All About Sash Windows

ABOVE: Restoring original sash windows is always a better option than replacing them. This Georgian farmhouse has been sensitively restored and extended, creating a family home that exudes character. (Read more about this renovation)

Why Choose Sash?

Not only do sash windows perfectly suit period homes, they are also ideal for the British climate.

Whether you are renovating, or building from scratch, a house of Georgian, Victorian or Edwardian style, then the chances are that you will have sash windows. This style of window is an enduring favourite for many and the lure of many period houses. However, sash windows are notoriously difficult to get right for both those self-building and renovating, in terms of spot-on design details and choosing the correct style of sash for your home’s era.

A sash window is made up of either one or two moveable ‘sashes’ (a frame that holds panes of glass, separated by ‘glazing bars’). Sash windows are opened by sliding the sashes either vertically or horizontally. The load of the sashes is balanced by weights, concealed within weight pockets in the frame. The weights are connected to the sashes by a cord which runs over a pulley wheel at the top of each frame, although spring balances are now sometimes used.

ABOVE (left-right): Six-over-six sash windows are typical of the Georgian era; Sash windows do not have to be standard in shape, as this pretty arched window from Scotts of Thrapston shows (01832 732366; scottsofthrapston.co.uk).

Which Design is Right for You?

Sash windows have been around for hundreds of years and designs have inevitably evolved over time.

While houses dating from the 1700s (some as early as late 1600s) up to those built in the 1920s usually had sash windows, their design varied quite dramatically, and it is important to bear this in mind.

Georgian architecture definitely favoured the sash window and developed it from a single moving sash – with the top previously being fixed – to two moving sashes. Oak was commonly the material of choice, with relatively thick glazing bars holding the small, delicate glass panes in place. As developments in glass manufacturing were made, larger panes began to appear, as did the recognisable six-over-six style of sash, with narrow glazing bars gaining popularity.

The Victorians loved highly decorated fittings and furnishings for their homes, and it was during this era that curved horns, latticework, leaded lights and arched heads appeared on sash window designs. The larger sashes tended to be on the ground floor, often in bays and with ornamental stone revels, whilst smaller sashes were reserved for the upper storeys.

The Edwardians often presented sash windows in bays and tended to fix an upper multi-pane, usually featuring six sashes, but use a single pane of glass in the lower sash.

The ‘Yorkshire sash’ slides open horizontally.

ABOVE (l-r): Refurbished sash window from Ventrolla (0800 027 7454, ventrolla.co.uk); Mumford & Wood, (01621 818155, mumfordwood.com).

Choosing Materials

Although timber is the most authentic material, there are alternatives.

Most experts agree that timber is the only material for sash windows, with PVCu neither suiting the style of window, nor the houses they are usually being fitted to. However, many people feel PVCu offers benefits, primarily in terms of the low levels of maintenance required in its upkeep.

Most companies who supply timber and PVCu recommend opting for white-painted timber-effect PVCu as opposed to plain in terms of appearance. It is also best to opt for windows with bead detail internally and externally to replicate a traditional look. PVCu windows are also available with putty line sashes and ovolo beading, integrated horn details and deep bottom rails.

If opting for timber, you will have the choice between softwood and hardwood. Softwood windows are cheaper, but require preservative treatments before they can be fitted, whilst hardwood contains tannins and other natural preservatives, making the windows naturally more durable. Sapele mahogany is one of the most commonly used hardwoods, whilst European redwood is typically used for softwood sash windows.

It is also possible to buy sash windows with a timber interior and a low-maintenance composite exterior — take a look at blackmillwork.co.uk.

Further reading:

• Sash Windows: Design Advice
• Sash Windows Explained
• How to Restore Sash Windows