Georgian Windows: How to Recognise and Restore Them

Georgian windows are timber sash windows from roughly 1714 to 1830, classically six panes over six, with very slim glazing bars, no horns on the sashes and thin, rippled crown glass. Most originals can be repaired rather than replaced, keeping the old glass.

Of all Georgian house features, the sash window is one of the most easily lost or altered. In our workshop at Crossley Mills in Honley we restore timber sash windows for homes across Yorkshire. This guide shows how to recognise a Georgian window, how it differs from a Victorian one, and how we restore it without losing what makes it valuable.

What are Georgian style windows?

Georgian architecture is the name given to the styles current between 1714 and 1830, named after the four King Georges who reigned in that time (Wikipedia, Georgian architecture). The defining window of the period is the vertical sliding sash. It was already developed by the 1670s and became very widespread for the large, regularly placed windows of Georgian houses.

The classic arrangement is three panes across by two up in each of the two sashes, giving a "six over six" window, though Wikipedia notes this is by no means a fixed rule (Wikipedia, Sash window). A guide for owners published by Wychavon District Council records six over six alongside other patterns such as three over six and eight over eight (Wychavon District Council, History of Windows and Glass).

Proportion matters as much as pattern. Georgian design used simple mathematical ratios to set the height of a window in relation to its width, and regular, symmetrical housefronts were highly valued (Wikipedia). That is why Georgian sash windows look tall and calm, and why one badly proportioned replacement stands out on an otherwise regular front.

How do you recognise Georgian windows?

Stand outside and then inside, and work through this checklist. No single point proves a date, but three or four together are a strong sign.

1. Small panes in a grid. Six over six is the classic, but other patterns were used.
2. Thin glazing bars. The Wychavon guide says the width of glazing bars slowly reduced through the 18th century, and by the end of the century the bars on fine sashes were as little as 10mm wide (Wychavon).
3. No horns. Look at the bottom corners of the upper sash. If the side pieces run straight into the meeting rail with no little projection below it, that fits a Georgian date.
4. Moulding on the inside. The same guide notes that 18th-century internal mouldings were of the "lamb's tongue" type. Earlier sashes often had an ovolo moulding.
5. Rippled glass. Look along the pane at an angle. Old glass shows gentle waves and distorted reflections; modern float glass is flat and featureless.
6. How the frame sits in the wall. In London, building acts of 1709 and 1774 pushed sash boxes back from the face of the wall and then behind the masonry. The Wychavon guide warns that the position of the box is not a reliable way of dating a building, so treat it as a clue only.

What are the key differences between Victorian and Georgian windows?

Much of the difference comes down to glass. The Wychavon guide explains that improved manufacture made glass less expensive from 1837, and by the middle of the 19th century most windows had one central glazing bar or none at all. Horns were then introduced to make up for the heavier glass and the loss of the bars (Wychavon).

Feature	Georgian windows (1714–1830)	Victorian windows (1837–1901)
Pane pattern	Many small panes, classically six over six	Larger panes; later often two over two or one over one
Glazing bars	Many bars, becoming very slim on fine sashes by the late 1700s	By mid-century, one central bar or none
Horns	None	Common, to strengthen the corner joints of the sash
Glass	Crown glass, thin with a gentle ripple	Cheaper cylinder and plate glass in bigger sheets
Overall look	Light, fine grid across the opening	Fewer bars, more open glass

One thing to watch: many Georgian houses had their glazing bars taken out in the 19th century. Wikipedia notes that glazing bars were removed from the windows of thousands of older buildings in favour of large panes of plate glass, and that later restoration often put them back (Wikipedia, Muntin). So a house can be Georgian even if its sashes now look Victorian. The age of the building and the age of its windows are two separate questions.

Why does the old glass in Georgian windows matter?

According to the Wychavon guide, crown glass was first recorded in 1674 and remained standard until the 1830s. It was made by spinning a blown bubble of glass into a disc, then cutting panes from it. That is part of why Georgian panes are small. The guide describes old glass as having a "rippling transparent vitality and greenish hue", and says old cylinder and crown glass are irreplaceable, thin and easily broken, and should not be removed from their frames unless absolutely necessary (Wychavon).

SPAB says the same about the whole window: historic sash windows, including their glass, are integral to many old buildings and should almost always be kept, not replaced (SPAB, Sash window maintenance). In practice, we repair around the glass wherever we can. If a pane has to come out, the putty should be softened carefully and each pane labelled so it goes back into the same opening.

How do we restore Georgian sash windows?

Restoring Georgian sash windows follows the same steps as any sash repair, with more care over the fine joinery. Our step-by-step guide on how to restore a sash window covers the full process. In short:

• Survey first. We check every sash, the box frame, the cill and the cords, and note which glass is old.
• Free the sashes. SPAB warns against forcing a sash that will not move, because this often causes damage. Common causes of sticking include paint build-up, broken cords or a distorted bead (SPAB).
• Repair the timber. Rotten sections of cills, bottom rails and meeting rails are cut out and spliced with new timber matched to the original profile.
• Repair or copy glazing bars. A broken bar can often be pieced in. Where a bar is missing, we make a new one to match the surviving moulding exactly, so it is as slim as its neighbours.
• Re-cord and rebalance. SPAB advises that if one cord breaks, it is worth replacing all the cords on that window, and that weights must be correctly sized so sashes do not rise or drop by themselves.
• Reputty and paint. New putty, then thin coats of paint. SPAB suggests painting only very slightly onto the glass, otherwise the glazing beads look too wide.
• Draught-proof. SPAB notes that good draughtproofing will cure draughts and rattles caused by wear. Our sash window draught proofing service covers this step.

All of this is part of our sash window restoration service, carried out by hand at the bench in Honley.

Our rule of thumb: repair or replace?

Our rule of thumb is simple: if the box frame is sound and the glazing bars are mostly intact, we repair the window rather than replace it. A rotten cill, a soft bottom rail or a broken cord is a normal repair, not a reason for a new window.

We only recommend a new sash when both sash corners and the meeting rail have rotted through, or when the glazing bars have been lost and replaced with something clumsy. Even then, we make the new sash to copy the old one: the same bar width, the same moulding, no horns, and the old glass reused where it survives. We keep the original box frame wherever we can.

Georgian windows in Yorkshire homes

Wikipedia lists the Georgian cities of the British Isles as Edinburgh, Bath, Dublin and London, and, to a lesser extent, York and Bristol (Wikipedia). We cover York and Wakefield, where Georgian house features such as original sashes can survive under many layers of paint.

Yorkshire also has its own window. The Wychavon guide mentions a less common sideways-sliding type called a Yorkshire sash, and SPAB calls the "Yorkshire light" a notable variation where the sash moves sideways without weights.

Weather is the other local factor. In the wet, exposed Pennine country of the Colne and Holme valleys, cills and bottom rails on the weather side stay damp for long spells. Keeping the paint and putty in good order matters more here than almost anything else.

Are Georgian style windows more expensive?

New Georgian-style sashes usually cost more to make than plain one-over-one sashes. Every glazing bar needs its own moulding and joints, and every pane has to be cut, bedded and puttied. Slim, true glazing bars take more bench time than a single sheet of glass.

Repair costs depend on the condition of the timber, how many panes are cracked, and how much paint needs stripping. We do not publish a standard price because every window is different. Our guide to what affects the cost of sash window restoration explains the main factors.

Can you replace windows with Georgian style?

Yes, but check the rules first. The Planning Portal says you do not usually need planning permission for repairs and maintenance, or for new windows of a similar appearance to those used in the construction of the house. It also says a listed building needs listed building consent for any significant works, inside or out, and that conservation areas may have extra restrictions. Some councils have also removed these rights with an Article 4 Direction (Planning Portal, Doors and windows). This guidance covers houses in England, and whether a new glazing pattern counts as a similar appearance is for your council to judge. Always check with your local planning authority or conservation officer before you start.

If you are putting Georgian-style windows back into a house that lost them, base the design on evidence: a surviving original window, old photographs, or neighbouring houses of the same date. Get the bar width and pane proportions right, and leave off the horns. Glazing upgrades can be added in some cases, and we can advise on what suits your house before you decide. For a listed building, agree any change with your conservation officer first.

Frequently asked questions

How can I tell if my windows are Georgian?

Look for small panes in a grid, often six over six, very slim glazing bars and no horns at the bottom of the upper sash. Old glass with a gentle ripple is another good sign. Check the building's date too, because many Georgian houses had their sashes replaced or altered in the 19th century.

Do Georgian windows have horns?

Original Georgian sashes do not have horns. Horns came in during the 19th century, when heavier sheets of glass and fewer glazing bars put more strain on the sash joints. If a Georgian house has sashes with horns, they are most likely later replacements, and that is worth knowing before any repair.

Can original Georgian glass be kept during restoration?

Yes, in most cases. We carry out timber repairs with the glass left in place wherever possible. If a pane must come out, the putty is softened carefully and the pane is labelled so it returns to the same opening. Old crown glass is thin and easily broken, so it needs patient handling.

Are Georgian sash windows draughty?

They can be when worn, but that is usually fixable. Worn beads, gaps at the meeting rails and loose sashes cause most draughts and rattles. Draught-proofing fitted into new beads, together with re-cording and small timber repairs, makes a big difference while keeping the original sashes and glass.

Sources

• Wychavon District Council: History of Windows and Glass, a guide for owners and occupiers (2007)
• Society for the Protection of Ancient Buildings: Sash window maintenance
• Planning Portal: Doors and windows, planning permission
• Wikipedia: Georgian architecture
• Wikipedia: Sash window
• Wikipedia: Muntin