Building for health
A good façade and fenestration can act as a steward of outdoor pedestrian welfare and contribute to the well-being of residents or inhabitants.
BY Jayashree Kini Mendes
They are undeniably complex systems to create, but they are part of the building that is visible to the world, sometimes even from afar. The façade is the perfect canvas for the vision of the developer, the creativity of the architect and innovation of the engineer/fabricator. While the first two are conceptual, it is the engineering that is much broader and encompasses everything from the performance of the building enclosure systems, which involves below-grade assemblies, curtain wall and skylights, the precast concrete, stone, or masonry walls, to the heavy timber or any other variety of façade systems and materials being used. Little wonder, why excellent engineering is what makes or breaks a façade.
Speaking about the innovations in façade in the recent past, Niraj Borikar, head marketing, FunderMax India, says, “There has been much excitement in terms of innovations. We alone executed a number of projects using unique and innovative applications like horizontal and vertical louvers as sunscreen façades, perforated applications, curved façades, projects with colourful façades, etc. across the country. Sun shading façade is in vogue as it helps in optimising the light entering the building while reducing heat ingress and allowing for ventilation. When it comes to colours, we see a willingness for glamourous colours to make the façade colourful and attractive.”
FunderMax strives to improve specifications to add value to every square metre of façade. This has paved way for offering a complete system with MAX Exterior panels assuring high quality of accessories for substructure through enhanced specifications. It offers flame retardant MAX Exterior panels of Class B, and has recently launched a new façade panel “m.look” which has fire classification of class A2 and are offers higher safety without compromising on the design freedom and aesthetics through its large variety of colour palette.
Materials play an important role in the way façades are built and executed. Jayanand Potdar, COO, Godrej Properties, says his observation has been the appealing façades that are made out of concrete. “Glass and fibre glass are the most popular material. The second best that works well is aluminium in the form of sheet, composite panels or extruded sections. Wood and manufactured stone tiles are gaining momentum and can offer a natural look to the building. What must matter in all this is the ground work for creating the façade since that execution happens towards the tail end of the project and there are safety issues to be considered.”
A façade design is not just a magnificent architectural result, rather a result of well thought practical design satisfying the aesthetic need, and at the same time providing an energy efficient building. A building façade design has significant impact on the day lighting performance of the interior spaces. It is a result of a sustainability and performance consideration. Jaswinder Sandhu, executive VP, EPC, Oberoi Realty, says, “The façade is one of the most significant contributors to energy consumption and the comfort parameters of any building. To achieve a sustainable and high-performance façade, the designer should take steps to ensure that the environmental factors (heat, light and sounds) and energy efficiency strategies are integrated with the design process. Parameters to consider are orientation of the building that determines its exposure to sunlight, material selection, heat transfer and vapour infiltration, thermal comfort and daylight.”
It is imperative that all components of the façade work together to regulate the indoor environment, responding to heating, cooling, ventilation and natural lighting needs. Energy efficient buildings have low heat gain and by keeping fenestration ratio below 35% and appropriate shading, one can achieve the same. High performance glazing specifications should be used by means of DGU (double glazed unit) with low emission coating (low-E). The use of high performance glass increases the initial cost of construction but reduces the cost of operations by decreasing HVAC load.
Betting on performance
Façade fabricators are highly passionate about demonstrating how modern architecture and buildings can utilise façades to enhance building designs. Kapil Chikodi, head, business development, Glass Wall Systems, says, “Most of the innovations coming in have been in the form of double skin façades. Architects and clients have realised that variations in weather conditions and rise in temperature can be hazardous for façades. New engineering has emerged in terms of design mainly in composite or one system. For eg, shading devices, perforated sheets, plenty of fringe and other elements are also posing a challenge that allows us to incorporate in one system.”
He adds that with energy saving as the main criteria, users want to cut down on artificial lighting. Developers and users are also keen to deploy solar power even for common lighting areas in the building.
Speaking about the leaps the industry has made, Antony John, engineering director, Schüco India, says that the new National Building Code for the first time defined the guidelines in terms of the glass and support structures that were non-existent earlier. “We followed the British Code or the American Code or the Australian Code depending upon the location of the consultant. New codes are being introduced specifically for the façade industry. From our perspective, we have been aligning ourselves with BIS. We would like to bring in German engineering into the Indian constraints. It is not enough for a product to be good, but should also be fabricated, assembled and installed in the way it has to perform.”
Agreeing with this, SN Revankar, GM, design, Salarpuria Sattva, says, “Façade selection is done on four major elements, namely, wind load, height of building, architectural aesthetics and operation-maintenance ease. Completion timelines play a vital role in system selection to get speedy fabrication and installation. Efficient use of façade and fenestration must consider building orientation, sun path, directions, glare, glass parameters in terms of U-value, solar heat gain co-efficient (SHGC), internal/external reflection, etc. Also the sustainability parameters like LEED also should be studied.”
In terms of material selection, Satinder Chawla, MD, Span Floors, says, “In wood facade, a key design trend is the revival of the ancient Japanese technique to preserve wood with a modern twist. It is known by the name of Shou Shougi Ban. Essentially the wood (mostly cedar) was charred and then oiled to increase life and resistance against fire. With the Outwud brand, our focus is on patented vulcanised processing of wood which increases aesthetics, stability as well the durability so that it can handle the outdoor weather conditions in India.”
Better than the best
Façade design must consider building orientation, sun path, directions, and glare. Appropriate fenestration should be provided for better light ingress. For glazing, glass parameters should be studied in terms of U-value, solar heat gain co-efficient (SHGC), internal/external reflection, etc. Sustainability parameters like LEED must also be studied.
Navin Keswani, MD, Aluplex India, says that there are four primary elements to high-performance façade systems. The system by itself should be structurally adequate and manufactured with aluminium extrusions that are developed or designed and engineered with good structural adequacy to stand wind loads in that particular city. The second part that improves the efficiency is selecting the correct glass in terms of solar radiation properties and the co-efficiency of the glass and its installation properties with respect to double glass and acoustics. “A façade is primarily supposed to be faultless design proof and tender specified façade must be correctly produced, manufactured and delivered resulting in zero maintenance. The maintenance factor comes in to at three different stages, if there is external damage and impact, if there is a failure in the hardware, and thirdly when cleaning the façade,” he adds.
Explaining how unique façades are made, Raman Sapru president, EPC, Omkar Realtors & Developers, says, “At Omkar 1973, we have installed a unique façade in a super high-rise building which had different curves making it even more complex. The project has a curved stack joint with curved unitised panels and the glass had to be curved in a tolerance of +/-2mm along with a 220mm curved aluminium profile; both of which had to be imported from China to meet the required quality standards. The railing on the balconies was installed using a unitised system making the installation fast track. The unitised panels were even curved with ACP Alpolic panels and special machinery was imported. It was India’s largest façade project of 150,000m2 with over 3,000 tonnes of aluminium, 65,000m2 of glass and 70,000m2 of ACP imported from Alpolic, Japan. The installation was completed in a record time with over 36,000 unitised panels manufactured and installed in 12 months making it the fastest project in India; and possibly one of the fastest in the world.”
The façade and fenestration contractor must attend to the need for proper mounting of the outer frame which is critical for performance. There is a need to comply with all known material technical standards and specifications when designing, manufacturing and selecting façade, windows or doors. Debashis Roy, VP, KK Holding, says, “The world is heading towards renewable energy and in context of façade, there is a huge chance of producing solar energy. The problem of producing solar energy from glass is visibility. Solar cell blocks the visibility and offers maximum 30% visibility. To overcome this challenge, researchers are working on producing glass that can produce electricity. Scientifically, a transparent solar panel is an oxymoron. Solar cells, specifically the photovoltaic kind, make energy by absorbing photons (sunlight) and convert them into electrons (electricity). It has not yet been commercial used but I am optimist and as a responsible contractor we will be able to produce energy through façade.”
It is well known that developers allocate a certain budget for façades and fenestration. But a company like Godrej Properties left no stone unturned to construct the Godrej BKC façade, says Pankaj Keswani, MD, Alufit India. “The façade was completed in a record time of about 14 months. The façade has a unique architecture and has aluminium extruded beak forming a grid to encompass the high performance glass. The sunshades serve the purpose of shading along with fire access panels that were bottom hinged to comply to the fire codes. The beak covers the columns from the outside as well as at every 4m level and the beak elements jutting out between 600-1200MF. Normally, with different kinds of beak elements it’s done in sheet, but we engineered it in extrusions. About 68 extrusions were developed only for the beak element. It incorporates a variety of sustainable features, including an all-glass, high-performance façade that mitigates heat and radiation while providing natural daylight and expansive views.”
At a time when budgets for façade could hover around Rs 300 per sq-ft, the team of Godrej BKC had kept aside Rs 1,000 per sq-ft. Keswani says, “Normally, developers work on one or two elevations that overface the back, but here the client spent over and above on the beaks. They were also particular about the glass and one that would offer comfort even in peak summer. We finally zeroed in on Saint Gobain SKN 144 which is a high performance glass. The project also has sun shading louvers besides the beak element there are four louver blades which works as a sun shade.”
Kushal Bajaj, executive director, Geeta Aluminium, says, “We need institutions like IFT Rosenheim here to set proper guidelines not just for window professionals but for developers and architects as well. It can provide training and knowledge to professionals by ensuring the pre-requisite checks such as trained man power, basic set of machines and space availability to ensure quality output. Guidelines should also be given to developers not to purchase below par products so as to meet budgets but also maintain standardised window sizes for long run profitability. Since windows are the last product in a building to be bought, builders opt for cheaper products and could compromise on quality.”
Sundar Rajan, head of projects development, Shree Naman Group, sums up saying that ultimately a detailed study of look and feel of the building in terms of architecture and respecting the structure to hold that architecture needs to be carefully done. “Factors such as safety, weather conditions of the location, water resitance of the façade, details of the elevation worked out by the architect and the structural engineer play an important role. Façades need maintenance to a certain extent such as cleaning and that the O&M must take care of,” he adds.