Sash Windows: The Complete Guide

Sash windows are cheaper and less maintenance than wooden sash windows

A double glazed sash window costs between £300 and £900

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In this Guide to Sash Windows:


What are Sash Windows?

sash windows

Double glazed or not, sash windows are the most common type of window in UK homes. Why? They’re a good balance of affordability and durability – plus, they don’t look bad.

Most often they’re white and consist of around two panes of glass per window, so that one (or both) of the panes can slide up and down to open and close the window.

If only one of your panes of glass slides up and down, you have a hung sash window; a double hung sash window means both panes of glass move up and down.

Did You Know?

A double-glazed sash window costs between £300 and £900 per pane of glass.

Why does everyone seem to want a sash window? Sash windows have remained popular in the UK since 1700s to early 1900s, especially in London.

With a lengthy history, sash windows tend to suit traditional homes, but uPVC sash windows can also work well on more modern houses styled like period properties.

This guide tells you all you need to know about double glazed sash windows today. Find out which type yours are, and how much new ones will cost you. Plus, you can discover which companies near you can help you get one fitted if you fill in this form.


Types of Sash Windows

Sash windows come in a wide range of types, with one to suit most budgets and preferences. The most popular variety is uPVC, but wooden and aluminium frames are also common in the UK.

Besides the frame material, there is the question of whether you are looking for double or triple glazing. As you’d expect, triple glazing costs that bit extra, but may be worth it if you’re needing to drown out a particularly busy road. We explain more below.


uPVC Sash Windows

People tend to opt for uPVC sash windows as a cheaper, slightly lower maintenance alternative to traditional wooden sash windows.

The cheapest type of sash windows uses uPVC material. uPVC double glazed sash windows tend to cost between £300 and £950 per window.

Window Size
50cm x 50cm
£300 to £600
50cm x 50cm
£600 to £700
100cm x 50cm
£400 to £700
100cm x 50cm
£700 to £800
100cm x 100cm
£500 to £725
100cm x 100cm
£725 to £825
120cm x 120cm
£550 to £825
120cm x 120cm
800 to £950

*Prices exclude installation costs.


Wooden Sash Windows

After uPVC, wood is a popular finish for sash windows. They tend to look elegant, and befitting of a period property, which usually house sash windows.

Why choose wooden sash windows? Paying that bit extra for wooden sash windows can pay off in the long term, as the wood (or wood effect) finish can add value to your home.

Remember that if you have existing wooden frames around your windows, and you’re keen to replace them with plastic ones, you may need planning permission, depending on where you live.


Double Glazed Sash Windows

Did you know double glazed sash windows are the number choice of new window in UK homes.

Are they worth it? Double glazed windows have two panes of glass, which means they can be effective in protecting you from noise or car pollution. But don’t expect 100% results – it’ll be more the case of reducing rather than removing your pain point.

How does double glazing work? Double glazed windows have two panes of glass, and a layer of gas (usually argon) in between. You can enjoy a warmer home – and lower heating bills. Plus, two panes of glass are harder to break than one, so you’ll feel safer.

upvc double glazed sash windows review
*Based on a survey we conducted in May 2018 of 42 UK homeowners who've had double glazed uPVC sash windows installed in the last 2 years.


Triple Glazed Sash Windows

Of course, you can also get triple glazed sash windows. As you would expect, triple glazing comprises an extra layer of glass, so you have three panes instead of two.

Why get triple glazing? Triple glazing takes all the benefits of double glazing and notches them all up. That means added protection from sound and pollution. That said, whether you think it’s worth the added costs will be up to you.

Read our guide on triple glazed windows to find out if they're what you’re looking for.


Sash Windows Prices

So, how much do sash windows cost? The cost of double glazing sash window starts from around £300, and companies charge up to £900 per pane of glass, depending on the size and finish you go for.

It’s normal to think long and hard about the price of your new double glazed sash windows. But the good news is most companies will offer you the option of buying them on finance. That means spreading the cost over several months and only paying interest, if there is any.

But be careful. Buying your uPVC sash windows on finance often involves paying hundreds (or even thousands) of pounds more than your windows are actually worth. Plus, you risk falling behind on payments, and having to deal with penalties.

If the pricing is a worry, you can find out if you qualify for financial support from the Government for your new sash windows. You can read our guide to double glazing grants here.


Installing and Repairing Sash Windows

The largest double glazing installers in the UK are Anglian, Everest, Safestyle and Zenith, and all offer sash windows.

Why are they so popular? The truth of the matter is many people flock to the bigger companies because they trust them more than local suppliers. You can rely on a named brand to receive quality windows, and reliable installations.

This is the range of new windows or double glazing repairs on offer with these suppliers:

Let’s have a look at their range of uPVC double glazed sash windows:

Energy Rating
A++ to A
10 years
10 years
10 years
10 years

So, should I look locally or nationwide? That’ll be your decision. You often have more support if anything goes wrong with a larger company. But a long-standing independent window installer with good ratings may also be trustworthy.

To help you decide, look for a firm that’s accredited by one of the Government’s Competent Persons Schemes (CPS), FENSA or CERTASS. That way, you can be sure your window fitters are fully qualified, reliable, and compliant with those all-important Government building regulations.

But the main advantage is the protection you get should anything go awry. If that’s the case, you can rest safe in the knowledge there’ll be a full complaints procedure with an ombudsman, and you can expect some compensation.

Every company featured on Eco Experts is accredited by the CPS. Or, you can find any more on the FENSA register or the CERTASS register.

If you want to get free quotes from these trusted experts, just complete this form.

Jonathan Whiting
Jonathan Whiting

An eco hero with a head for numbers, Jon’s data visualisation skills are legendary. Whether it’s determining what countries will survive climate change or the animals most at risk from it, he has the planet’s best interests at heart.

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