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 on 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.

contemporary house with large format window styles

Across the rear elevation of this CLT extension features an expanse of differently-styled aluminium windows, including sliding doors, a window seat and a small horizontal slot window in the bathroom 

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.

Window Styles for Traditional Homes

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 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.

renovated house with period style windows

This Georgian townhouse was renovated to remain faithful on the exterior, while the interior experiments with contemporary design

Contemporary Designs of Windows

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?

Open-out Casements

casement window style in traditional home

JELD-WEN‘s double glazed timber windows in casement style are particularly suitable for homeowners looking to renovate in a conservation area

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 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

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.

period style sash windows in traditional home exterior

The sliding sash from JELD-WEN allow for a period look with modern energy efficiency

Sponsored by Ventrolla

When it comes to renovating older homes with original features, such as sash windows, it is worth contacting a specialist to see if the windows can be repaired or whether replacement is required. If the windows do need replacing then it is a great opportunity to solve some of the negative effects of older windows, such as draughts and rattles.

Ventrolla sash window repair

If you are looking for a sash window replacement, you will need to choose an option that not only maintains the look and charm of the original window, but that also offers increased energy efficiency and noise control as well as being fully draught proof.

Contact Ventrolla for expert advice on sash window repair or renovation.

What Material Should I Choose?

Plastic Windows


  • Cheapest overall although costs var with quality
  • Low-maintenance


  • Can look cheap
  • Can reduce the value of period homes
  • Not easy to repair
  • Doors can be weak

Cost: £5,000-£15,000 for a one-off house.

grey timber frame windows exterior of timber clad house

Sustainable timber windows from Bereco have U values of up to 0.8W/m²K and can be tailored to suit individual designs

Timber Windows

Softwood Pros:

  • 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

Softwood 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

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.

timber frame sash windows in study

This sliding sash softwood timber frame is from JELD-WEN

Hardwood Pros:

  • 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

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

Composite Windows


  • Best of both worlds as they usually consist of timber windows with a weather-proof capping, such as aluminium strips
  • 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


  • Expensive
  • If ordered from the Continent windows are unlikely to be made to standard UK sizes


Between £10,000 and £25,000 — expect to pay 25% more for triple glazing.

timber aluminium windows in modern kitchen

This timber-aluminium window from Internorm is available in a wide range of colours and timber types, in both opening and fixed glazed window options

Metal/Fibreglass/Alloy Windows


  • 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.

flush french windows in modern kitchen

The aluminium French windows in this modern kitchen are from Origin, priced from £400

Choosing the Right Glazing for the Style of Window

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.

large picture frame window interior of contemporary home

Internorm‘s H310 timber-aluminium windows have excellent thermal insulation values

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.

For replacement windows and new windows for extensions, low-E double glazing is required to satisfy Building Regulations in the UK (such as Part L1B in England).

Low-E double glazing can reduce the heat loss through the glass by as much as four or five times compared with single glazingIn areas of the home susceptible to overheating, such as conservatories or large glazed extensions, solar control glass can also be specified to reduce excessive solar gain in the summer.

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.

How to Compare the Costs of Windows

traditional house with period style windows

The four-bar sash windows of this traditional-style Cotswolds self-build was specified to adhere to certain planning requirements

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.

Ordering Windows

sustainable timber windows in bedroom

Bereco‘s Ambient acoustic windows offer an A-rated certified noice reduction level of up to 42dB

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.


Articles like this Comments
  • Barnaby Dickens

    Two things: 1) If you care about the environment, timber is by far the best solution; and 2) today’s factory-finished engineered softwood windows only need recoating every 8-10 years.

  • Isabel Stone

    This is such a good post for people like me who’ve just moved into new offices! Honestly it’s such a stressful time when you’re trying to sort everything out! My new office base is a really lovely building with beautiful views and big old windows, which is lovely but there are so many problems surrounding it – and one of the biggest ones is literally just all the glare from the sun. Though the office looks really pretty, several of my employees have been complaining that they just can’t see through the glare half the time. We have curtains and things but once we close them – the office looks quite dingy and dark and I think it’s a depressing environment to work in! I really want to sort this out as soon as possible because I really think a nice working environment is crucial in helping office moral! Does anybody have any office hacks for dealing with window glare that they could offer me? I did some research and know that you can purchase a type of ‘anti glare’ sticker type thing to put over windows (this is an example of one of the glare window films things so you know what I’m on about) – but I basically wanted to know what people thought of them? Has anyone else used this type of product before? If so what did people think? Are they good for offices? Or is there another better way to sort out the problem? I’d massively appreciate any help here that anyone could offer me! Thank you!

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