Aesthetically Pleasing Efficient Intelligent Building Skins Engineering Essay

Architecture is no longer static and unchangeable – instead it is dynamic, responsive and conversant – The idea that building skins reflect the skins of living organisms: properly designed, they breathe, change form, and adapt to variations in climate – But can highly efficient intelligent skins still be aesthetically pleasing?

“A building becomes a chameleon which adapts. A properly equipped and

responsively clothed building would monitor all internal and external variables,

temperature, hygrometry and light levels, solar radiation etc, to determine the best

energy equation given these conditions and modify the building and it’s internal

systems accordingly. It is not too much to ask of a building to incorporate, in its

fabric and its nervous system, the very basic vestiges of an adaptive capability.”

(Rogers 1978)

The aim of this paper is to explore the notion of incorporating intelligence into a buildings façade. The discussion about the energy efficiency of façades has inspired many architects to no longer view the building envelope as static but as a dynamic being, that can adjust its shape, surface, function and interior spaces in real

time in response to intelligent controls that monitor active feedback from the

environment. Solar and wind energy, daylight, and water can be captured

by buildings and reused efficiently. An Intelligent building is one that combines both

active features and passive design strategies to provide maximum user comfort by

using minimum energy. The intelligent façade forms part of the intelligent building, it

is what protects the inhabited interior whilst controlling exchanges between inside

and outside at the envelope level. The plan being to respond effectively to changing

climate conditions and inhabitant needs in order to improve functional performance. A buildings façade doesn’t just play a key role in the sustainability of a building; adding to both energy efficiency and the quality of the internal climate. It is also a fundamental part of the building’s aesthetic, adding to the structural outline and defining its visual impact on the urban surroundings. A façade can only be described as intelligent when it makes use of natural renewable energy sources such as solar energy, airflows or ground heat to meet a building’s requirements in terms of heating, cooling and lighting. The idea that the fabric of a building can increase its interaction and response to external changes and internal demands with a prime objective of lowering the environmental load is an exciting concept. The facades almost become local, non-polluting energy suppliers to the building.

The notion of intelligent building facades is not a new idea; however the implementation of high-tech skins has been slow. While fashionable and almost certainly advantageous, sceptical architects are afraid that operable components are magnets for value engineering or foresee them being stripped off their buildings in the future due to poor performance or poor maintenance. However, the rising cost of energy, latest environmental initiatives and the focus on the green propaganda has put great responsibility on architects and engineers to make continuous energy savings and this must be achieved through effective building design and clever management. Almost seven years after the European Union passed legislation requiring property owners to report on the energy performance of their buildings, a new round of tougher regulations is under way. Plans to revise the Energy Performance of Buildings Directive (EPBD) in 2010 are expected to result in even tighter emissions targets for new buildings. Gradually more and more architects are beginning to enjoy automating their facades rather than leaving energy-efficient functions to chance. Consequently, the crucial boundary connecting the interior environment and the elements is getting more consideration and consequently more animated.

Most buildings today are equipped with increasingly advanced technologies, but few still seem to be utilizing the true potential that this green intelligence has to offer. The intention of this study is to take the idea of the intelligent skin much further and realize what could potentially be possible in the future.

The paper will go on to describe the context within which the need for variability in building skin performance has arisen and demonstrate how such dynamic response mechanisms have been incorporated into the design and construction of three buildings; The GSW Headquarters in Berlin, by the architects Sauerbruch and Hutton 1999. The Debis Headquarters building, Berlin by The Renzo Piano Building Workshop in 1997 and the B4 and B6 office buildings in Berlin by Richard Rogers 1998. All three case studies are purpose built office buildings that were built around the same time frame and are in the same European climate, Germany. The climate in Berlin is known as ‘continental’. The summers are warmer than the UK and the winters colder. Summer temperatures can rise to 32 degrees centigrade while winter temperatures can drop to -15 degrees centigrade.

After German reunification in 1990 Berlin was to become the gateway to the whole former Soviet Communist Empire as it was transformed into an economic epicentre by new investment from the West. A skyline of construction cranes rose over the city, citizens marvelled at the remarkable commitment to entwining a city separated for 50 years. Berlin bravely tried to reconcile its catastrophic past with a new visualization of the urban future. Potsdamer Platz has been the site of the extensive redevelopment, instigating all three of the buildings in the review. Because of this, the buildings should employ reasonably up to date technology and design, which can be effectively compared and critiqued in the study. Not only this, but through a growing trend, buildings that employ environmentally conscious technologies are still the exception in most of Europe today. However Mary Pepchinski explains why for many reasons Germany appears to be the leader ‘Many German architects and engineers sincerely care about the effect their buildings have on the environment, but others realise that new technologies will be profitable in 10 to 20 years time. Politically, Germany’s powerful Green party also influences national environmental policies.’ (M, Pepchinski 1995:70)

The overall purpose of this review is to determine whether functional and aesthetic value can be effectively combined in a single project while still managing to cut energy consumption. However to establish whether the buildings have aesthetic significance one must first determine the criteria for aesthetic judgement.

Aesthetics examines our response to an object. Judgments of beauty are sensory, emotional and intellectual all at the same time. Viewer interpretations of beauty possess two concepts of value: aesthetics and taste. Aesthetics is the philosophical notion of beauty. Taste is a result of education and awareness of cultural values; therefore taste can be learned. Taste varies depending on class, cultural background, and education. According to Philosopher Immanuel Kant writing in 1790, ‘beauty is objective and universal; thus certain things are beautiful to everyone. The contemporary view of beauty is not based on innate qualities, but rather on cultural specifics and individual interpretations.’ (Kant 1790)

The criteria for assesing whether the buildings are aesthetically pleasing in this study will be based on two or more views, that of architects or journalists and my own personal opinion. Because judging aesthetics depends on individual interpretations, one is hard pressed to determine the answer, however if based on two views, both can be taken into account, and a conclusion come to. To asses whether the building meets the technological efficiency will be based on performance data or statistics and an engineer’s view. By also looking at whether or not post occupancy evaluation (POE) methods have been adopted at the as-built stage, involving the views about the buildings from the perspective of the people who use them. It could give vital information on building user perception assessing ease of use, controls, facilities and most importantly perceived visual appreciation.

GSW Headquarters – Berlin – Sauerbruch & Hutton Architects 1999

This landmark office tower is an exemplary example of sustainable architecture making use of energy-conserving features. It was the world’s first thermally flued tall building. The most important aspect of the low-energy concept is the highly transparent and dynamic high-rise façade. Colourful orange and pink automated shading panels in the west double skin cavity manage solar heat gain and day lighting. These perforated metal shutters give the building its unique and ever varying appearance. They can be both pivoted and moved aside mechanically or individually by the user; therefore the composition of the entire west façade depends on the habits of the occupants. This creates a distinctive ever-changing pattern causing the structure to come alive.

Whilst elegant in simplicity, form and function, the design results from a highly technical discourse in which the engineering and architectural principles rely largely on each other. The design process involved a high level of collaboration between the architects and the engineers-Arup London. The multiple functioning envelope required the main elements of the building to be the result of excellent teamwork. To minimise heat loss both the East and West perimeter walls are designed as double skin facades. The West façade acts as a solar flue, it has three layers; the inner layer consists of a double glazed aluminium curtain wall in which every second bay has an operable window. The vertical posts of this inner façade carry cantilevering brackets to support the outer façade – this layer is single glazed and consists of 3.3m x1.8m laminated glass panels. Airflow within the inner and outer skins of the façade can be regulated according to seasonal and weather conditions by dampers at the top and bottom. Natural ventilation is brought in through the East double skin façade. Fresh air enters the building, passes through the interior spaces, across specially designed corridor openings, and is extracted by the solar flue of the West façade, which offers particularly good thermal insulation. “The East façade with its porous ventilation openings is like a smooth skin, where as the West façade – deep and separated into layers – resembles a fur.” (UME 2001:29). The reduced depth of the tower along with generously sized windows allows maximum day lighting, creating optimum conditions on the office floors making most artificial lighting redundant.

The brief noted the building had to be a low-cost, socially sensitive structure, which addressed the historic urban context and street planning, but still provide a strong image as the headquarters of GSW. It also had to have functional quality in connecting new and old buildings whilst ensuring operational environmental efficiency. ‘The overall aim for the mechanical design was to improve the building’s sustainability rating by achieving energy savings of 30-40% in comparison to an ordinary building.’ (www.arup.com) the structure is integrated in a three-dimensional composition, offering a working environment which is beneficial to team-working and customer-focused operations. In 1999 natural ventilation was reportedly ‘used for 75% of the year and the building hardly saw the need to operate its air-conditioners’. (NSG space modulation) In the Property EU Magazine M. Korteweg said

‘The building is excellent in its passive control of energy consumption, with CO2 savings estimated to be 55% of equivalent air-conditioned buildings.’ (Korteweg, M)

In my opinion the tall, slender 85 metre tall structure that is curved in shape adds an interesting addition to the urban skyline. The bright coloured red, pink and orange shutters on the West façade are undoubtedly what makes this building stand out from the crowd. It looks like a radiant mosaic, very different from the silvery white East façade. I consider colour to be a fantastic medium to address the senses. Colour is used actively in design as a means of generating atmospheric and distinctive buildings, and I think in this structure it works particularly well. It certainly looks the part but this buildings image is not just skin deep, it also plays the part in reducing emissions and saving energy. The fact that these vivid panels are not just decorative but also functional makes the building so much more fascinating. At night the exterior of the building is lit up, making it easily recognisable, even from a distance. Showing how functional and aesthetic value can be united fantastically in a lone project.

In the Architectural Review magazine, James Russell describes the building as

“An array of energy saving strategies and staff amenities in a colourful, stylish package” (Russell, JS 2000:156)

‘Reunification put the site back at the centre of things, and the colourful new sun-shades on the west elevation energise the neighbourhood.’ (Russell, JS 2000:156)

To sum up this sophisticated mix of bold good looks and intelligent features and to evaluate the success and failures, I would say that this building works astonishingly well on both levels. The building lives up to what the brief intended.

The Debis Headquarters – Berlin – The Renzo Piano Building Workshop 1997

The Debis Tower was the first building in the initial stage of the huge Potsdamer Platz development, which was anticipated to give Berlin a new spirit. It is a pioneering energy-conserving design an exceptional example of environmentally progressive architecture celebrating design and technology. It comes across as being subtle and rather understated compared to some of the surrounding urban infrastructure. It has a certain graceful and distinguished modesty. The East facade of the tower is dominated by biscuit coloured terracotta cladding, horizontal and vertical terracotta slats create an accurately proportioned pattern, which expresses every floor and bay within an overall texture resembling a sort of skeletal skin.

The building is technologically sophisticated; it has a highly effective curtain wall, which offers considerable advantages in terms of the preservation of energy, day lighting, user control and comfort. The interior skin consists of a visually delicate and subtle glass-breathing wall. It features double-pane operable windows, allow the individual inhabitants of the offices to adjust their own internal climates all year round by taking tempered air from the 700mm wide cavity for natural ventilation. The exterior façade is made up of 12-mm thick, automated, pivoting, laminated glass louvers. The smallest amount of air exchange takes place through these louvers when closed. Allegedly the thermal devices designed for the façade work so well that ‘natural ventilation is used for around 60% of the year’ an exceptional percentage for a building in a northern climate. In addition, ‘there is a 50% reduction in the energy consumption of the building and 70% reduction in the emission of carbon dioxide’. (NSG, Space Modulation).

Energy conservation was a significant aspect of the design policy for the building and the project was awarded funding from the European Union Joule II research programme to help finance the design of the facades.

To create this environmentally sustainable building many factors had to be considered and contribute towards the design. One being water management. The building makes proficient use of the rainwater it collects, some of the rainwater is used to irrigate the surrounding landscape and vegetation of the building, some is used as water for toilets, and the excess is used to fill the nearby pond when the level drops. The building is accounted to ‘save around 20,000 cubic metres of water a year’. (Arch Review 1998)

This building is very different from the first case study I looked at. It doesn’t make a huge statement, clad in bright, bold colours and doesn’t stand out significantly from its neighbours. I think it is delicate and rather subtle in the way it looks. A continuous rhythm of horizontal terracotta louvers interrupted by ever changing individually operable blinds, creating an interesting pattern.

In the Architectural Record J.Russell gave his opinion of the building ‘At some times of the day, the sun sparkles from the bevelled bottom edge of the pivoting glass panels; at others, it picks out elements between the glass walls: the vertical glass returns, the metal façade-support structure, or the maintenance platforms. The terra-cotta elements don’t move, but their raw-claw finish invites touch. The rhythms of open and closed cladding along with deepening and lightening shadows as the light changes through the day have their own sensuous appeal.’ (Russell 1998:135)

To begin the process of discussing the successes and failures of the building, I am struggling to find a part of the building’s environmental aspects that can be described as a failure. Even tiny details seem to add to the sustainability of the design. The energy-saving approach of the facades combining terracotta and glass screens gives the building a visually rich texture and a highly practical purpose. The building has an innovative environmental approach and careful design detailing, making it an all round success.

B4 & B6 office buildings – Berlin – Richard Rogers 1998

Like the previous case study, these two office buildings were part of the much bigger master plan to redevelop the devastated Potsdamer Platz area of Berlin. In this dense urban context the aim was to produce innovative environments for businesses, which must be strikingly contemporary in appearance, and most significantly, utilized a low-energy servicing agenda with a high-quality user comfort. The façades are made up of identical modules of which their basic identical construction can be varied by using different in-fills according to the orientation and performance requirement. This allows different parts of the building to perform in different ways, depending on its specific position. The materials used are clear and opaque glass panels, ceramic tile cladding, and external and internal blinds, a sophisticated mix, which allows the internal environments to be adjusted in response to the requirements of the occupants.

The hollow core plan form of the office buildings is cut away gradually from roof level down flooding the atriums with natural light. The atriums are entirely naturally ventilated. In order to optimise the thermal conditions and airflow in the atrium computer simulations were conducted. Solar radiation contributes to the heating and thereby reduces energy consumption in the winter. The natural ventilation ensures that a comfortable climate prevails in the entrance area and the offices adjacent to the atrium throughout the year. A great deal of daylight enters the offices through glazing; this solar radiation is used to heat the fresh air from outside and naturally ventilates the offices. It was estimated that energy consumption in the office buildings would be 50% less than that generated by a conventionally air-conditioned building.

When visiting this building what initially stood out to me was how much more high-tech it looked than the previous two case studies I had visited. The energy saving devices seem to stand out more and are what primarily make up the interesting, dynamic façade. The building is made up of two blocks, symmetrical from the front. Similar to the GSW headquarters, brightly coloured solar shading blinds are used. In this case they are bright yellow, and feature at each end of the building almost acting as bookends. In terms of aesthetics, I think the building is visually interesting and fits in well with its surroundings. Kenneth Powell described the completed buildings as “Striking expressions of the rise of an eco-architecture on a grand urban scale.”

(Kenneth Powell)

The amalgamation of environmental technology and design in these three case studies seems to have created visually attractive and interesting facades that credit the surrounding city. However it has been argued that ‘Design of such environmental screens has concentrated on technical developments with little appreciation that facades are the public face of architecture.’ (Moloney, J. 2007:461) this is a strong argument, which I cannot disagree with without taking every case into account. In the past environmentally aware buildings have sometimes been perceived as inept and unattractive. But times have changed. Technology and aesthetics should be able to run alongside each other in harmony. Architects are now beginning to use energy saving strategies to their advantage to create more unique, interesting facades. Solar shading devices can add a huge amount of visual interest to a building, creating an ever changing dynamic pattern, just like the buildings featured in this review.

Climate change is undeniable. Therefore the demand for more efficient, next-generation adaptive systems for building facades is increasing. What has the future got in store for adaptive facades? New innovations in façade design are primarily down to advanced technical developments in both computer technology and materials. The building envelope is a critical area of a building’s design, with the facade engineer playing a vital role in bringing the architect’s vision to life. New cladding materials and processing techniques are continually being developed in the search for better façade performance, making the design and procurement of the building envelope a highly technical and complex process – yet one that is still immensely creative.

Various architects have presented performance-based prototypes as technological, social, and utopian solutions for the problems we face. Here are two examples:

 

Adaptive fa̤ade РFluidic muscle technology РProf Ir Kas Oosterhuis 2003

This was a competition, its aim being to come up with an innovative idea to create a façade that has flexibility that will enable the occupants to have total control of the light levels in their immediate area, rather than have a centralised controller. Currently most solar shading devices have no facility for localised control and the whole façade has to change at once and can usually only be set to fully open or fully closed. This system allows the building users in any part of the building to set their own preferred light levels. The muscles are made of silicon coated polyamide rubber with steel valves at each end, the shades are inflatable cushions made of polyester coated with hypalon and the whole assembly is joined by steel fixings. The structure is very lightweight meaning easy attachment to existing buildings with little disruption. It can therefore be used to enhance the aesthetics of a mundane building. The facade brings attention to the building by the way it moves, it makes the building appear as if it’s alive, as the skin pulsates and opens.

“Edge monkeys” (theoretical idea) – Stephen A. Gage and Will Thorne (British architect-academics)

In an article published in the cyber journal ‘Technoetic Arts’ Stephen A. Gage and Will Thorne describe a hypothetical fleet of small robots they call “edge monkeys.” Their function would be to patrol building facades, regulating energy usage and indoor conditions. Basic duties include closing unattended windows, checking thermostats, and adjusting blinds. But the machines would also gesture meaningfully to internal occupants when building users are clearly wasting energy. This sci-fi sounding scheme crystallizes the widespread concern informing many recent architectural projects.

Today, activating a buildings skin is in fashion. From the “robotecture” labs at top architecture schools to interactive art installations. Aesthetics and technology are converging in unlikely places. Nonetheless, the mainstream drivers for interactive envelopes are sustainability and strict energy codes.

Conclusion-

At the conclusion of this review, I have gained an appreciation and better understanding of this new trend towards intelligent façades. Although it is somewhat difficult to conclude this study, primarily because the outcome really depends on individual interpretations and taste. By comparing the views and opinions of more than one person, I feel an honest result has been achieved. Yet due to the lack of commonly accepted methods and relevant supporting data for technology, the assessment of the overall performance of the intelligent facades cannot be carried out. It remains difficult, if not impossible, to carry out a fair comparison between different case studies in terms of intelligence. The different examples show that there isn’t only one intelligent façade system but rather that depending on the case in order it is an individual solution according to the location and utilization of the building. As a result it proves difficult to compare the case studies in this report. However looking at them individually the environmental data and statistics collected all point to succesfull levels achieved. The facades seem to be doing their job by reacting intelligently to the climate and impoving internal conditions while still cutting energy consumption. The conclusion reached is that with the combination of these three elements: new technology, innovative materials and very good design, highly efficient intelligent skins can still be aesthetically pleasing. But do technically innovative buildings always come in such stylish packages?

What twenty years ago was perceived as clumsy and unattractive eco-buildings and deterred architects from a design perspective is today an aesthetically interesting and multi faceted solution. In the design of new buildings, the sustainability aspect is particularly popular – and the façade returns to its initial purpose of representation: bold, transparent and sustainable architecture is implemented with minimal conflict as a general rule. Another thought is that intelligent facades are possibly perceived as being visually attractive because of their environmental advantages in a world where being ‘green’ is in vogue. Or more philosophically, people are attracted to facades with moving parts because motion seems to herald change.

Michael Fox an architect and robotics expert predicted ‘Architectural environments will be increasingly smart and responsive and capable of complex behaviours.’ But one must question whether such promises have been realized? And what is needed to push the idea forward and turn the promise of extraordinarily intelligent façades into a reality? Steps need to be taken to develop these products quickly. We are in the midst of global climate change, the way we think is changing and the way in which buildings are designed and made must also change. Adaptive, intelligent environmental strategies offer a critical contribution to the broad ambition of reversing environmental damage.

Intelligent facades will, one day in the near future become a necessity/commonplace and that in time may hinder the obvious aesthetic merit of exemplar buildings like the ones shown in this report.