What is The Difference Between The Traditional Box Sash Sliding Window and The Spring Sash Window?

Posted: 23 May 2024

Timber sash windows are among the most popular in homes across the UK, and you will see them in every sort of residence, from contemporary townhouses to country cottages. But not all sash windows are the same.

Different Types of Sash Windows

There are two types of sash windows. The first is known as a box sash sliding window. This is the more traditional type of sash window commonly found in Victorian and Georgian homes. It comprises two vertical sashes that slide up and down in a box frame. Box sash sliding sashes use a weights and pulleys system, whereby a heavy weight is connected to the window sash through a sash cord and a pulley, counterbalancing the sash and aiding movement.

Spring sash windows utilize a spring-loaded mechanism instead of weights and pulleys. The springs are usually housed within a metal tube and are attached to the sashes to assist with movement. They are popular in more contemporary buildings, although they can also be designed to replace box sashes in older properties.

Pros and Cons of Sliding or Box Sash Windows

If historical authenticity is important to you for a period property, then box sash sliding sash windows with cords and weights are the obvious choice. The mechanism is time-honoured and proven to work for as long as it does. Also, the historical issues with the cords have been overcome by using a pre-stretched nylon cord.

Pros and Cons of Spring Sash Windows

Spring sash windows are lighter and take up less space, so they are easier to install in restricted spaces. They are typically used in new-build properties and set within flush reveals, as opposed to the box sash, which sits in a recessed reveal. The spring sash window operation is not quite as smooth as the Rolls Royce box cords and weights, but it is a more economical option.

Box the box sash and spring sash can provide the same sight lines externally and internally; it is just a case of positioning them in the correct reveal and showing the same liner margin externally. The only way to tell the difference is to see a tube that houses the spring as opposed to the

traditional cord.

Triple glazed spring sash windows

Which is For You?

Both types of sash windows provide an elegant period solution that is secure, energy-efficient, and will last for many years with care and regular maintenance. Choosing which one really boils down to factors such as architectural integrity (particularly in historic homes), personal preference in terms of aesthetics, and cost. The spring-balanced sash is the most economical.

Common FAQs

Can I Change Sash Windows in a Conservation Area?

The rules vary between authorities, so check with your local council. Usually, they will need you to submit a planning application and ensure that the new windows are in keeping with the age of the home and the neighbourhood.

What is The Most Common Form of Sash Windows Ordered by Lomax + Wood’s Clients?

Spring balanced sash windows are the more commonly specified. As mentioned earlier in the correct architectural detail, they can appear the same externally as the box sash window.

Are Sash Windows Energy Efficient?

Very much so. Lomax + Wood’s Kensington and Chelsea timber sliding sash windows are independently tested to provide superb acoustic, thermal, and security performance, meeting and exceeding the standards required by the Building Regulations.