buildings. So, their architectural integrity can be preserved for future generations.
Choosing the correct sash window size involves more than just measuring from a chart; it also requires careful consideration of the window’s dimensions. It requires recognising architectural styles and how they influence window sizes. Standard sash windows are a more affordable choice because they’re mass-produced. Conversely, custom options tend to be pricier, but they provide a perfect fit that enhances both the appearance and value of your home.
When measuring sash windows—whether you are replacing, restoring, or installing new ones—you will need to record several key dimensions. Here is a breakdown to help you:
Frame Width: Take the inside width measurements of the frame at the top, middle, and bottom, using the smallest one for the new window.
Frame Height: Measure the inside height from the sill to the top of the frame at three points: left, centre, and right. Use the smallest measurement for each.
Frame Depth: Measure the existing frame (reveal) depth for the new window installation. Doing it this way ensures the new frame fits snugly within the opening and doesn’t stick out.
Diagonal Measurements: Measure diagonally (from top left to bottom right and from bottom left to top right) to check if the frame is square. If the measurements differ, the frame may not be square and may require adjustments.
Considerations for Older or Non-Standard Windows: Properties built years ago might have non-standard window sizes. You need to measure accurately and consider seeking an expert’s assistance, particularly if replacing multiple windows.
Find the perfect fit, whether you are renovating a historic home or creating a contemporary space:
Many manufacturers offer standard sizes, providing an affordable and efficient choice. These standard sizes are suitable for new builds or renovations with standard openings, where cost savings are a priority.
Widths: Standard widths commonly used include 36 in (914 mm), 48 in (1219 mm), 60 in (1829mm), 72 in (1829 mm), and 84 in (2134 mm).
Heights: Based on the window type, standard heights can vary but typically range from 609mm to 1524mm or more.
Historical Context: Although not definitive, Victorian and Edwardian sash windows typically had a standard width of around 1.2 meters (1200 mm).
Ideal for older homes with unique windows or design needs, custom sizes ensure a perfect fit, prevent drafts, and maintain aesthetics, especially when maximising natural light and views.
For Unique Openings: Custom-made sash windows are perfect for unique or oddly shaped openings, guaranteeing a precise fit.
Period Properties: Bespoke windows are essential for preserving the character and authenticity of period homes, which often feature unique measurements.
Recognising the various styles of sash windows can also assist in choosing the correct size:
Georgian sash windows showcase a grid-like pattern with 6 or more panes per sash, often tall and narrow, to maintain symmetry. Sizes typically range from 900 to 1,200mm wide and 1,200 to 2,100mm high.
Victorian sash windows typically feature a two-over-two pane arrangement, allowing for the use of larger glass panes due to advancements in glass-making technology. Their dimensions are generally measured between 1,000mm and 1,500mm in width and 1,200mm to 2,000mm in height.
Edwardian sash windows mix elements of Georgian and Victorian styles. They feature intricate designs and loftier sashes with either a single-pane or a six-over-two pane layout. Their sizes are typically similar to those of Victorian windows, but can vary based on architectural requirements.
With sash windows, you can make customisations to improve their look and functionality. Here are some options:
To match your home’s style, you can select from a variety of wood types and finishes. Options range from traditional whites to bolder shades, such as blues, greys, and even black.
Select from clear, frosted, or decorative glass to achieve the level of privacy and style you desire.
Enhance the appearance of your windows with stylish and durable handles, locks, and other hardware in finishes like brass, nickel, or chrome.
Add decorative sash horns for a timeless, elegant touch, especially if you are going for a classic style.
Incorporate glazing bars to add a grid pattern to your windows, giving them a classic look.
Find the perfect fit with a range of handles, locks, and other hardware that complements your window style.
Consider installing trickle vents to improve ventilation without sacrificing security.
Professional sash window measurements are essential for a successful installation that guarantees:
Fit and Functionality: Accurate measurements guarantee a precise fit, eliminating gaps that let in drafts and heat loss. This ensures the proper operation of the sash windows, allowing them to slide smoothly and securely.
Energy Efficiency: Windows that fit correctly are crucial to maintaining a home’s thermal efficiency. Even small gaps or incorrect sizing can result in substantial heat loss, leading to higher energy bills and compromised comfort.
Security: A precise seal formed through accurate measurements helps prevent unwanted entry points and enhances the overall security of your home.
Cost Savings: Although DIY measurement may seem tempting, professional measurement reduces the risk of expensive mistakes during installation, such as the requirement for modifications or repairs.
Historical Preservation: For properties within conservation areas, precise measurements are vital to meet regulations and preserve the historic character of the building.
Expertise and Accuracy: Professionals possess the knowledge and specialised tools to identify potential problems. They also account for any irregularities in the window opening, ensuring a precise fit.
Whether you are considering a sash window installation or replacement, understanding the precise measurements helps provide an accurate initial quote for planning. Original Sash Repairs has a team of specialists who will visit your property as scheduled and take exact measurements to design your sash windows.
Connect with us via 079 2223 8883 or polasm1325@gmail.com to arrange a free consultation and begin enhancing your home’s style and performance.
Copyright © 2025 Original Sash Repairs. All rights reserved.
