Sliding Sash Windows

Types of Sash Window

Sash windows are made of two panels that slide past each other to open. These panels (also known as sashes) may slide up and down or side to side. A sash window doesn’t have a hinge opening. This traditional type of window is a popular choice, especially for period properties. But did you know how many options are available when it comes to different types of sash window?

You can choose from different styles, mechanisms, frames and glazing types which makes sash windows a great choice for lots of property types. Find out if there’s a type of sash window that’s right for you!

Sash Window Style

If you’re trying to maintain the character of a period property or even a listed building in a conservation area, it’s important to choose the right type of sash window. There are subtle differences based on period so here’s what to look out for.

Sash windows have astragal bars which divide the sashes into smaller areas. It’s the pattern of these that demarks the period.

Example of Sash victorian bar

Georgian: in the Georgian era sash windows featured a six over six pattern. This is because manufacturing processes in this era only allowed small glazed panes to be produced, so a good number of these were needed to create a window. The sense of symmetry this creates is a very Georgian look.

Victorian: the pattern in Victorian times was a two over two design. Windows from this era also tend to be more lavish, with sash horns added to help strengthen the joints which had to support the larger glass panels.

Edwardian: a six over two pattern was developed in the Edwardian era, combining the best of the Georgian and Victorian approach. Sash horns were still used to support the larger glass panes which let in plenty of light.

Sash Window Mechanism

Whether you’re aiming for a period look or just enjoy the charm of a sash window, you’ll need to decide which type of mechanism to opt for. There’s a traditional and a more modern option available.

Sliding Sash windows mechanism detail

Cord and weight sash windows, also known as box sash windows use the traditional style of mechanism. These types of sash window use a system of weights and pulleys on the sash cord to open and close the window. The weights are there to counterbalance the sash, making the movement of the heavy window run more smoothly. This mechanism is hidden from view inside a box, which is why they are also commonly known as box sash windows. (Visit our Box Sash Windows FAQ page to learn more.)

Spiral balanced sash windows use a more modern mechanism. They also use a counterbalance created by a set of springs inside a PVC tube. These are often visible which can be something to consider when making your choice. However, they are also easier to install as they can be installed into normal brick openings. They are a great option for new builds because they offer the charm of a traditional sash window coupled with modern technology and increased security.

Window Frame Types

Timber Sash Window Frame

Different frame types can also offer varying benefits and appearances. Choosing the right frame material will allow you to get a sash window that looks and performs in just the right way for your home.

Wood: wooden window frames are classic, natural and attractive. They are a great choice for a traditional style like a sash window, especially in a period property. However, wooden windows need regular maintenance and care to keep them in good condition and prolong their lifespan.

Upvc: this cost effective and durable material is a favourite for windows. It doesn’t require a lot of maintenance and is a great all-rounder. However, it doesn’t offer a very traditional appearance so it can look quite jarring in a period property.

Aluminium: modern sash windows can be made of aluminium for durability and strength. As aluminium is so strong it can support large panels of glass, resulting in slimmer frames and more glass. It’s also unlikely to bend and twist as weather conditions change like wooden frames can. But just like uPVC, as aluminium frames use very modern materials, they can look out of place in a traditional home.

Glass Types

If you haven’t already found the ideal sash window, you might need to consider the choice of glass. There are two types to choose from.

Clear glass is the most common choice, giving you a view through your windows and letting maximum natural light into your home. Most people choose this unless they’re installing the window in a room they need to maintain some privacy, such as a bathroom.

Frosted glass can be used to let natural light filter through whilst obscuring the view. The most common application is for bathrooms, but it’s also quite common for use in commercial spaces too.

Hopefully, our guide has helped you to understand how varied sash windows can be. Whatever type of property you have, there’s a sash window choice to fit. Although they’re perfect for bringing historical charm to your home, sash windows can add an interesting touch to a new build too. Make sure you’ve considered all the types of sash window before you settle on the ideal choice!

To read more about box sash windows, read our helpful box sash windows FAQ.

Browse our available selection of Box Sash Windows.

Conservation casement windows on a snowy cottage

What Are Conservation Windows?

Flush casement windows

Conservation windows are fitted to period properties, or properties within conservation areas that are required to adhere to strict requirements. These requirements are listed in a conservation order created and upheld by the local authority.

A conservation window should be sympathetic to the style period of the property. Timber flush casement windows and flush sash windows are a great way of retaining the character and charm of a period property. The interpretation of conservation can be ambiguous. You will need to rely on the advice of your local conservation officer.

For conservation windows, extra options should be available. For example, the addition of glazing bars to mimic cast iron bars on Victorian windows.

With timber frames, there is a choice of softwood or hardwood. A heritage colour palette may feature colour choices approved by local authorities to fit with the setting. New windows that replace or imitate period windows should meet today’s standards and regulations. These windows should not compromise on thermal efficiency or security.

You should check that any new timber frames are backed by a rot and fungal guarantee for peace of mind.

Always consult your local conservation officer before purchasing windows. Ensure you are in line with the specific needs of your project.

Of course, conservation windows aren’t just for period properties within conservation areas. What better way to inject some character into a modern build than with beautifully crafted timber windows?

What is a Conservation Area?

Casement windows in conservation area

A conservation area is a designated area of important historical interest and therefore worthy of preservation.

Conservation areas of towns or villages are protected in terms of town planning, trees, landscaping and construction. In a conservation area, the local authority will hold a conservation order. A conservation order is a list of regulations. New developments cannot be approved or signed off until these regulations have been met. New installations or replacements must blend seamlessly into their surroundings. A large part of this depends on the use of materials and construction methods.

If your installation does not satisfy your conservation officer’s stipulations, they can order it to be removed.

If your installation does not satisfy your conservation officer’s stipulations, they can order it to be removed. It is very important to consult with your local conservation officer prior to carrying out any work. They can help you understand the criteria you need to meet.

How do I know if I live in a conservation area?

To find out if you live in a conservation area, contact your local planning authority (LPA). Your LPA can tell you why the area was designated as a conservation area. They will also map where the area extends to and explain the level of legal protection in place.

If you have any questions about conservation windows, please contact our friendly, fully trained staff who are on hand to help.

See also:

Fully Compliant Conservation Windows

Conservation Casement Elegant Windows 

Guarantees on Conservation Windows

water condensation

Why Does My Double Glazing Get Condensation On the Inside?

This can be a worrying find, but the good news is that condensation inside windows actually indicates that your windows are working as they should. In fact, you’re as likely to get condensation on new windows as old windows, and new windows may even increase condensation, since they should reduce draughts in the home.

That said, condensation on windows is something we should try to reduce, since it can damage window frames. Plus, who wants wet window ledges? It’s also indicative of a bigger problem – excessive moisture in the home.

Condensation between double glazing panes is a different problem and indicates a broken seal that will need fixing or replacing – but we will discuss this further on. For now, let’s look at why you get condensation on the inside of a window in the first place.

Why do you get condensation on the inside of a window?

One of the main advantages of double glazing is its ability to prevent heat from moving from one side of the glass to the other. It does this by sandwiching a vacuum (or a layer of inert gas) between two sheets of glass. When heat energy builds on one side, it has trouble passing through this inner layer, and so instead is conducted back into the room.

This prevents heat escaping, and will reduce your energy bills, but in doing so it will create a considerable difference in heat from one side of the glass to the other. It’s this difference that creates the conditions for condensation.

Cold air contains less energy than warm air, and it’s less capable of keeping water vapour in its gaseous form. This means that the air inside your home will be damper than the air outside. When this air hits a cold surface, like a window, it will lose the energy necessary to hold onto the airborne water, and so that water will be deposited. Over time, this effect causes the build-up of water condensing on the glass, thus causing condensation on the inside of your windows.

In short, window condensation is warm moist air that turns back into water as soon as it hits a colder surface that it cannot pass through.

Where does condensation happen in the home?

You may notice more condensation happening in certain rooms of the house:

  • The kitchen
  • The bathroom
  • The bedroom
  • The utility room

Cooking, showering, bathing and laundry all create substantial moisture which, unless you keep the rooms very well ventilated, will settle on the windows. This probably isn’t surprising. What is puzzling is why we get condensation on bedroom windows, since we’re probably not cooking or showering in there.

Why is there condensation on my bedroom windows?

During the day we move around the house but at night we’re confined to one small space for 8 hours or more, often with the door closed. The water vapour we lose through breathing over those 8 hours builds up as moisture in the air. As we tend to keep bedrooms a little cooler than the rest of the house and turn off heating overnight, the surface of the windows will be colder. The moisture in the air will condense into water as it hits the cool surface of the windows, creating condensation on the inside of your bedroom window.

With the temperature difference between outside and inside larger in winter, you often find more condensation on your windows during colder months.

Why is condensation bad?

Condensation can reduce the lifespan of a window, as it’ll encourage the growth of mould which can damage the frame. It can also be taken as evidence that the humidity inside your home is excessive – which can be a health concern.

How do you stop condensation on windows?

To prevent condensation settling on windows we need to take steps to reduce the amount of condensation in the home generally. Ideally, we want humidity levels to be at around 50%. In order to achieve this, you want to improve ventilation in your home – some steps you can take include the following:

How To Reduce Condensation In The Home

Laundry drying outside
Dry Laundry Outside When Possible

There are many steps you can take to stop condensation on your double glazed windows. Here are some ways to reduce condensation in the home:

  1. Ventilate Rooms

    Aim to open windows for about 20 minutes daily (yes, even in winter!) This will allow the damp air to escape and (unless it’s especially humid outside) dry air to replace it. Installing trickle vents can help reduce condensation too.

  2. Use an Extractor Fan

    If you’re cooking or showering, using an extractor fan will help to remove damp air from your room before it can settle on surfaces and cause problems.

  3. Use a Dehumidifier

    If the steps above don’t remedy the problem, or at least don’t sufficiently reduce condensation in the home, you may want to invest in a dehumidifier, which will extract moisture from the air.

  4. Don’t Dry Laundry Inside

    Drying wet clothes inside significantly increases the amount of water vapour in the air. The water has to go somewhere, after all. If drying laundry outside isn’t an option, ensure the space around your laundry is as ventilated as possible.

  5. Rearrange Your Houseplants

    Did you know that the more houseplants you have, the more moisture you’ll find in the air? Try moving your houseplants outside during the winter or choosing plants that absorb humidity, such as ferns, palms or cactus.

Manage other humidity sources

When you’re taking steps to guard against excess humidity, you’ll want to consider the things that can contribute to it. One of the most obvious causes are the living beings which inhabit a house – each of which, be they humans, dogs, cats or guinea pigs, will emit water vapour over the course of the day. Paradoxically, you might also encounter an uptick in humidity when you return from a spell away – as an empty house will be unheated, and therefore prone to absorbing moisture, which will be released when the heat rises again.

Do double glazed windows stop condensation?

Whilst condensation can be worse on single glazed windows (due to the internal surface of the window being much colder than the internal surface of a double glazed window), replacing single glazed windows with double glazing is not enough to eliminate the problem. The reason being is that although the inside of your new windows will be warmer, they will simultaneously eliminate draughts. This will reduce ventilation, and contribute to the build-up of moisture. What’s more, double glazing cannot remove the sources of water vapour inside the home, such as cooking or showering.

Acute causes of condensation on windows

If your condensation has appeared almost overnight, then you might be wondering what could possibly have caused it. There are several potential short-term contributing factors.

How Does Winter Cause Condensation?

When the weather outside gets cold, the chances of condensation occurring increase substantially. This is because the difference in temperature between inside and outside is greater, cooling your windows more and encouraging water vapour to condense on the glass. At the start of winter, it is therefore worth taking preventative steps to reduce preventable causes of double glazing condensation before they have a chance to develop.

Why Do New Windows Cause Condensation?

Newer double-glazed windows are able to do their job much more effectively than old ones, keeping an airtight seal between the indoors and out. Without ventilating airflow, don’t be surprised to see more condensation after getting your new windows installed.

Can Underfloor Heating Cause Condensation?

Radiators help warm air to rise and circulate, so if you’ve swapped out your radiators for underfloor heating, you might see an uptick in condensation on your windows.

What about condensation between double glazing panes?

So far, we’ve been talking about condensation on the inside of the glass – but what happens when vapour gets in between the window panes? This means that the window seal has sprung a leak, which has allowed water vapour to get in. The inert gases inside a modern double-glazed window contribute enormously to its ability to retain heat, so if yours is showing this symptom, it’s probably time to replace your windows.

For more information, take a look at our blog post on why condensation forms between window panes.

Looking for new windows for your home? Browse our JELD-WEN range, including sliding sash and casement windows. We also supply a variety of timber windows, aluminium windows and more. Just get in touch with our helpful team if you have any questions.

Image credit 1