The Future of Window Design
9 October 2014
If there is a single factor that can make a self build project stand out as something extraordinary, it is the windows. These elements are critical to the overall design and have the ability to make a building look balanced, or otherwise.
Here, Chris Coxon, Head of Marketing at Eurocell, looks at the factors to consider when choosing windows.
“Most self builders will freely admit that specifying windows was one of the most challenging elements of their project. The problem is that they can soon look out of place, either because they are incorrectly sized, have bulky sight lines or do not perform well enough in situ. We’ve compiled a list of some of the factors worth considering to avoid the pitfalls:
Cost versus Energy Efficiency
For most self builders, energy efficiency isn’t just a consideration, it is the most important requirement. With increases in cavity widths, up to 300mm in some cases, combined with additional insulation, the attention has shifted to windows to deliver improvements in performance.
When you consider that most window systems in the UK were designed over 10 years ago, it just shows how pressing was the need for innovation. The situation is only going to get worse. The latest updates to Part L require on average a 6% reduction in residential and 9% reduction in non-residential carbon emissions from buildings, which will result in a greater need for higher Window Energy Ratings (WER). And future updates will be even more demanding.
The fact that until we unveiled Modus all window profile systems were designed over a decade ago, which means that they pre-date energy performance standards (in 2002 Part L required a window U-value of only 2.0W/m_K or a WER band E). Why, when most people choose ‘A’ rated white goods, would self builders want to install windows originally designed to meet band E or worse?
It was for this reason that we designed Modus with a 75mm super-thermally efficient multi-chamber profile capable of delivering a U-value as low as 0.7 with a standard argon gas-filled triple glazed unit, without the need for expensive, esoteric-specification glazing units. It is capable of accepting double and triple glazed units, to give self builder more choice.
Achieving a U-value of 0.7w/m_K means that it meets zero-carbon requirements. In fact, an ‘A’ rated window with an Energy Index of 0 or above loses no energy and could actually allow solar energy into the house therefore achieving further savings.
Scale and proportion
Getting scale and proportion right is essential when it comes to choosing windows. The most pleasing proportion is 1 to 1.618, the Golden ratio. That means if a window is 1m wide it should follow that it is 1.618m high.
Proportion of the window in relation to the shape of your property should also be considered. A tall, narrow building looks better with tall, narrow windows, whilst a building that has a square front elevation should have windows that are more square.
Following these two important rules will create a harmonious relationship between proportion of window openings and facade. However, even then there is potential for getting it wrong as windows can be let down by poor detailing. So if you’re looking to replicate a period style then make sure things such as the beads, glazing bars, and sashes are all carefully chosen. We designed Modus around these factors, which means that its classical architectural proportions are distinctly different to the angled chamfered and sculpted ovolo systems that make up the market.
Material and sustainability
Getting window design right used to mean that self builders were restricted to one particular material. Timber for traditional style properties, aluminium for a modern aesthetic. However, the very latest window systems, such as Modus, offer more choice than ever by allowing self builders to choose a fully flush sash for traditional aesthetics, slim sash for a contemporary look and a standard sash for improved aesthetics to rival PVC-U systems – all from one single system.
Environmental sustainability was another key factor. We take post-consumer recycled PVC-U from refurbishment projects around the UK and return them to our recycling facility in Derbyshire, which is capable of recycling up to 12,000 end-of-life frames per week. From here the frames are recycled to make new energy efficient window products at our main manufacturing site, which is located within fifteen miles. That means Modus typically utilises 50% post-consumer recycled PVC-U* as standard, although we also offer a 100% post-consumer option. It has a 12-year frame guarantee, compared to ten as the industry standard, demonstrating the confidence we have in our post-consumer recycling processes.
The £3m investment we’ve made in developing Modus, the UK first fully integrated window and door system, has the potential to change the windows and doors sector. It helps that it has no fewer than five industry firsts and has already been shortlisted for the national Housebuilder product awards.
Windows are an intrinsic part of our built environment and that is why it is so important to get them right on all projects. Whether you are building a minimalistic cube with windows punched into the facade or a classically styled Georgian revival the principals remain the same. Modus will help you get these right, whatever your application.”