06 May 2025
Not sure whether to replace your whole sash window box or just the sashes? This guide from SashWise explains the pros and cons of each option to help you make the right choice for your home.
Sash windows are a timeless and elegant choice for homes. They not only enhance a building’s look and appeal but also provide essential natural light and ventilation whilst maintaining security.
When considering new sash windows for your home, there are two main options: complete sash window replacement (including the sash window surround – called the sash box) or replacement sashes (replacing the sashes in the existing surrounding sash window boxes). Here we explore the key differences between these two options and weigh the pros and cons of each to help you make an informed choice for your home
Sash window boxes are standalone window units that are installed into an opening in your home’s wall. They consist of a frame, sashes, and glazing, forming a complete window system.
Customisation: Sash window boxes can be customised to your exact specifications. You can choose the frame material, glazing options, and design elements to match your home’s style.
Efficiency: Modern sash window boxes often come with energy-efficient features, including double glazing and weatherstripping, which can improve your home’s insulation and reduce energy costs.
Versatility: Sash window boxes can be installed in various architectural styles, from traditional to contemporary, and are suitable for both residential and commercial properties.
Easy Maintenance: Sash window boxes are designed for easy cleaning and maintenance. You can access both sides of the glass, making it simple to keep them in good condition.
Enhanced Security: With advanced locking systems , sash window boxes can provide enhanced security for your home.
Cost: Customised sash window boxes can be expensive compared to other window options, especially if you require intricate designs or high-quality materials.
Installation Time: The installation of sash window boxes is typically more time-consuming.
Permanent: Once installed, sash window boxes are not easily replaced or modified, so it’s important to make the right design choices from the beginning.
Historical Preservation: In historic properties, installing sash window boxes may not be allowed, as it can alter the original architecture and aesthetics of the building.
New sashes in existing boxes, also known as replacement sashes, are designed to fit into the pre-existing frames of older windows. This option allows you to retain the original window box and frame while upgrading old or loose sashes and draughty single or double glazing.
Cost-Effective: New sashes in existing boxes are often a more cost-effective solution compared to complete window replacements, making them a popular choice for those on a budget.
Preservation of Architectural Aesthetics: For historic homes or buildings in conservation areas, retaining the original window boxes is crucial for preserving the integrity and historical value.
Quick Installation: Replacement sashes can typically be installed more quickly than installing entirely new window boxes, reducing the disruption to your home.
Energy Efficiency: Upgrading the sashes and glazing in existing boxes can significantly improve energy efficiency and insulation, leading to potential cost savings and reducing the environmental impact.
Limited Customisation: While you can choose the style and design of the sashes and glazing, you may have fewer customisation options due to the existing frame dimensions.
Frame Condition and Performance: The condition of the existing window box frames can affect the performance of the sashes. If the frames are in poor condition, they may need repairs or reinforcement.
Design: While preserving the original boxes is a benefit for historical properties, it may limit design choices for homeowners looking for a different style.
Maintenance: Maintaining new sashes in existing boxes can be more challenging due to potentially limited access to the exterior glass for cleaning and maintenance.
The choice between new sash window boxes and replacement sashes in existing boxes will depend on your specific needs and circumstances. If you have a budget to accommodate custom features and want complete design flexibility, sash window boxes may be the better choice. However, if you have historical considerations, limited funds, or want to maintain the existing design of your property, replacement sashes in existing boxes can be a more cost- effective choice. In either case, both options provide the beauty and functionality that sash windows are known for.
It’s essential to carefully weigh the pros and cons and consider your unique requirements before making a decision that best suits your home and lifestyle. Whichever option you choose, sash windows will undoubtedly add a touch of classic elegance to your home.
