Architect Christopher Sykes looks at how the ‘rediscovery’ of daylighting is radically changing architecture and is having an increasing influence on our lives. He also examines the new design and engineering solutions delivered by leading glazing engineers and contractors, such as Structura UK .
The historic English window tax was based on the number of windows. It was a significant social, cultural and architectural force during the 18th and 19th centuries and many domestic windows were bricked-up to avoid paying it. Jump to the mid-20th century and designers suddenly ‘discovered’ windows again and took glass in a totally opposite direction. Jump further and many buildings today, domestic to skyscraper, are virtually like fully glazed greenhouses.
Glass is one of the most interesting of building products and is closely connected with man’s cultural and physical development. It now shapes architecture, giving designers almost a fourth dimension involving interplay design between living space and natural space.
The composition of glass equally offers architects the widest aesthetic and physical benefits. Whether the glass be transparent or translucent, coloured or clear, it also needs to juxtapose perfectly with those other materials which it needs for support and which will create a successful fusion and interaction between design, technology, construction and performance.
Performance in practice
Daylighting through the creative use of wall or roof glazing, radically changes building envelope design and the ambience of interiors. It positively influences people, affects how they behave in their environment, changes their circadian rhythm and improves their well-being. For example, retailers sell more when customers experience natural daylight when they shop.
Schools include some of the best examples where daylight is proved to have had an extraordinary effect on behaviour, showing a marked calming influence on pupil behaviour and learning. Statistics come from the US where it was proved that learning rates were 20 per cent higher in reading and 20 per cent higher in maths in classrooms with the most natural daylight, while comparison between students with and without skylights showed 19-20 per cent faster improvement.
There are several interesting new directions which not only are changing our personal perceptions but are fundamentally changing the design and performance of buildings. A good example is the new offices for Blackpool Council designed by AHR architects. Here we see a trend where the facade itself encourages interactive entertainment. It’s not just the clever use of glass but what’s behind the glass which attracts. The meeting rooms are purposely located close to the perimeter so that activity within actually animates the facade. Obviously, this necessitates the clever use and positioning of the windows. This is achieved by a combination of clear full height panes mixed with what is known as fritted glass. This is a simple vertical linear design which reduces the amount of light in some spaces and provides a degree of privacy where necessary.
From Blackpool to Italy for yet another reminder about how the introduction of photovoltaic modules into the glass facade is integral to our energy strategy. One of the highlights of the 9th Energy Forum in October 2014 was the presentation by the Swiss about white photovoltaic modules for facades. With this technology, the highest energy levels are achieved through a combination of crystalline high- performance solar cells with film treated using nanotechnology. This only filters a particular wavelength of light through the cell and reflects the visible spectrum as diffused illumination. In other words, the glass facade is no longer just a daylight introducer, it’s also a fundamental, source of both power generation and solar shading.
While we know that the translucence of glass can be changed from milky opaque to clear at the flick of a switch, we are increasingly aware of digital printing on glass, facilitating branding and integral decoration which again affects the perceptions of observers in the street.
It is similar nanotechnology which gave rise to the remark- able increase in glass insulation performance – essential when architects have to tussle with the twin conflicts of maximizing daylight while saving energy. This has been achieved with materials such as low-E coated glass or aerogel, the world’s light- est and best insulating solid.
Lighting the future
Of course, extreme daylighting is not all plain sailing. There have been a number of high-profile cases where the glazing has not been properly installed or where curtain-walling or atrium roofs have not been regularly maintained.
There also exist plenty of aged buildings which urgently need repair and upgrading, especially where old curtain-walls and roof lights have failed and leak air. Solving these problems and converting older buildings into contemporary showpieces can actually turn disadvantage into benefits, with improvements in both glazing performance and aesthetics.
The innovation of new technology for daylighting new buildings as well as old ones is proving to be a valuable learning process which will influence our use of glass and translucent materials for years to come.