Pane management: How to get your choice of windows right
The pros and cons of steel, aluminium, timber, UPVC and Alu-Clad frames
Windows are also one of the largest outlays of any home improvement project, and prices vary a lot depending on what you choose. Photograph: iStock
Selecting the right windows for a home is one of the biggest decisions to be made when carrying out a renovation or extension. Not only do windows play a big part aesthetically, but upgrading them will also greatly improve the energy efficiency of a home.
Windows are also one of the largest outlays of any home improvement project, and prices vary a lot depending on what you choose. Making the right decision can be an overwhelming task given all the styles, materials, colours and features available. These are some of the main options out there and the pros and cons of selecting each type.
Steel windows have become popular recently because of their industrial look, which sits well with current interior trends. They work internally and externally and look great in a contemporary or period setting.
Compared with timber, aluminium or plastic, steel is by far the strongest framing material and thus can do its job with much finer sections. Steel windows are now available double-glazed and are much better thermally than they have been historically.
But they are also an extremely costly option, so you will need to manage your budget carefully if these are your preferred choice. They aren’t as thermally efficient as other types of windows, meaning you will get more heat loss with this kind of glazing system than you would with other material choices.
A great alternative to steel is aluminium windows. Many of the more high-tech aluminium options available combine great thermal qualities, low maintenance and a very smart appearance, as well as being generally much cheaper than steel systems.
Aluminium offers very slender frames and large sizes of glazing panels, which are suited to more contemporary designs such as floor-to-ceiling sliding doors. They also perform very well thermally, making them really energy efficient.
While aluminium is not as strong as steel, and therefore needs thicker framing sections, aluminium windows offer many benefits. There are sliding systems, top-, side- and bottom-hinged windows, and bifolding options to choose from, so they can be very versatile.
They are also on the upper end of the price range. The slimmer the aluminium frame, the more expensive the windows will be. So again it’s worth budgeting carefully if this is the look you wish to go with.
UPVC is the most cost-effective option but just because it is a less expensive material doesn’t mean it is an inferior choice. UPVC is not an insulating material, but the better-quality windows will have insulation built into the frame.
A well-constructed, properly installed UPVC window can be a practical choice budget-wise, while still offering excellent energy efficiency measures through insulated glass and tight construction that reduces air leakage.
The downside is that UPVC windows tend to have limited colour and style choices and their frames can be wider than the other window options. However, some of the more expensive varieties do come in a wide range of colours and with more slender frames, making them a great alternative to timber if that’s the look that you prefer.
Timber is a wonderful and versatile material for making window frames. They can be custom-made to any style, making them a great choice for both contemporary and period homes.
They also have a natural insulating ability and they can be painted in any colour, making them a popular choice.
Off-the-shelf styles will be more cost effective than a bespoke style. Typically, these windows are less expensive than Alu-clad or metal windows, but more expensive than UPVC so a good option for those working with a more restricted budget. The only issue to bear in mind with timber windows is that they will require maintenance over time.
Alu-clad is probably the most attractive option for many people embarking on a refurb. These are “composite” windows that combine aluminium on the outside with timber on the inside.
They offer the same low-maintenance qualities as UPVC while maintaining a more tactile timber interior, and they also offer great thermal qualities.
They are more expensive than timber windows and do have height and width restrictions for larger glazing, such as floor to ceiling sliding doors, for example.
They are similar in cost to aluminium, but because of the internal timber finish you won’t be able to achieve a slimline frame.
Denise O’Connor is an architect and design consultant @optimisedesign