Perforated Façade Design

revisions. Yet, there is a lot of work to be done in terms of cladding material, since this component of the project is still incomplete.

We need 2-hour fire resistance in cladding for fire separations smaller than 3.7m, according to NBC.

The cladding material used in other regions of the world, where building density has grown and fire separation is less than 3.7m, is EN13501- 1 grade A2 – s1, d0. These materials don't need to be tested for two hours since they won't catch fire and there won't be any smoke or droplets. Only Firewall A2 should be used for cladding in countries like ours, where cities are ancient and unmanaged, with heavy population densities.

Different fire classifications and certifications, such as ASTM E 84, BS 476 Part 7, NFPA 285, and BBA, are followed by each country or region. Project: St.Regis Hotel Location: Mumbai Client: Pallazio Hotels & Leisure Ltd. Architect: P G Patki & Associates Consultant: Axis Façade Consulting Type: Hospitality Area: 29,000 sq. m; Floor: 32 Scope of Work: Unitized Curtain Wall. Solid Aluminium Cladding, Aluminium Louver Unitized Glazing, Open able Punch Windows, Smoke Seal

THE MARKET FOR CLADDING MATERIALS

In India, consumer knowledge of fire-resistant cladding is fast increasing, which is having a beneficial influence on the industry. The various choices of fire-retardant cladding alternatives are being influenced by changing needs. At the moment, the market offers a wide range of fire retardant HPL panels, many of which are also Green-guard certified. This qualifies these goods for usage in 'Green Buildings' as well as other sensitive locations including schools and hospitals. The visual appeal as per the architectural objective of a structure, the environment of the region where the project is located, the cost and requirement to safeguard from fire for a particular time, and other factors influence the selection of fire-rated/retardant or resistant materials for cladding.

ROUNAQ. K. CHOUDHARI

Director, Glass Wall System (I) Pvt Ltd

ABOUT THE AUTHOR:

At a young age, Rounaq Choudhari is not only a successful entrepreneur but also looks out for society as a whole. After obtaining his Master’s degree from the University of Bath (UK) and gaining handson experience from the bottom up, he branched out on his own and became a Director at Glass Wall System India PVT LTD. Rounaq is at the forefront of the façade industry and an innovator at the age of 24. He joined the business at the age of 22 and has successfully managed and completed various projects in just 1 and a half years, achieving something at his age that never happened before in the façade industry. He is a quick learner and very passionate about his work. He is always striving to set up a trend in futuristic technology within the building façade industry. He has also been successful in executing the “World’s Largest Smart Glass Project-Bagmane Rio.”

Perforated Façade Design

Afaçade is the most striking elevational feature of a building. A good play of volume, scale, light, and shadow constitutes an impressionable façade design. The façade is an architectural element that enhances the visual aesthetics and indoor environment of the structure. With the advancements in science and technology, modern-day architects have been experimental with façade designing. New materials and computational softwares have made it easier to explore new façade design concepts.

Glass-cladded façades have been a long-standing choice for elevating building elevations. But, the suitability of glass in the tropical weather of India has been questioned because of its heat absorbing and light-reflective properties. The excessive use of glass in façade designs created the urban heat island effect. A glass façade traps and reflects heat thereby impacting the micro-climate and increasing local temperatures. Hence, glass façade buildings consume more energy to support ventilation and cooling thus increasing their functional costs.

However, there are promising alternative solutions to glass façades that are now taking over the industry. These include parametric, vegetated, and perforated façades which have a sustainable and tech-integrated approach to their designing. While the central idea of a façade is to make the building stand out, it should also improve the functional productivity of the

Perforated building façade; Image source: Dezeen

Jali building façade; Image source: ArchDaily

building based on its purpose and location. Hence, these alternative façade ideas are adopted with the intent of creating climate-responsive and contextual designs.

APPLICATIONS OF A PERFORATED SCREEN

Perforated screens find applicability in both indoor and outdoor spatial designs. Their ability to create privacy while maintaining visual connection makes them suitable for manifold purposes. In terms of exterior applications, perforated screens can be used as façades like an artsy blanket covering the building. Perforated façades provide the liberty to manipulate scales and volumes by playing with the opening sizes.

The suitability of perforated façades cannot be compartmentalized for any building typology. A perforated façade can be designed for residential, institutional, commercial, hospitality, and healthcare buildings. The design flexibility of perforated façades provides them the freedom

Perforated façade; Image source: Archro to be customized according to the building’s use and purpose.

PERFORATED FAÇADES

The Perforated or Jali façade has become a designer’s favorite because of its passive cooling benefits. In traditional Indian architecture, intricately carved wood and stone jali is significant elevation element that is suitable for the country’s tropical climate. The use of jali screens can also be traced back to Mughal architectural influences in India. The medieval age buildings in Rajasthan and Delhi are excellent examples of intricately carved and latticed jali façades.

The present-day jali façades are mostly linear and geometric in form. Louvered façades can also be considered as an extension of perforated façades because of the similarity in their functional mechanism. Metal and brick are widely used for the construction of jali façades today. A perforated façade provides a continuous design language to the building by wrapping or enveloping it completely.

The installation of a perforated façade involves an uncomplicated process. The prefabricated or

Venturi effect; Image source: ASCE Library

precast perforated screens can be installed directly to studs or an aluminum frame.

MECHANISM OF A PERFORATED FAÇADE

A perforated façade helps in regulating the building ventilation and indoor temperatures. It controls the entry and movement of air throughout the building by allowing for strategically designed openings based on the principles of the Venturi effect. The air passes through perforations that have a funnel-like cross-section; the smaller one being the air inlet and the bigger one being the air outlet.

This mechanism assists in increasing the velocity of air through diffusion. The inlet and outlet are shaped variably to ensure that the air in the windward direction moves through the building towards the leeward direction. The appropriate angulation of openings also protects the building surface from getting drenched by rains. wBENEFITS OF

A PERFORATED FAÇADE

Perforated Façades are versatile because they allow room for creativity. It is feasible to explore materials, colors, and patterns in perforated screens. With perforated façades, it is easier to blend the natural landscape around the site with the building.

One of the greatest advantages of a perforated façade is that it provides privacy along with transparency. The small perforations or openings make it possible to build connectivity outdoors while maintaining the required seclusion. A perforated screen creates the necessary visual barrier that makes the user feel secure and creates a resilient indoor environment.

Metal jali façade; Image source: Dezeen

Geometric perforation pattern; Image source: UlmaArchitectural

Energy Efficiency is another upside of using perforated façades for a building. Since a perforated screen is a passive cooling design element the energy invested in providing mechanical ventilation can be saved. It improves the building performance by limiting exposure to the sun and thereby effectively bringing down the running costs. Perforated façades help in achieving design sustainability with energy optimization. Sustainable architecture elements such as vernacular architecture, recyclable and renewable materials, and passive cooling can all be incorporated through an energy-efficient façade design.

Metal is a durable lightweight material predominantly used to create perforated façades. It does not considerably increase the dead load of the building. Since metal is malleable, it can be s haped into any form to suit the design sensibilities of the architect. It is also recyclable which reduces the demand for new materials resources. Another elevational benefit of a perforated screen is that it can be backlit. The frame of the perforations can be enhanced during the night making the building stand out in a busy urban landscape.

Perforated façades find wide acceptance in India because of their suitability for the local climate and architectural comfort. The reference of traditional jali elements in Indian architecture makes perforated façades a familiar design element for Indian users at the grassroots level. The perforation design can be modified to suit the needs of urban as well as rurban-built environments. With such large-scale applicability and acceptance, perforated façades have the potential to redefine façade designing in India.

CASE STUDY

CITY HOSPITAL, GORAKHPUR

The City Hospital, Gorakhpur is nestled within a humble urban fabric. The city maintains its originality through vernacular architectural elements and cultural representation. Thus, the built environment of Gorakhpur appears to be in a transitional process from traditional to modern.

The design of City Hospital by Ingrain Architects and Urban Designers identifies these characteristics and builds from there. The design concept of the building was perceived with the intent of creating a landmark building that is contextual yet modern and economical.

Built in 2017, the City Hospital, Gorakhpur is a 5-floor state-ofthe-art multi-specialty hospital for cardiac and neurosciences. This 125 bedded hospital spreads over an area of 55,000 square feet. It accommodates a 16 bed Intensive Care Unit (ICU), 8 OPD cabins, 3 Operation Theaters (OTs), a Cath Lab, a Cancer Diagnosis Unit, pharmacy, and other allied administration facilities. A rooftop canteen has also been designed to provide an eating area for patient attendants and relatives.

The hospital is not centrally airconditioned to create an energyefficient design. It works on a semiair conditioning module where only the medically sterile areas are mechanically ventilated. The other areas of the hospital are naturally ventilated through openable windows. They are provided with split AC units to be used as and when necessary. This is considered to have helped significantly bring down the running cost of the building.

Ingrain did not want the building to have a glass façade because that would make the building appear alien in Gorakhpur’s urban setting. To respect the local context and climate, the architects proposed a perforated façade with openable windows in the external wall. The hot and humid climate of