Whether you’re self-building or renovating, windows shouldn’t be an afterthought. Not just crucial to determining the look and feel of your finished property, they’re integral to ensuring your home is warm and comfortable all year round – it’s something all self-builders need to be thinking about.
Once, glazing was relatively simple – choices were limited. But in just a few decades, technology has come on leaps and bounds. Now, there’s a bewildering array of products and brands out there vying for the self-builder’s attention – so how do you cut through the noise and find the perfect, most energy-saving picks for your property?
Think about the U-value
The best window, door and conservatory products lose as little heat as possible, keep your home warm, your energy bills as low as possible and minimise your environmental impact. Traditionally, in glass and glazing we measure a window’s thermal performance by calculating its U-value – in short, how quickly the product lets heat escape. The lower the number, the better the product’s energy efficiency. Building Regulations require all new windows to achieve U-values of at least 1.6 – and for the best performance, you ideally want windows with 1.0 or less.
Thankfully, recent advances in technology mean there’s now an extensive selection of products capable of delivering that level of outstanding energy efficiency – but to start narrowing them down, the first big choice you have to make is which material you want to use.
Choose the right material
For contemporary-style projects, there’s no substitute for high-quality aluminium. Sleek, stylish, and with slim, elegant lines that maximise the intake of natural light, modern aluminium can add an airy, modern vibe to any project or property.
As a material, aluminium has come a long way in recent years – once known for its poor insulation performance and puddles of condensation, the development of multi-chambered frames and the polyamide thermal break (a plastic section that prevents heat escaping) has made it one of the best all-round materials on the market.
But, what if you’re looking for something more traditional? While it might be surprising for some, one of the best options is actually now uPVC. A lot of homeowners looking to bring a high-end or period aesthetic to their property wouldn’t even consider what was long dismissed as a cheap and nasty material – but most people’s perceptions of uPVC are now several decades out of date. The result of extensive product development, modern uPVC ranks among the best-looking, best-performing materials now available – and the desire to combine all-round exceptional performance with classic looks has seen manufacturers compete to produce uPVC window products that are all-but indistinguishable from timber.
Foremost among these is Residence 9. Designed around the stringent Article 4 guidelines that govern which products can be installed in conservation areas, Residence 9 is a uPVC window system built to the exact dimensions of a 19th century timber sash window, delivering stunningly symmetrical vintage elegance, along with industry-leading 21st century performance. With an A+ certified energy rating, a double-glazed Residence 9 window can achieve U-values of 1.2, and as low as 0.8 with triple-glazing, enough to meet Passivhaus standards.
Don’t neglect the glass
A lot of self-builders spend so long agonising over which design of windows to choose that the glass doesn’t even cross their mind – but it’s a crucial decision to get right if you want to cut costs, reduce your carbon footprint and get the best possible thermal efficiency.
Window technology has come a long way since the development of the first double-glazed units. Now, the most advanced window products have been upgraded to incorporate gases like argon, that have 34% less thermal conductivity than air, and can cut a product’s U-value by as much as 30%. Most window units now incorporate warm-edged spacer bars – components designed to improve a product’s energy efficiency even further.
It’s a shift that’s been complemented by improvements in other areas of the industry – old-style polycarbonate conservatory roofs have been replaced by scratch-resistant, thermally insulating glass ones, which makes modern glazed extensions among the most energy-efficient conservatory options on the market.
You’ll thank yourself for working hard now to maximise your property’s energy efficiency – but, particularly if you’re renovating an existing building, don’t forget about ventilation. New windows can drastically improve airtightness, which is obviously a good thing – but you need some airflow to let out moisture. To combat dampness and mould inside the home, make sure you use windows with trickle vents, which are specially designed to allow a small amount of controlled ventilation and keep damp at bay.
The good news is, while the sheer scale of choice might feel overwhelming, there are more stunning, fantastically efficient, premium-quality glazing products available now than there ever have been – you just have to know what you’re looking for to find them.