There are a wide range of products and technologies available to achieve high-performance systems.
Façades play multiple roles such as aesthetics, day lighting quality, visual connection, thermal comfort, acoustic performance, and energy related performance. In such a scenario, it is but natural that the materials used and the way façades are created receive much attention in terms of research & development. Over the last few years, this has resulted in a wide range of products and technologies available to create high-performance systems. Kapil Chikodi, business development head, Glass Wall Systems, says, “Several innovative materials have emerged in the market. Some of the new materials that have caught the fancy of architect’s and clients alike are aluminium, steel, high pressure laminates, ceramic tiles, stone cladding and stone cladding jaalis, etc.” Stone façades are tested through a water test done on new materials, besides checking for wind pressure, weathering conditions to see how they react.
Besides this, there are some interesting glass products that are becoming popular. Amit Bhadu, communications & marketing manager, Technal, Sapa BS India, says, “There are interesting glass products available such as PV modules, dichroic glazing, glazing with integrated louvres, intumescent glazing systems, and electro-chromic glass that changes from clear to opaque within a second. Glass Reinforced Concrete (GRC) is new to the Indian market, but slowly making its way. The material and technology is well proven and provides a clean external finish, with an ability to form more complex shapes.”
With advancements in concrete, Ultra-High Performance Concrete (UHPC), which is high strength concrete that can be used for pre-fabricated panels and Light Transmitting Concrete, offers innovative opportunities, he adds.
Some of the other materials that are also popular are perforated sheets, aluminium meshes, expanded metal panels, compound curved ceramic tiles, Corian façade panels, and ‘sci-fi’ materials such as thermo-formed plastic tiles.
Architects and contractors are spoilt for choice. With different kinds of materials, textures, colours and iterations to choose from, one is sure to find something that fits the project at hand. Contractors usually look for properties in materials that are lightweight, durabley, resistant to external forces, conserve energy and the possibility of integrating it to its aluminium joinery systems while deciding on the material.
Navin Keswani, MD, Aluplex India, says, “Traditional materials used as infill panel have been glass, aluminium sheet and ACP (Aluminium Composite Panel). These days with technological innovations, newer materials are being used as infill panels within the façade system. These include: Stone such as granite wherein it is incorporated within the Unitised System; ceramic porcelain materials such as neolith; sound absorbing perforated panels with wooden slats; and curved glass panels with minimum tolerances to achieved complex geometries.”
Rohit R Sharma, director, projects, Innovators Façade System, says, “The study of vertical greening systems and their behaviour in relation to air quality improvement, aesthetics, energy saving, biodiversity, mitigation of the urban heat island effect and its social impact is the one we need to focus upon.” Green façades can be classified into two main categories, namely, plants rooted into the ground and plants that are rooted in artificial substrate at grade with watering system. Its application could be directly to the wall and also indirectly to the wall with a supporting structure such as net system or cable and wire net system.
While vertical greening systems have several advantages, some of the disadvantages are: Chance of damage on façade in case of green façade directly to the wall; maintenance; costs on living wall systems; and irrigation issues.
AP Mahesh, regional director (South Asia), Meinhardt Façade Technology (India), says that clients also want materials, other than composites, that are lightweight, green rated, and offer ventilation. Moreover, a façade should have a lifespan of least 25 years, he adds. While Rajan Govind, director, BES Consultants, says that timber finish, a composite material called high pressure laminate material, is much in demand, not to forget metal finishing cladding material and decorative glass.
AUTOMATION SYSTEM IN FACADES
Driven by technological advancements in transparent building façades and the general motivation for energy efficient buildings, façade design alternatives have shifted to utilising dynamic fenestration and shading systems for optimal control of daylight and solar gains. Bhadu says, “Glare can be controlled if automated shading is used in perimeter zones. Roller shades move automatically so as to block direct sunlight and allow diffused light into the room, and horizontal (venetian) blinds re-direct natural daylight deep into the space and improve lighting uniformity, while automated operable windows allow for natural ventilation.” Dynamic building envelopes include advanced window technologies, innovative fenestration systems and automated shading control, all of which characterise the new “intelligent” buildings generation (together with efficient HVAC control systems). Although a great idea, the design and implementation of such systems is a quite complex task.
Keswani says that automation of façade systems include:*Sunergy Systems: Automated louvre shading systems adjust their orientation depending on the intensity of the sunlight. Aluplex has used this innovation in the Platina building in BKC.
*Automated Smoke Vent Systems: In case of fire, the automated smoke vents installed within the façade allows for immediate opening of the vents.
The design of an efficient façade or fenestration begins by defining Key Performance Indicators (KPI) for the building, depending on its location in India. Design refinement supported by sun path analysis and energy modelling with the selected KPIs further govern choices of material and design.
THE LONG RUN
The workability of the maintenance of the façade is equally important as the construction of the beautiful structure. Having the right tools and access to the periphery of the façade for the daily maintenance keeps the aesthetic as desired during its proposal stage. Definitely there needs to be a break even between the cost at what one has proposed for a project to the cost at which one ends up selling it. Hence in a budget oriented project, it’s always wise to create a symmetry driven façade which would reduce the wastage of our material and hence ultimately reduce our carbon footprint.
Sharma says, “In this period of energy conservation, exploration of kinetic façades and its implementation in an economical fashion is one step in that direction. Integration of these strategies for kinetic façades will increase durability and suitability of the façades with the current building demands, which targets energy efficiency and thermal comfort level.”
Different concepts of science need to be integrated such as energy performance, day-lighting control and aesthetics, which are new to contractors and a challenge that will help them in educating the masses in future.