Heritage rose installation from outside

If you’re thinking about replacing your sash windows, you’ll want as much information as possible. As with any specialist product, a lot of the terminology will be unknown to the majority of people. When you think of a window, you probably think it only consists of the frame and the glass. Add some handles and hinges, and that’s about it. When you hear terms such as sash horns, mullions, and astragal bars, you’d be forgiven for thinking you were hearing a different language.

At the Rose Collection, we want the best for all our customers. When a customer feels like they understand a product, they are usually happier with their purchase. To help you to understand some of the more unusual sash window terminology we’ve compiled a handy sash window jargon guide to ensure you’re fully informed.

Sash horns

Originally used in timber sash windows to strengthen the joints, they are a distinctive part of a sash window’s appearance. Sash windows often feature in the Rose Collection as either run-through sash horns which are an integral part of the window or clip-on sash horns for a cost-effective alternative.

Transoms and mullions

A transom is a vertical beam that divides a window into sections. A mullion is its horizontal counterpart. Originally used to support separate glass panes, they are now commonly used to replicate the traditional heritage style.

Astragal/Georgian bars

The specific name for the thin transoms and mullions used in heritage windows. Originally used in the Georgian era, they are a common feature in many period property windows.

Meeting stile and rail

Sections of the window frame that support the structure.


The sections of a window which are joined together to create the frame.

Window furniture

Umbrella term including all locks, handles, hinges etc.

We hope that our sash window jargon guide is helpful to ensure you make an informed decision. If you’d like more information on the Rose Collection call 01234 712 657 or contact us online.