Sash Window Replacements
Handcrafted in Britain since 2012
Beautiful, handcrafted sash window replacements for London homes
Sash windows started appearing after the Great Fire of London and the changing requirements for buildings to prevent the spread of fire in future, but they really took off in the Georgian and Victorian periods. As you wander around London you will see different styles of glazing bar layouts, horn profiles, sizes, shapes, curves and these often can indicate the period in which the properties were constructed. They read like a chronology of tastes, styles and technologies, and as new technologies are introduced, they can be incorporated into new sash windows.
The stunning architecture of period properties is what attracts us to them, so at Wandsworth Sash Windows we know the importance of maintaining the charm and appeal of traditional styles, whilst also complementing this with modern double glazing, improved acoustic performance and draught proofing.
Sash Window Operating Mechanisms
The most common types of operating mechanism you will see on sash windows in London is weights and cords, or sometimes called box sash windows. This is the traditional, original style in which the sashes are hung on a cord which is attached to a weight (often now lead or steel), which is concealed inside the hollow box frame. These windows are most often set back from the face of the brickwork and fitted behind a checked reveal, which was a requirement following the Great Fire of London. Traditionally, the cords would have been made from waxed cotton, but now they are most commonly a plaited nylon which massively decreases the risk of fraying and breaking.
An alternative operating mechanism is a spiral balance, which is spring that is tensioned to match the weight of each sash, so only a small amount of force needs to be applied to open the window. These windows have narrower, solid frames and are most commonly found in newer dormers or extensions, where the windows are fitted closer to the face of the brickwork or building, and there is no checked reveal.
Services you can choose from
We offer two services for sash windows, each suited to different situations and budgets:
- Sash replacement
- Complete replacement
Each has their benefits and different situations or applications where they may be preferable.
The sash replacement service involves fitting new, double-glazed sashes into your existing box or spiral frames. Often we find that your existing frames are in a suitable condition to remain in place. The new sashes are fitted and hung on new cords or spiral balances, fitted with new draught excluders and modern locking mechanisms.
This service can be beneficial where cost is a main consideration, as it is cheaper than the alternative, but also where removing the existing frame would cause unnecessary disruption. For example, if a window is in the bathroom and you have tiled over the box frame, fitting new sashes into the existing frames would prevent the need to remove the box frame and potentially retile the bathroom.
The complete replacement service is the more comprehensive of the two and involves completely removing the frame and the sashes, and replacing with new. This is beneficial because it means that your new sash windows are perfectly square and will slide up and down effortlessly.
The benefits of replacing your sash windows
In a poorly insulated room with ill-fitting windows, the air is completely changed around three times every hour. This means you are paying to heat air that is then simply lost, driving up the price of your energy bills. Double glazed and well insulated sash windows save money.
A huge portion of the surface area of your external walls will be glass, and single glazing performs very poorly in keeping heat in. Replacing your windows with new, double-glazed versions will ensure that you can retain much more of the heat in your property in winter.
As summers get warmer, it can be difficult to keep your home cool. New sash windows can help with this in two ways. Firstly, the design of sash windows allows you to open the top sash part way, and the bottom sash part way, creating circular air flow to allow cool air in through the bottom, and hot air out through the top. If your sash windows are stiff or do not open at the moment, then you aren’t able to get this benefit. The second benefit is that double-glazing has a better solar g-factor – a measure of how much heat from sunlight passes through the glass – than single glazing, this means that the amount of heat transferred from the sun into your property in the summer is reduced, meaning cooler temperatures.
How much do replacement sash windows cost?
Design complexity is the biggest driver of sash window replacement cost — often more so than size. The more complex a sash window looks (with a complex glazing bar pattern, or a curved top for example), the longer it takes us to manufacture it for you, and this is the main driving factor.
The cost of the materials for a sash window actually makes up a very small percentage of the cost (around 5-10%), two windows of very different sizes can take almost identical time to make if their designs are equally complex. So, if you were to double the size of a sash window, it may only increase the cost by around 10%.
As a rough guide, for the sash replacement service you can expect prices starting around £1,000 per window and going up to £1,500 for more complicated windows.
For the complete replacement service, the cost generally starts around £1,700 per window and can go up to £2,500.
Bear in mind that this is for a double-glazed window, with a standard specification. If you decide to opt for vacuum insulated glass, a custom paint finish, or bespoke ironmongery, this can increase the total.
What do you get for that price?
All of the prices that we quote include installation, regardless of which option you decide upon. We survey and measure the windows, they are manufactured and fully painted to top coat by us in our workshops. All work is covered by our 10-year insurance-backed guarantee and, for complete replacement services you will receive a FENSA certificate to confirm that the products have been manufactured and installed in compliance with current Building Regulations, which you will need when you come to sell your home.
Frequently Asked Questions
One of the most important considerations in these designs is the longevity of the products. We understand that replacing your windows is a costly endeavour and our customers would not want to be replacing the same window every 10 years. We also take traditional designs & styles into account when manufacturing windows & doors, trying
to ensure replacement windows are as sympathetic to traditional styles as possible. Some parts of your new windows may not be the same as your original. This is because we need to combine all of these considerations to ensure we provide the highest quality window, which is exactly what we do.
All the sash windows and other windows and doors that we supply are fully compliant with Document L Building Regulations. New sash windows, casement windows or doors that fit into existing frames are not required to comply with regulations as such work does not affect the structure of a building. Listed buildings and conservation area properties may be exempt from regulations – your local planning authority will be able to advise you if you are unsure.
That depends on your budget. It can be cheaper to repair your windows, but replacement is the better, long-term solution. We can undertake a site survey to determine which option is best for you.
We are members of and certified by FENSA, which allows us to self-certify our installations as compliant with building regulations.
As standard, our sash windows are fitted with a Hardwick hook lock and roller stops.