Question: I want to improve my home’s BER rating by replacing my windows. But I’m reading conflicting information about what to do. What’s the difference between double and triple glazing?
Answer: There are several differences between triple and double glazing, the first being the number of panes of glass that make up each window. Triple glazed windows have three panes, while double glazed windows have two.
Between each pane of glass, there is, generally, a gap filled with an insulating gas such as Argon. The gas lets sunlight pass through the window and limits the amount of heat that can escape from the rooms inside.
Because triple glazing has two layers of this gas, the windows give better thermal efficiency than double glazed windows.
Triple glazing can be up to 30pc more thermally efficient than double glazing. The energy savings are much higher, meaning your heating bills will be lower.
Triple glazing would also have a lower U-value rating thus reducing condensation issues and would also fare much better than single glazing relative to noise reduction from outside.
Question: I love the loft-style that steel or Crittall-type windows gives to a space and want to install them in the extension that I’m planning. But are they a good choice? What are the alternatives?
Answer: Steel windows have become popular recently because of their industrial look, which works with interior trends at the moment. But they are 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 through the frames with this kind of glazing system than you would with aluminium or Aluclad windows.
A great alternative to steel is aluminium windows. They have come on dramatically since the 1970s versions and are becoming very popular again. Aluminium offers very slender frames and large 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.
Another choice – pictured here – is timber windows designed to the same style, which are cheaper but equally lovely.
Question: It’s bewildering — what are the differences between the UPVC, timber and Aluclad windows? And which is the best choice in terms of insulation and longevity?
Answer: UPVC (which stands for unplasticised Poly Vinyl Chloride) is the most cost-effective option for windows, 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.
UPVC windows tend to have limited colour and style choices and their frames tend to be wider than the other windows options. However, some of the more expensive varieties of UPVC windows do come in a wide range of colours and with more slender frames, making them a great alternative to timber.
Timber windows have a natural insulating ability, and they can be painted in any colour, making them a popular choice. One of the major issues with timber windows are that they will require maintenance in time.
Aluclad is probably the most attractive option for many people. These are timber windows with an external casing or cladding of aluminium. They offer the same low-maintenance qualities as UPVC while maintaining a more tactile timber finish internally.
Question: I can’t afford to replace all of my windows with triple glazing, is there a way to manage the cost? Is it best to opt for double glazing, or just phase the replacement of triple glazed windows?
Answer: If you have a restricted budget, you could consider installing triple glazing on the northern and eastern elevations where there is little or no solar gain. To reduce the cost, you could install double glazed windows throughout the rest of the house.
Do bear in mind, however, that the additional expense for triple glazing is an upfront cost. While triple glazing used to be much more expensive than double-glazing, the difference in cost between the two types has fallen over recent years. Expect to pay about 15 to 20pc more. Triple glazed windows will offer more significant savings on your heating bills over time so that you should recoup your investment in the long run.
If you’re considering purchasing a new home and require the services of an architect, as mentioned above, you can find a registered architect on riai.ie, the registration body for architects in Ireland.
Denise O’Connor is a registered architect of the Royal Institute of Architects of Ireland and managing director and founder of Optimise Design.
Visit optimise-design.com/ for details and check out @Optimise Design on Instagram for inspirations.
Do you have a design dilemma we can help you with? Email firstname.lastname@example.org. Advice provided is for guidance only and readers are advised to seek professional assistance for any proposed project.