Façade NXT – an Initiative for the Sustainable Future

Building-integrated photovoltaics capture the solar radiation and turn it into energy

impact on the capital cost of Electrical and Mechanical systems and the building’s subsequent operational cost.

In addition to economical aspects, building façades have both positive and negative effects on work performance as well. Negative effects are associated with discomforts, distractions or health risks that interfere with peoples’ ability to do their work whereas positive impacts are associated with enhancing work performance, psychosocial well-being, and health to enhance overall performance.

FAÇADE IMPLICATIONS ON OCCUPANT HEALTH & PERFORMANCE

Performance enhancement is more likely to come from a different set of building features and attributes that affect performance. Lighting that produces glare or visual discomfort is more likely to be associated with headaches and eye problems. Glare due to direct solar penetration and the lack of luminous uniformity across the space distorts the perception of good indoor daylighting.

As per a field study of office workers, it is found that workers who had window views of nature felt less frustrated and more patient, and reported more overall life satisfaction and better health than workers who did not have visual access to the outdoors or whose view consisted of built elements only. The positive effects of nature may also extend to the immune system, thereby directly affecting human physical health.

Thereby, one of the perennial challenges in designing façades is to achieve an even distribution of diffused daylight across the building section.

USE OF COMPUTER SIMULATIONS FOR FAÇADE OPTIMISATION

To achieve optimised façade design from energy efficiency, cost efficiency and occupant comfort perspective, there are specialised computer simulations conducted viz. Wind CFD Analysis, Solar & Daylight Analysis, Glare & Visual Comfort Analysis, Natural Ventilation Analysis, Parametric Modelling. Whereas, for making cost-based decisions on façade, Life Cycle Cost Analysis is also undertaken to enable owners to make more thoughtful decisions.

These computer simulations conducted at different stages of the projects help optimise the building designs to enhance performance and achieve comfort at the same time. The simulations are aimed to evaluate building designs for identifying potential concerns and providing solutions to ensure appropriate façade design by identifying the most feasible and cost-effective options for the project. The quantified results help owners, architects and engineers to make informed design decisions.

Below are the images which demonstrate the pattern of direct sun ingress into space and subsequent placement of workstations to achieve glare-free daylight in indoor spaces:

Images demonstrating the pattern of direct sun ingress into space

Below is the image of Wind CFD analysis conducted to optimise the window openings within the courtyard of this office building.

Wind CFD analysis conducted to optimise the window openings within the courtyard of the office building

Building performance enhancing façades

FAÇADES OF FUTURE

Catering to the demands of an ever-expanding industry and innovative designers, the future technologies in building façades will provide better efficiency, aesthetics and commercial value to the developments addressing a wider spectrum of issues covering the following:

• Façades Generating Power – Photovoltaic Glass Unit

(PGU) Building-integrated photovoltaic's capture the solar radiation and turn it into energy.

A high level of energy generation (up to 15% efficiency) can be generated through a Photovoltaic

Glass unit (PGU). The advantage of this technology is that it is allowing the usage of the fenestration part

Façades generating power

of the building as PGU’s provides transparency to the human eye up to 70%. • Living Façades: A living façade is a vertical surface incorporating vegetation into its structure or face to facilitate various aesthetic, environmental, social or economic functions and benefits.

While research and studies on the subject are limited, it is thought that living façades could make a significant contribution to sustainability if properly integrated.

Also known as; living walls, vertical greenery systems, vertical gardens and vertical vegetated complex walls, they should not be confused with green walls (the process of allowing climbing plants such as ivy to scale a wall while being rooted in the ground). • Interactive Façades: The interactive façade will have to include systems that correct or moderate the performance of the glass as the outdoor conditions change, also allowing for individual occupant adjustment of the indoor comfort parameters.

In the last few years, technological advancements have gone a step ahead as a result of which technologies like Phase Change

Materials, Motorised external shades, automatically controlled integrated blinds in DGUs, motorised internal blinds are already available. This is a positive indication in this direction and buildings are certainly accepting the same depending on the respective business needs and project budgets.

• Façades Enhancing Indoor

Environment – Growing Fresh

Air: Most developing countries have high pollution levels and as a result, the indoor environment can be even more polluted. Drawing ventilation air through a green façade or a

A wall-mounted, modular three dimensional, green façade system with plants showing seasonal interest

Living walls

greenhouse offers a potential to counter the toxins, VOC's, microbial infections etc. in an air-conditioned building. • Dual Skin Façades: The dual skin façade can be simply defined as a system that consists of an external screen, a ventilated cavity and an internal screen. Solar shading is positioned in the ventilated cavity.

The external and internal screens can be single glass or double glazed units, the depth of the cavity and the type of ventilation depend on environmental conditions, the desired envelope performance and the overall design of the building including environmental systems.

• Hydroponics - Façades

Addressing Food Crises: The idea that fruits and vegetables can grow with water, light and nutrients is the basis of hydroponic: one of the innovative systems of making the building self-sustaining. There have been other numerous advantages of this system as well. A reduction is seen in street-level concentrations up to 40% for NO2 and 60% for particulate matter. They potentially contribute to an increase in biodiversity in urban areas by providing a habitat for birds etc. The most important aspect is their “Rejuvenating effect” on the living creatures around as they contribute to softening of the urban landscape and allowing buildings to seem more 'natural’ and pleasing for the people.

Summer Operations Winter Operations Schematic of differen designs of green and iving walls – a direct living wall façade

CONCLUSION

Energy efficiency + Comfort + Wellness are key concerns in today’s commercial construction industry. How important are energy efficiency gains whilst maintaining occupant comfort and well-being from the building envelope is a topic that is gaining momentum amongst industryleading architects and design firms. To address a few paramount issues in the industry, with everincreasing pressure for the dual objectives of higher performance and improved ROI to stakeholders, innovative trends and forces shaping the future of building skin contains the answer of many unfolded domains.

ASHISH K JAIN,

Partner - AEON Integrated Building Design Consultants LLP

ABOUT THE AUTHOR:

Ashish K Jain has over 18 years of comprehensive work experience in the field of Green buildings, sustainability, BIM, interior design and architecture for projects across different countries. He has been leading sustainability groups in India and the Middle East. As a thought leader in sustainability, he has presented several papers at various international & domestic forums and conducted various lectures on sustainability at premier institutes of India. He has been associated with the forums like CII climate change council, ISHRAE, IGBC Green Mass Rapid Transit Rating System, IGBC Green Homes Rating System, IGBC Net Zero Energy Rating System, etc.

As a Sustainability professional, Ashish has strong professional experience within the field of sustainable building design and has been advising professionals of the building industry in sustainability and energy conservation.

Façade NXT – an Initiative for the Sustainable Future

Creating a sustainable future for our future generation is the real need of today. If we keep consuming the available resources, then nothing will be left for the generation next. Sustainability can be achieved in many ways. In this article, I will be focusing on the building sector, particularly the building façade as an energy harvesting component. As per International Energy Agency statistics, the building sector consumes 42% of electricity. Hence, we need to focus on the measure to minimise electricity consumption and at the same time, we need to focus on alternative sources of energy generation. To achieve a sustainable building, we need to look for new materials and new technologies, which are evolving every day. We need to integrate them into our design. This will lead to better building performance and better aesthetics.

The basic function of a building façade is to protect from harsh weather conditions and to provide a safe internal environment and aesthetics. Presently, façade design is more focused on achieving energy-efficient building, achieving better daylight and reducing the HVAC cooling and heating loads. As we move towards net positive buildings, we need to focus on energygenerating façades without compromising the aesthetics. The