Glazing has quickly become one of the most important considerations to make when designing your home.
Be it a complete self build or renovation, or an extension and remodel, the style of window you choose makes a huge impact of the overall appearance of the building.
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.
Matching House Design and Window Styles
Room layouts and the shape of the house will inform and influence the positioning of windows, but 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 (as below) but old cottages look odd with large glazed openings forced into thick stone walls.
The general rule of thumb is to ratio proportions to 1:1:618 (also known as the golden ratio). Developed in classical architecture, this ratio is still used today meaning a vertical sash window at 800mm wide should be 1,300mm tall.
If you’re building in period style or renovating a cottage, choosing appropriate materials and styles is a must — in most cases this will mean timber casements. 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.
Small casement windows are associated with cottages and there are some stunning offerings out there, but a tricker 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.
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 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.
What are the Different Window Styles?
A traditional British option (historically and in the 20th century), open-out casements are available in a variety of formats. Large casements tend to be the cheapest, but you can choose split casements for cottage-style designs, and small glazed units (‘Georgian style’). They are usually made in modular, standard sizes, keeping costs down.
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 basements.
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.
Tilt and Turn
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.
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.
What Material Should I Choose?
Plastic (PVCu) has dominated the new build and replacement window markets since the 1990s as a ‘fit and forget’ solution. Wrongly perceived as the environmentally unfriendly option, manufacturers are working hard to improve their reputation by using recycled plastic.
- Pros: It’s the cheapest overall option, though costs do vary enormously with quality. Most appealingly, it doesn’t require maintenance.
- Cons: PVCu can look cheap and reduce the value of period homes. It cannot be repaired easily, and doors can be a weak point.
- Cost: £5,000-£15,000 for a one-off house.
Nothing looks quite like a timber sash in either a traditional or modern home. The tactility and detailing of a timber framed window is, for most homeowners, incomparable.
With both hardwood and softwood options out, there it is important to not get too invested in the labels. Catherine Hadwick from Bereco explains: “Contrary to the names, not all softwood is soft and not all hardwood is hard”.
Popular amongst those wanting timber on a limited budget. The wood can be stained but is usually painted. Douglas fir is a very stable, durable softwood while European Redwood (also known as Scots Pine) is less prone to dimensional change and movement.
- Pros: Looks good on both contemporary and period-style homes, and is the cheapest option if glazed and decorated on site.
- Cons: 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.
- Cost: £6,000-£15,000, less if ‘DIYed’ on site.
Hardwoods are slower growing and have a tighter grain than softwoods, making them more stable and durable. The wood can be treated to be further stabilised. Oak is the most popular and is often used on traditional-style homes. It is usually stained.
- Pros: It promises a longer lifespan than softwood and its natural looks are perfect for period-style homes and barn conversions.
- Cons: It’s expensive — anything up to four times the cost of softwood.
- Cost: Between £8,000 and £20,000.
Usually consists of timber windows with a weather-proof capping, such as aluminium strips. Widely used in harsh climates (such as Canada and Sweden), composites are now gaining in popularity in the UK, especially as a triple-glazed solution. They work best with modern designs.
- Pros: Low-maintenance outside, they can offer the look of timber internally.
- Cons: Expensive, and if ordered from the Continent windows are unlikely to be made to standard UK sizes.
- Cost: Between £10,000 and £25,000 — expect to pay 25% more for triple glazing.
The main metals used are steel, seen on some period properties (such as Art Deco), and aluminium, which has in the past been only popular among contemporary-style homes, but increasingly the metal is being used in period properties as people realise the potential to create period looks, typically with the current trend for Belgian doors. GRP (fibreglass) can create a strong load-bearing frame and, like aluminium, can be supplied in any colour.
- Pros: All are very low-maintenance and tend to look better than PVCu and can produce finer frames.
- Cons: Metal is not as thermally efficient as wood.
- Cost: 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.
Once only popular in low-energy homes, triple glazing is rapidly becoming a standard solution for today’s window suppliers. Famed for increased thermal comfort inside the house as triple glazing evens out the temperature profile of rooms, a less well known benefit is improvement in acoustic performance.
- Quadruple glazing (four panes of glazing) is now available in the UK (through Enviro), and can achieve the same performance as standard insulated cavity walls with U values of 0.3-0.4.
- Laminated glass options with an internal resin layer means that windows will simply shatter like a car windscreen.
- Solar Powered glass (Polysolar) is beginning to become a mainstream, albeit expensive, option for homeowners. Although it is not yet offered by suppliers to the self-build and renovation market, this is expected to change in the coming years.
How to Compare the Costs of Windows
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.
The square metre rates are derived from taking the total amount quoted to supply windows and dividing this by the area of the window openings.
The cheapest way of supplying and fitting windows to a new house is to use white PVCu windows, designed to slip into industry-standard window openings. Although you can buy softwood frames for less, by the time you have glazed and painted or stained them, they end up being considerably more than the cheapest PVCu options.
However, note that PVCu windows themselves can vary enormously in price, depending on quality, style and colour — the wood grain effects are around 50% more expensive than white.
Though they can look very good in the right setting, a lot of people really dislike the idea of plastic windows and insist on timber; in fact, sales of timber windows have recently begun to rise again after many years of losing out to plastic.
What often turns people off timber is the requirement for regular maintenance: most timber requires repainting or staining every five years. If you want maintenance-free timber windows, you have to switch to one of the composite systems, which tend to be timber based but have aluminium external claddings.
5 Questions to Ask a Window Supplier
- Where is the material from?
Ensure timber is responsibly sourced and find out if aluminium is consistently sourced or made from various elements.
- How thin is the sightline and do the external frames overlap?
Some suppliers such as Origin can produce frames as thin as 65mm and even lower for fixed units and other suppliers can offer a flush finish for a smarter external appearance.
- What are the tactile elements like?
A nice window can be let down if the touchable elements, such as handles or even the trickle vents, feel cheap and plastic-y.
- What warranties and services are offered?
Many offer good standard warranties that are significantly extended if the windows are fitted by the company’s approved installers.
- What are the frame basics?
Be sure to find out if the frame has a thermal break which means the frame doesn’t directly transition between inside and out without an air gap.