Without a doubt one of the biggest purchases in a homebuilding project, deciding on window styles can make or break your house design.
Our facades are often more window than wall these days, so it is highly important to take into account the thermal performance and energy efficiency, not just how much natural light it will bring to the table.
So whatever your project, the style of window you choose makes a huge impact on the overall appearance of the building and can influence how you interact with different rooms — research is key. You should consider:
- Design: Will your windows be classic and traditional, or sleek and contemporary?
- Style: Find out about the different types of casements and the what the styles bring to the table
- Material: Our material guide that compares cost, durability and style
- Glazing: Thermal performance and energy efficiency are now high of the priority list for many selfbuilders and renovators
- Costs: Take a look at our advice on comparing between quotes
- Ordering: Think about how to order and how the lead-in times will affect your project
The positioning of windows will be informed and influenced by room layouts and the shape of the house itself but the shape and type of the windows themselves should be taken into serious consideration when deciding on the exterior and interior finishes.
For instance, a contemporary, single-storey house is improved by similarly narrow, vertical windows but old cottages look odd with large glazed openings forced into thick stone walls.
The golden ratio – as developed in classical architecture – is still used today as a general rule of thumb. The ratio proportions are 1:1:618 meaning a vertical sash window at 800mm wide should be 1,300mm tall.
Traditional Window Styles
If you’re building in period style or renovating an older home, choosing appropriate materials and styles is a must — in most cases this will mean timber casements or sashes. Modern window companies can replicate older styles where possible but unfortunately you cannot effectively replicate wood grain with PVCu, although there are a few manufacturers might try, (skip to Choosing materials).
Small casement windows are associated with cottages and there are some stunning offerings out there, but a trickier style to replicate with double glazing is a Georgian and early Victorian era multi-pan sliding sash as achieving glazing bars which are as elegant with modern methods is tough.
Window Styles for Contemporary Homes
As glazing became progressively cheaper and easier to work with over the centuries, the size of our windows grew. By the time of the advent of modernism in the early 20th century, simplicity became the watchword: minimising not just the amount of framing but also the frame width itself.
You could consider the more modern the house or build-style, the bigger and cleaner the glazing should be. Timber will soften a rendered exterior of a modern home, while aluminium windows are perfect for minimalist styles.
Open-out Casement Windows
A traditional British option (historically and in the 20th century), open-out casements are available in a variety of formats. Choose split casements for cottage-style designs and small glazed units to mimic ‘Georgian style’. In contemporary house styles, side hung and awning formations work well as there is no mullion to interrupt the view.
- Large casements tend to be the cheapest
- Costs tend to be lower because they are made in modular, standard sizes
- Great for ventilating rooms but as they can open wide, this might cause concern for those with small children or animals
Types of Casement-style Windows
1. Side Hung: The most recognisable casement. It is hinged at the side for easy opening
2. Top Light: A fixed pane divided from a narrow glazed top-hinged casement
3. Sliding Folding: The sash is hinged so that it folds, increasing the area of openable window to an almost clear expanse
4. Top Hung/ Awning: A casement window that is hinged at the top. Perfect for wet climates as it blocks out rain
5. Bottom Hung/ Hopper: A casement window that is hinged at the bottom. most commonly used in basement
6. Centre Hinge/ Pivot: A window that is hinged in the centre to allow for a wider opening, it requires less of a swinging clearance
The centre hinge/pivot casement in this industrial loft conversion completes the interior scheme beautifully (image: Mereway Kitchens)
Tilt and Turn Windows
Continental-style tilt and turn windows open inwards, and look best on modern designs. The ‘tilt’ option provides ventilation with security.
- They are typically made to order, increasing the cost
- Great for smaller rooms where saving space is a priority
Fixed windows are just that, fixed, so they don’t open out or let in any ventilation. However, they do maximise opportunities for natural light throughout a home. As they don’t need to be made to incorporate a opening mechanism, there are endless designs and styles to play around with.
- Provides light in wasted spaces
- Can create interesting designs
- Usually the cheapest style of window
Sash windows are essential when renovating or replicating Georgian and Victorian housing, still widely used on traditional-style new builds. Sizes are typically not standard but windows need to be in proportion to the house, so are often bespoke.
- Timber sash windows require maintenance
- Typically have vertical tracks so won’t fill up with leaves and detritus
A bay window projects outward from the face of a building, forming a recess within a room. A Bay window can span more than one storey, as seen in many Victorian and Edwardian homes, and can be used in self-builds to create window seats and breakfast nooks. There are different types of styles of bay windows including:
- Canted. This means the window is formed of straight front and angled sides.
- Bow. Where the window structure is architecturally curved.
- Oriel. Starting above ground level, an oriel window is supported by corbels or brackets as it jetties out from the main walls of a building.
Rooflights, skylights and roof lanterns
Introducing windows into the roof can work wonders in renovations, extensions and conversions to bring in natural light where conventional windows can’t be installed. Fixed windows that follow the roofline are typically known as skylights, while rooflights tend to open. Roof lanterns are common in orangery-style extensions and sunrooms as they replace a solid roof.
- Rooflights are great for ‘rooms in the roof’ in loft conversions or one-and-a-half storey homes, which are steadily becoming more popular options among self-builders with height restrictions.
- Skylights are increasingly seen in terraced houses with side return extensions, providing light deeper into the floorplan
- Roof lanterns offer a greater opportunity to introduce the maximum amount of light and help to achieve the illusion of extra head-height in extensions with flat roofs.
High-level windows that are sometimes used to retain privacy but increase natural light or ventilation. In modern energy efficient houses, clerestory windows have been used in solar gain strategy and paired with stone, brick or concrete. In hotter parts of the day the elevated window position gains heat and essentially uses the structure below as a heat bank.
- Let in extra light and ventilation
- Great for rooms with high ceilings
An architecturally impressive way to flood a home with light, glazed gables don’t have to break the budget on a self build or extension if planned into the design early on.
- Add ‘wow factor’ to any room
- Can suit traditional cottages just as well as modern designs
It’s useful to rank window costs on a square metre basis. Suppliers tend to dislike this because you don’t buy windows by the square metre: they are priced individually and generally the larger the actual window, the less it costs per square metre, so reducing a window range down to a square metre price is never going to produce an accurate pricing method. But from a comparison point of view, it’s a very useful tool.
Take the total amount quoted to supply windows and divide by the area of the window openings to derive the square metre rates.
See below for a cost break-down of different window frame materials.
Timber’s main selling point is the feel and authenticity it offers to period-style homes: there is no real replacement for the warmth of traditional timber windows.
- Nothing can beat the tactility and detailing of a timber framed window
- Softwood is popular among those on a limited budget as they are the cheapest option if glazed and decorated on site
- Can be stained, but are usually painted
- Suites both contemporary and traditional style homes
- On-site glazing carries a risk of double-glazing failure (i.e. misted units)
- Factory glazing lowers the risk but costs more
- Softwood requires repainting every few years
Best Softwoods to Choose
Douglas fir is a very stable, durable softwood while European Redwood (also known as Scots Pine) is less prone to dimensional change and movement.
- Have a tighter grain than softwoods, making them more stable and durable
- Can be treated to be further stabilised
- Most popular on traditional-style homes
- Usually stained
Hardwood Cons: It’s expensive — anything up to four times the cost of softwood
- Softwood: £6,000-£15,000, less if ‘DIYed’ on site
- Hardwood: Between £8,000 and £20,000
One of the most popular materials for windows in contemporary homes, aluminium windows can offer slim sightlines or a frameless appearance.
(MORE: Aluminium Windows: How to Choose)
PVCu windows long reigned supreme as the dominant material for replacement windows and for good reason. A quick and easy option, plastic windows are low-maintenance and cheap.
- Cheapest overall although costs var with quality
- Can look cheap
- Can reduce the value of period homes
- Not easy to repair
- Doors can be weak
- £5,000-£15,000 for a one-off house
If you’re struggling with the choice of materials, there is a compromise — the so-called composite systems that mix different framing materials inside and out.
- Best of both worlds as they usually consist of timber windows with a weather-proof capping, such as aluminium strips or plastic
- Can withstand harsh climates (widely used in such as Canada and Sweden)
- Great for triple-glazing
- Complement modern designs
- Low maintenance but offer the warmth of timber
- Unlikely to be made to standard UK sizes if ordered from the Continent
- Between £10,000 and £25,000 — expect to pay 25% more for triple glazing
- Popular among contemporary-style homes but increasingly popular in period properties (particularly for Belgian doors)
- GRP (fibreglass) can create a strong load-bearing frame
- GRB can be supplied in any colour
- Low maintenance
- Produce finer frames
- Not as thermally efficient as wood
- Can be expensive
- Between £8,000 and £20,000
On-site double glazing is the cheapest option for DIY self-builders, usually done with softwood frames which are then painted on site. Slow and time consuming, most suppliers are moving away from on-site glazing for new installations.
New methods in factory double glazing mean that many windows can be clipped into templates from inside, thus streamlining the installation. However, it is more expensive than on-site glazing.
Low-emissivity or ‘low-E’ glass (as it is more commonly known) is a type of glazing designed specifically to prevent heat escaping through windows. Low-E double glazing meets Building Regulations in the UK (such as Part L1B in England) for replacement windows and new windows for extensions.
- Can reduce heat loss by at least as four or five times compared with single glazing
- Solar control glass can be specified to educe excessive solar gain in the summer for areas of the home susceptible to overheating
Once only popular in low-energy homes, triple glazing is rapidly becoming a standard solution for today’s window suppliers.
- Excellent comfort levels as it evens our temperature profiles of rooms
- Great for noise reduction for homes near busy roads etc.
- Helps minimise overheating
- Some suppliers offer special coatings that will allow solar gain when required (i.e. in winter)
However, the issue is really around where to put it, with most experts agreeing that it’s near-essential on north-facing elevations with lots of glazing and to be generally avoided on south-facing elevations.
This very much depends on whether you’re opting for off-the-shelf windows or bespoke products, and can also differ from company to company.
A general lead time would be around 12 weeks, however, it goes without saying that bespoke windows will inevitably carry longer lead times. It is best to not order too early on in the project in case amendments to the building design or aperture sizes occur.
How Can I Increase the Amount of Natural Light in My Home?
When you first step into a new home or freshly completed extension, the first thing people notice is whether it feels light and airy, or dark and dingy. This is impacted by the amount of natural light provided by window design.
Window design will obviously be near the top of your list when designing the exterior facade of a new house, but this also applies to extending existing homes, too. The development of super-wide bifold and sliding doors in recent years has been something of a game changer for maximising natural light in homes. As have roof lights where rooms struggle to achieve the same levels of brightness due to the floorplan (say, in a bathroom or living room).
Considering how an extension will affect the existing rooms is key in the longevity of your enjoyment in the new space so take the time to study where light will fall throughout the day and when you will utilise each room. Think about adding small side windows or clerestory windows to compensate.
For new homes, the luxury is the floorplan is freshly designed to suit each space’s needs, but be weary of overheating in rooms with too much glazing. As anyone who has been in a conservatory tacked onto the back of a house will attest, simply incorporating a lot of glazing isn’t necessarily a recipe for a comfortable interior.
Editor’s note: If you’re after information to help choose a windows and/or door vendor that’s right for you, fill in the questionnaire below and we can provide you with information from a variety of vendors for free: