Often referred to as the eyes of a house, traditional windows play a vital role in defining the character of a period property. Key components of overall appearance, they are inextricably linked with architectural style and it is often through examining windows that you can determine the age of a building.
Usually made from wood or metal, period windows are vulnerable to decay if not properly maintained and if you are renovating you might find you need to replace them. This guide will help you choose the best windows for your period home.
Find out more about windows on our dedicated pages.
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Original windows were made using traditional techniques that are hard to imitate today due to modern building regulations, and their unnecessary replacement erodes the character of period homes. This means it’s vital that very effort is made to preserve and maintain original windows.
Even if your windows look beyond repair – having succumbed to rot and broken glass – you’d be surprised at what can be achieved through expert restoration.
If your windows do not require structural repair, they can still be significantly improved. ‘Draught-proofing and repairing original windows can dramatically improve functionality, security and efficiency at a fraction of the cost of replacement,’ says Richard Dollar, managing director of The Sash Window Workshop (opens in new tab).
Additionally, the whole-life environmental costs of replacement will be much greater than repairing the architectural treasures that already exist.
Single-glazed windows are often replaced with double glazing due to a fear of inefficiency. But you are unlikely to ever see a return on fuel bills, while the originals could have been upgraded. However, if they are too rotten to repair, inappropriate modern designs are present, or you are extending, you need to source authentic-looking new designs.
Use our guides, too, to find out:
- How to restore your original sash windows
- How to repair and maintain leaded windows
- How to restore metal windows
Windows DIY Maintenance check
While larger jobs and repairs require professional skills, there are smaller maintenance tasks you can carry out to keep your windows in good condition.
- Fixing putty - The main damage to putty is caused by sunlight. Depending on the severity of the damage, putty will need to be repaired by filling the gaps, or replacing it. To replace, remove old putty using a scraper and allow the exposed wood to dry out. Then prime the wood with paint, allow to dry and replace the putty.
- Draught-proofing – Applying DIY draught-proofing is an easy fix for a common problem in period homes. Use draught strips, or brush seals for sash windows, which are available from DIY stores.
- Repainting – Regular painting of windows is vital as poorly maintained and unprotected timber will rot and swell. Make sure you prepare the surfaces, sanding down to remove all loose paint and stripping paint layers using gel-type strippers. Natural linseed oil paint offers good protection
- Oiling hinges and sashes – Check hinges, locks and catches. Where necessary, realign, ease, repair and lubricate them. Apply beeswax or tallow to the edges of sashes to help them run.
How much do new windows cost?
Windows are priced individually, but for the purposes of working out rough costs over large areas, these estimates are presented in metre square.
- Softwood casements: from £200 to £350 per m2
- Hardwood casements: from £350 to £500 per m2
- Timber sash windows: from £800 to £3,000 per m2
- Metal windows: from £300 to £600 per m2
How can I upgrade existing windows?
Old windows inevitably face threats such as warping, rotting, sticking, chipping and corrosion.
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In addition, many homeowners complain of draughts and high energy bills. But before automatically replacing, look at measures to repair and upgrade them
Energy is lost through windows in two ways: by heat passing through the glass and by warm air escaping though gaps in and around the frames.
‘If wood windows are in a reasonable condition, they can be draughtproofed and repaired,’ says Richard Dollar, managing director of The Sash Window Workshop (opens in new tab). ‘This improves functionality, security and efficiency at a fraction of the cost of replacement.’
Occasionally, individual panes of existing windows can also be substituted for insulated glass units (IGUs).
To further improve performance, look at fitting secondary glazing, which involves adding a slimline pane of aluminium-frame glass to your existing windows. It’s a cost-effective, efficient way to insulate and sound-proof windows without impacting on their character. Try a company that produces discreet bespoke designs, such as Storm (opens in new tab).
What are the different window styles?
The most familiar window types in period homes are side-hung casements – wood or metal – which swing open like a door, and vertical sliding timber sashes, which consist of two frames or ‘sashes’, each with panes of glass held together by wooden glazing bars, which slide vertically in grooves and are held open by weights and pulleys concealed in a timber box frame (although early sashes were held open by pegs).
Manufacturing techniques developed over the centuries to allow for larger glass sections, which were cheaper and more readily available, so early windows had small panes and later windows usually had larger panes.
The glazing is as important as the frame, and imperfect original glass adds its own unique character. Stained glass panes are sometimes present.
Medieval and Tudor windows
Glass was very expensive during the Tudor period, to the extent that when people moved they would often take it with them. Rural properties and those of more humble backgrounds tended to have wooden or stone openings that could be covered with boards, and later shutters.
When glass was used in windows, they usually featured metal frames with leaded glass inserted into stone or wooden openings.
Metal windows continued to be used throughout all eras, although saw a notable resurgence during the Arts and Crafts period as design became increasingly influenced by medieval styles and craftsmanship.
Comprised of two individual sashes, each with panes of glass held in place by wooden glazing bars, sash windows slide vertically in grooves, which are operated by weights and pulleys concealed in a timber box frame. Earlier Georgian designs were typically in eight-over-eight or six-over-six pane configurations.
If you live in a Victorian home you are likely to have sash windows or casement windows – most likely made from timber. Mock Tudor homes were also popular in the Victorian era so leaded lights between stone mullions may be present.
All Victorian windows were single-glazed so many were ripped out in post-war renovation projects and replaced with double glazing. If you are lucky enough to still have the original windows, always see if repair is an option before replacement, then upgrade with secondary glazing to improve the efficiency.
1930s style windows
The 1930s housing boom created a large stock of homes that still stand today. Bay windows are common on 1930s homes and steel was used widely as shown by the popular Crittal-style windows of this time. The Art Deco movement was in full swing so unusual shapes and ornate glasswork were commonplace in 1930s windows too.
Sash window types
- Sash windows reigned supreme from the Georgian to Victorian eras, first in eight-over-eight or six-over-six pane configurations , and eventually two-over-two or one-over-one. Sometimes multiple panes were used in the upper sash, with a large pane in the bottom half
- In the Victorian era, sash horns were introduced on the bottom edges of upper sashes to take the additional strain caused by the lack of glazing bars and heavy glass panes.
- Bay windows were hugely popular in the Victorian era.
Casement window types
- In Tudor homes, small ‘lights’ in a leaded lattice framework – usually diamonds or rectangles – set into stone or timber openings, are authentic.
- Casement windows continued to be used in small, rural dwellings and in the late-18th and early-19th century. Later casements increasingly had larger panes and timber glazing bars.
- The Victorians often adorned the upper halves of their windows with elaborate glazing bar designs and shaped windows heads, such as Gothic arches.
- In the 1930s, steel Crittal-style windows were widely used.
What are the benefits of timber windows?
‘Timber windows offer a huge range of benefits beyond style and design flexibility, such as thermal performance and a long life,’ says Tony Pell, senior product manager at Jeld-Wen (opens in new tab).
There are two main types of timber used in windows: softwood and hardwood. Windows made of hardwood, such as oak, are the more expensive option, due to the fact that the trees are slower growing. However, its tighter grain offers more stability within the wood, providing it with a typical lifespan of around 60 years.
Softwood, such as Douglas fir, carries a lower price tag and money can also be saved by glazing on site. Yet, the lower price is reflected in its shorter longevity, which varies depending on the type of wood used.
Two other options that are rapidly gaining popularity are engineered and modified timber. In engineered timber, sections of individually weaker wood are glued together to create a stronger single piece, while modified timber has been treated with chemicals or exposed to high heat to achieve the same result.
Depending on the specific glue, chemical types or heat used, engineered and modified timber can be up to 60 per cent stronger than the alternatives, offering a lifespan of up to 80 years. As a result, both types of wood are being increasingly specified by the construction supply chain as they offer a desirable alternative to uPVC and metal, providing many of the benefits of hardwood at a lower price point.
What are the benefits of metal windows?
The first metal windows were made from wrought iron by medieval blacksmiths, but metal casement windows had a revival during the Arts and Crafts movement, towards the end of the Victorian era, and in the 1930s, when Crittall styles were popular. Previously thought of as cold and inefficient, metal windows are now a thermally efficient choice thanks to modern technology.
Aluminium, bronze and steel all offer exceptional stability and strength while being relatively low maintenance. Metal windows are competitively priced, with hardwood designs.
How to get the windows' design right
With period properties, like for like is always best. If you are looking to rectify inappropriate windows, study nearby properties from the same era to ensure the style of window matches the rest of the building. Proportion, glazing bars and the glass itself all contribute to the character and overall appearance of a window, so all components must be addressed when thinking about replacements.
‘All aesthetic aspects should be considered, including selecting the right timbers, colours and decorative options, while also taking into account neighbouring properties so your home is in-keeping with its surroundings,’ says Sean Crane, head of surveying at Jack Brunsdon. If in doubt, ask your local conservation officer for advice.
Do I need planning permission to change my windows?
Usually replacing period windows with like-for-like replicas will not require permission, but it may be needed where permitted development rights are restricted.
If you live in a Conservation Area, planners can be very particular about the new replacements being as close to identical as possible, and if there is an Article 4 directive, you will need to apply for permission.
Listed building consent is always required to replace windows in listed properties. To gain permission to replace any listed windows or doors, homeowners need to prove that the existing ones are beyond repair or that they are experiencing too much heat loss.
Take advice from a reputable company that has experience in window and door design and construction, and remember that planning officers can also advise on what is and is not acceptable.
Do new windows need to meet building regulations?
‘For complete new windows, the company making and installing them must be registered with FENSA (opens in new tab),’ says Richard from The Sash Window Workshop (opens in new tab).
‘If your current windows have trickle vents – small ventilation holes in the frame – you will need to ensure that the new windows have them or there are alternative sources of background ventilation.
‘Windows near floor level must contain safety glass (toughened or laminated) and must include the relevant safety mark clearly visible.
‘Once the work has been carried out you should receive a FENSA certificate through the post, which you will need if you sell the property in the future.’
To meet building regulations the amount of heat that can pass through the glass and framework is measured as a U-value and this has an effect on the efficiency of the window. For a listed building there is some flexibility in the U-value, in the interest of preserving traditional character.
New sashes or casements fitted into existing frames are classed as refurbishment, and so this work does not require certification. Find out what you need to know about fitting new windows.
Do I need double glazing?
In order to comply with building regulations, most new windows are fitted with double glazing for increased energy efficiency.
However, double glazing can cause issues when it comes to replicating authentic single-glazed windows. This is particularly the case for designs with elegant timber bars or leading, as both options traditionally involve joining together multiple smaller panes.
To replicate this on new leaded double-glazed windows, leaded detailing is applied to the surface of the glass for an authentic appearance. Timber bars are traditionally widened to accommodate double glazing, although this can impact on their elegance. Ultra-thin double-glazing units have now been developed, however, that can fit within original frames; this means slimmer, more authentic designs are now possible for listed homes or those in conservation areas, without compromising on efficiency.
The glazing industry is continually innovating to improve the issue, which means that double glazing units are being developed that are thinner than ever, such as Slimlite (opens in new tab), allowing for more elegant designs.
Triple glazing is another option (opens in new tab) for new windows that will enhance comfort inside. The sections will look too thick for authentic windows, but it can be a good solution for casements on some extensions, newer period-style houses and less historically important older homes.
Bespoke windows or off the shelf?
The most cost-effective option is to buy ready-made timber windows off the shelf. ‘Opt for made-to-measure windows if you can’t find what you’re after in standard sizes, or to address quirks or unusual shaped openings,’ says Tony Pell. ‘This also enables you to specify in-keeping double-glazed designs.’
More advice on old homes:
- How to strip and repaint original plaster mouldings
- House renovation: how much does it cost?
- How to extend an old house
Additional copy by Pippa Blenkinsop, Holly Reaney, Elizabeth Bailey and Paula Woods