Jennifer Sheahan: "Check first with your local planning authority for any restrictions that may apply to where you put your windows and what style or colour they can be." Picture: Moya Nolan

You've chosen your window materials and types  — now let’s dive into the various styles and placement of windows in your home. 

The phrase “oh you must get sash windows” gets thrown around with abandon, but to be honest, when I first bought my home I didn't even know what sash windows were. I looked into it and quickly retreated when I encountered the baffling variety of styles available. 

I did what I often recommend doing — look at your neighbours and keep your style consistent. For me, that involved a one-over-two which simply means one window pane on top of two window panes. 

I’ve since learned much more and it’s knowledge worth knowing as windows are a central style element of any home. For the sake of brevity I’ll stick to styles popular in Ireland. 

Check first with your local planning authority for any restrictions that may apply to where you put your windows and what style or colour they can be.

Let’s start with sash windows, as they’re popular for good reason — they’re beautiful. They first appeared around the 17th century in either England, France, or the Netherlands, depending on who you’re talking to.

 Sash windows are effectively vertical sliding windows where usually the upper window pane is positioned over the lower window pane, such that the lower one can slide up behind the upper one. 

This mechanism is a great space-saver, as you don’t have to swing your windows wide open, and it’s also good for keeping rain (mostly) out (should you need to open your windows while it’s raining). 

Sash windows went through a few style eras — the Georgian sash windows had six panes in each of the upper and lower windows, and this remains very popular. 

In the Victorian era, glassmaking evolved significantly and larger windows with less ornate designs sprung up. 

More recently, sash windows have experienced a revival due to innovations in window frame materials — traditional timber frames and pulley mechanisms frequently required repair, whereas modern timber and sliding mechanisms work seamlessly. 

You can even get quite realistic-looking PVC wood-effect sash windows — have a look before committing to ensure you are happy with the faux effect. 

Multi-pane sash windows work best in older period homes or cottages. Sash windows with large, single panes and minimalist frames are a more fitting choice for modern homes.

Bay windows became popular in British homes during the Renaissance. They usually comprise three window panes set at roughly 45 degrees to each other and extending outwards from the exterior wall. 

They are wonderful for creating extra space — both the illusion of it and some actual additional space — and at letting in maximum light. 

Bay windows are most often associated with Victorian-style homes, although the style can be adapted to suit any home. For a very modern look, the window pane itself can even be curved — although this is expensive and many will argue there is a greater risk of leaking. 

Bay windows are usually downstairs in living rooms, where all sorts of Instagramable window seats can be added to them, but they can also be added upstairs (here they are called Oriel windows).

Transoms are simply that fixed pane of glass above a door, and sidelights are the ones to either side of a door. 

Transom windows are often rectangular but are sometimes arch-shaped which is often seen in Georgian, Victorian, and Edwardian homes, with varying degrees of flamboyance. 

Often seen around front doors, but also frequently around internal doors, transom and sidelight windows are purely there to let light through the home. 

Originally, their purpose was to allow ventilation without having to open the door, however, these days they are usually not designed to open. 

These are just one type of fixed window that are popular in modern homes — long horizontal windows are often now seen above kitchen cabinets to maximise light without compromising on space. 

Large fixed windows on the landing or stair return are also popular, and sometimes round or even more unusual shapes like hexagonal windows are used to add flair to a home.

Window dressings such as curtains or blinds — or even stained glass, etched glass, or one-way reflective coatings — can be added to sidelights or other fixed windows to retain privacy and add a unique design element to your home.

Most popular in modern homes, casement windows are those that open with a hinge on one side. These can be combined to form a variety of styles — for instance, my one-over-two style which was popular in cottages in the early 20th century. 

Rectangular casement windows in various combinations are seen in 20th-century styles such as art deco, mid-century, brutalist, and modern. 

There are no hard and fast rules for how you should design your casement window combination — instead,  consider what you need from your window. 

Which section needs to open and which can remain closed? How can you best bring light into that area? Do you want a more ornate style with multiple panels and designs, or would one large modern pane look better?

The golden ratio (1.61) is a number found in nature that is heavily used in architecture. It would take a whole other article to cover it fully but put simply, the golden ratio (also called the “divine proportion”) is a sequence of numbers that is used to analyse the proportion of objects relative to one another. 

Given its ubiquity in nature, this proportion is believed to be most pleasing to the eye and therefore became popular in architectural design. This relates to two things regarding windows —  their size and their placement. 

Typically, window sizes where one side is roughly 1.61 times longer than the other are thought to be the best proportion — for instance, if the window is one metre wide it should be about 1.61 metres long, or vice-versa. 

While the final decision on window size will include many other factors such as space and planning, it is one rule of thumb that may help. 

Similarly, considering the position of windows in proportion to the overall facade of the house will theoretically result in an aesthetically pleasing exterior. 

In practice, I prefer putting in the largest windows possible to let light work its magic on my interiors!

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