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Future façades: sustainable design & performance with the adoption of computer-aided technology

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Façades are without a doubt the most important building element from the perspective of both users and architects. In fact, they are the most difficult to design as well, because their responsiveness is based on variables that are difficult to predict and generate in each design that includes social aspects, geography, climatology, and, of course, sustainability, and material costs, etc.

During the past few years, an incredible number of creative building and façade materials have been developed and introduced. Most of these advances guarantee huge upgrades in energy productivity and occupants’ comfort, with easy availability in the market.

What are the current trends indicating the likely direction of the façade in the coming decades? What do industry experts think about future façades, the preferred materials, the technologies, and materials that can be seen in coming years? Read it here in this cover story.

Important Tools for Creating Future Façades

Agnes Koltay, CEO, Koltay Façades, says, everyone is more and more reliant on computer technology, in all areas of our life. Of course, there has been steep accelerating progress of tools assisting our work in façade design and engineering. The first generation of computer-aided design software was aimed to take over the manual labor of drafting, multiplying, and sharing design information. The second generation I would say were task-specific software, to analyze daylight, thermal performance, or use finite element analysis for structural models. The current generation of computer tools are highly customizable, programmable, and connect with each other well. Collaboration tools and cloud computing gained popularity that also helps our work as façade consultancy necessitates a lot of coordination with multiple disciplines.

The information created by the design team gives set out input, quantities, and spatial clarity to the contractors. Manufacturers these days are utilizing computer instructed manufacturing procedures.

She adds, the last step, where the digital revolution has just started, is site organization. Ideally, the elements are coded and identifiable, the installation logistics could be very straightforward even for complex designs, and site wastage or incorrect placement of an element can be reduced to near zero by following the computer dictated sequence. VR (virtual reality) applications – which already infiltrated the real estate sales market- help with a quick check of the match between the intended design and site conditions, provide instant access to required design or procurement documentation, or can document a needed design deviation to deal with an existing site condition.

According to Ahmed El Banawy, Senior Manager – Design, Nakheel, the most important tool is to understand the current market as the market is moving from a product-based business model to a service-driven business model. Embracing the service business model is the most determinant factor for the future development of adaptive façade technologies. He says the future trends of adaptive façades are concentrated around four structural trends namely:

• Human-centred design
• Smart building operating systems
• Service-driven solutions
• Circularity and materials

Alan George, Founder, Orange Design Group believes that the most important tool is knowledge of the built environment. Software & analysis are secondary tools. The fundamental approach has to be sensitive to the natural environment & ideally be able to evolve with time.

Future Opportunities for Smart Façades, Adaptive Façades & Integrated Façades

Firoz Kachwala, Director, Future Architectural Glass, LLC elaborates, all these classifications are interrelated. Technology is surrounding our everyday lives and its penetration into façades is inevitable. Various concepts are already underway to bring innovations in façades to make them smarter, adaptive, and integrated with the built environment.

Dynamic shading elements are implemented in projects wherein the shades track the movement of the sun to get the best lighting while controlling the glare & solar heat gain. These shading elements could be used mechanically controlled louvers that tilt in the right direction for glare control.

Dynamic tinting glass is also gaining traction as a building element. This is a game-changer and is the latest available technology that can tint the glass based on the sunlight intensity thus providing a dynamically changing Shading coefficient on the glass. For an architect, this is the best solution without compromising the aesthetics of the façades. They can get rid of the blinds that distort the façade appearance due to the non-homogenous nature of its use in the building.

He adds, with the advent of IOTs, smart façade products have also entered the architectural segment that can talk to the building management software and control the AC, lights, and ventilation systems by reading sunlight, temperature, humidity, and CO2 content in the interior spaces.

Agnes says, one of these advanced technologies is dynamic liquid crystal glazing, where the glass can change its visual light transmission and shading coefficient properties (can go darker or clearer) with the use of an electric prompt within a second. This technology increases user comfort, reduces heat loads, and can be sensor-driven.

Robotic cleaning options also progressed a lot in the past decade and instead of dare ideas, they became possible and reasonable choices.

Another extremely innovative and interesting technology is water-filled glazing, where water is circulated to control the thermal transmission of the glazing, and through a heat exchanger can even cool or heat the room or harvest energy.

Four Technologies of Adaptive Façades Having Promising Opportunities for High Market Penetration by 2050

• Dynamic Shading Façades: Dynamic shading is not a new technology; however, it has the widest range of solutions (e.g., shutters, louvers, blinds) and the largest market share among adaptive façade technologies. The market value of advanced solar shading is high in association with the growing overheating risk in buildings and move from heating-dominated to cooling-dominated requirements. Automation and smart readiness are the innovative parts of dynamic solar shading. However, though it is perceived as simple, it is complex to operate.

The business growth potential is high (currently 15 billion euros) and can reach 150 billion euros by 2050; if building energy efficiency continues to drive the demand and if further innovations are adopted, for example, dynamic shading can be developed with night ventilation. These technologies are not internal or external to the building but are directly integrated with the glazing. Their physical properties can change according to the level of voltage and power changing the appearance of the glazing itself, making it more or less transparent.

• Solar Active Façades: Solar active façades include several new radical technologies that involve a wide range of new possibilities. This family includes double-skin façades, green envelopes, and phase change material envelopes. Moreover, this family includes several emerging technologies of adaptive façades that might be promising. Currently, solar active façades do not have a large market penetration. Their performance depends on the physical and/or chemical and/or biological reaction of materials to the sun and temperature changes with minimal electro-mechanical intervention. With the exception of double-skin façades, solar-active façades have limited market penetration. Even double-skin façades are not widely used any longer as they can be associated with excessive heat gain in relation to their design.
• Active Ventilative Façades: AVFs are an emerging family that will have a high potential in the near future. They include not only active ventilated CCFs but also active ventilated envelopes with heat recovery units and automatically operated windows (opening). In addition, to achieving thermal and solar control, they also include active ventilative cooling as a key feature. If the rate and depth of building energy renovations will accelerate and overheating avoidance measures continue to drive the demand, AVFs will have significant competitive growth. In the case of actively ventilated CCF, the aim is to control the airflow inside the cavity, whereas in automated operable windows, the aim is to control the air entering the building.

– Ahmed El Banawy, Senior Manager – Design, Nakheel

Façades like skins, have to become more flexible and adapt to the needs of the occupants and environments. The computative design will allow for a tailored solution unique to each project. In addition, “option-during” becomes highly efficient & dozens of variations can be studied very quickly, says Alan.

Current Advancements in Façade & Cladding Technologies and Materials

Alan notes that the economies of scale are finally taking effect. For e.g., a decade back, BIPV (building-integrated photovoltaics) was not only difficult to obtain? But was exponentially more expensive and inversely proportional to efficiency. However, with the slow but steady adoption of this technology, we now have cheaper and more efficient solutions within the global market.

Automation in Façades & Fenestration and its Benefits

Agnes opines, automation in the final stages of design can ensure information, quantities, requirements are consistent within a documentation set and among different disciplines. Automation in manufacturing leads to less wastage, faster and more accurate production. Automation at the site brings efficient logistics, faster progress, and clear and quick access to required information. Automation of the actual façade could be used to control shading, ventilation, access, security, failure reporting, and assist the work of facility management.

Alan says that automation removes the need for human intervention. By definition, the major benefit is efficiency around the clock. But with an adaptive, learning, AI algorithm? The potential for efficiencies is a lot more.

Interactive Façades – Their Benefits and Limitations

Kachwala explains that interactive façades incorporate glass that has the capability to run interactive media on it. It has the capability to transform your building into an iconic landmark, amaze people with inspiring visuals and engage them with interactive content such as games. The feedback loop can be created with the audience and through instantaneously customizable content, glass façades can be used for storytelling canvases. One can create social hubs where people can meet and form a seamless connection between physical and digital experiences.

The Interactive façade, also known as dynamic façade and responsive façade, is a building exterior that can change in response to its surrounding environment to maximize its performance. In this way, the ‘skin’ of the building is not static, but dynamic and can transform according to requirements, says Ahmed.

Ahmed adds that macro responsiveness might include adjustable ventilation or moveable solar shading, used to optimize the amount of solar heat gain and visible light that is admitted into a building, or daylight lighting systems that can help to maximize natural daylight.

According to him, the only limitation is that the cost of customized technology is very high compared to conventional façade.

Energy Harvesting Façades and Their Benefits

Agnes presumes that the energy harvested from the surface of a typical building is still not sufficient for a zero energy design, except where the design is specifically driven by the surface requirement, such as Al Sheraa, the new HQ of DEWA, which is under construction now and we provide site supervision. A further problem is efficient storage of the harvested energy, especially in the case of residential buildings, where the energy use peaks at night time. I see a great future for waste to energy plants, solar parks, and especially nuclear power, the cleanest and most efficient energy of all. Buildings should be well functioning for the purpose of sheltering people in a comfortable environment to live, work, entertain, heal, educate, etc. Power plants should be well functioning and reliable in harvesting energy for the purpose of powering the needs of our modern and safe life.

Ahmed classified the energy harvesting façades into two categories:

• Energy harvesting for buildings based on solar energy and thermal materials such as:

o Solar cells in window glass using a bifacial light collection technology (transparent electrode), an effective strategy to increase the production of energy using photovoltaic devices.

o A new smart blind system uses thin-layer photovoltaic cells attached to the blinds to capture energy

• Energy harvesting for buildings based on wind energy such as Wind generators to convert the strain energy stored in the cables of wind-excited units into electrical power. The proposed structures offer portable applications for small spans and are easy to assemble using prefabricated component parts in the case of large spans. He believes that the future of both types is very promising.

Key Characters of a High-Performance Façade

Agnes explains the main performance aspects into follows:

• Structural soundness: withstand windstorm, earthquake without falling, disintegrating, deforming elements, allow for daily occurrences of temperature changes, live load driven slab deflections, other typical base building movements.

• Weather performance: do not allow water leaking into interiors, provide good airtightness with low air permeability limit value

• Daylight performance: allow in daylight where needed, subject to its function

• Solar performance: keep out (or let in, depending on geographical location) solar heat in the infrared wavelength range.

• Thermal performance: protect the interior premises from heat loss or heat gain due to outside ambient temperatures. Store absorbed heat where such is optimal.

• Natural ventilation performance: allow operable openings to let outside air enter and exit the premises, as needed.

• Acoustic performance: provide protection from external noise, depending on the indented function and the actual surroundings.

• Fire performance: do not ignite or propagate fire, contain an accidental fire.

• Impact performance: provide a barrier to people or expected equipment touching or crashing the surface, provide reduced performance at post breakage state.

• Glare performance: protect the surroundings from light and heat reflection that could be visually disturbing or increase the temperature of the direct environment.

• Maintainability: allow for external access for cleaning and maintenance, allow for replacement

• Buildability: provide easy installation process through practical design and increased prefabrication where possible to increase quality and reduce worker’s safety risk on site

• Health: avoid materials that emit or evaporate harmful substances during manufacturing, installation, or long-time use

• Lifetime: provides long term performance with minimal maintenance and no replacement

• Sustainability: where possible, choose options with lesser embodied carbon, lower energy need for production, and better recyclability.

High-performance façades would incorporate glass and glazing products of high energy efficiency. For example, the glass used on such facades would have a minimum U-value of 1.4 or lower. The aluminium systems would need to be with a thermal break in order to reduce the overall system U-value as well, explains Kachwala.

In Ahmed’s opinion, the high performance includes enhanced sun protection and cooling-load control, improved air quality and reduced cooling loads using natural ventilation schemes, reduced operating costs via daylighting-thermal tradeoff s, minimizing lighting, cooling, and heating, and improved indoor environments leading to enhanced occupant health, comfort, and performance.

Alan states that it needs to be well designed and well-executed. On paper, designs can be optimized, but during execution? If high standards are not maintained, the overall cause is lost.

Features You See in the Future Façade

Agnes Koltay presumes, there is a lot of interesting R&D output for new materials, new technologies, or turning elements multipurpose. The construction industry is the most conservative of all sectors, finding teams of developers, architects, and investors who are daring enough to build something that is unique and first of a kind is a difficult task. “We have been in a good position with the enthusiasm towards new ideas in the UAE and our reputation for a capability to deal with the unusual. Hence, we added our name to quite a few milestones of “limit pushing” projects. The Opus brought a new era in demand for freeform glazed building parts. The Museum of The Future with its iconic shape gave a reference to what digital design and fabrication process can achieve, she says.

The Sky Slide on Sky View adds a new thrilling all-glass structure experience to the UAE with international fame. However, these are iconic, one-of-a-kind buildings. She adds, “What I really would like to see in future façades on a larger, standard, affordable scale in past. Preserving, renovating, and repurposing. Appreciation of history, and preservation of buildings that are – or were meaningful for the community”.

Façades should form a bridge between the outside and the inside. It should talk to the environment and exercise necessary adjustments or controls to adapt the interior space, opines Kachwala. “The façade should connect with the inhabitants inside the building as well as the audience outside and be a medium for meaningful interaction. Sustainability is the buzzword nowadays and with the way global warming is affecting the world it is imperative that we care for the environment and create façades that foster sustainable living spaces”.

Alan says, at the moment, most glazing panels are a clear barrier between inside and outside. However, they could be a lot more. Much more tailored to the individual user. Become more integrated into a daily user’s life. Clear TV displays could be part of the glazing façade? Wireless charging? The options are endless.

Preferred Façade Material

Agnes loves glass. It provides connection and protection at the same time and is unique in this aspect. Being in a room with a view of greenery and/or city life, having the sunshine in, and noticing the slow-moving artistic abstract shadow patterns it casts, brings happiness to all, while still protected from heat, wind, animals, sand, etc. Even watching a storm from the protection of a room, with heavy rain, thunders, and lightning bolts, how cool is that. She says, “I also love the art glass can do: stained glass, enamel art, casting, fusing, and glass blowing. I went to a glass blowing workshop visit in at least 10-12 countries, it never bores me to watch. It’s on me “before I die” list to learn and practice glass blowing”.

Kachwala believes that dynamic tinting glass is the biggest revolution that is waiting to engulf the façade market. This material addresses all the aesthetic and functional requirements of an architect and perfectly adapts to any green building regulation governing the region. It is an ideal material that can provide maximum comfort with natural daylight and optimum room temperatures throughout the day. Solutions are available to automate the façade that would track the outside environment and adapt the interior space to suit the ideal requirements of a human being – and all this can be done seamlessly while one carries on with the activities.

“A bit of a controversial answer, but I must say natural stone. As a truly ‘natural’ material, I have found it has many benefits along the lines of thermal mass & variety? But also aesthetically, stands out in a world of concrete & glass”, says Alan.

Conclusion

To meet the needs of the world as a whole, as well as individual owners, and to meet government requirements, future façades will need to prioritize sustainability. To meet the challenge, technology is playing a critical role in driving clever and sophisticated solutions, transforming the façade into much more than just the pretty face of the building design.

The façade design is an area with a lot of room for growth, and there are so many new technologies that can be used to enhance and make façades both beautiful while also adding value and function to the building as a whole.