Research Paper (Façade materials)

Research in Architecture Aakash Paresh Godse Aayojan School of Architecture and Design, Pune

Research topic : To study derivations and variations in façade materials.

Abstract : Facades have always been a vital part of building design. Facades have a very deep impact on to the minds of the viewers as well as the end users of a particular building. The above research paper shows a significant information regarding the current trends in high rise building facades with respect to the facade materials. Buildings are considered to be the largest users of energy.

This consumption of energy can be reduced by a sustainable approach towards façade design and material selection for the same.

There is a large amount of deviations which can be seen in the façade materials. What started with the use of stone, bricks and mud in the early 18 th century has now lead to the invention of newer materials such a aluminium cladding panels, glass, Copper and brass finishes, ETFE etc. These newer materials are not only strong and durable, but are also easy to manufacture on large scale and easy to transport on to the construction site.

The trends in the façade are ever changing and mainly depend on to the construction technology, architectural design and availability of material in the market.

Keywords: Construction, Current trends, Sustainable.

Aim : To study how the material used for high rise building facades have changed in the due course of time.

Objectives: • • • • • • •

To study and understand the various aspects involved in façade design.

To study the change in expression of a building over a period of time.

To analyse the change with respect to changing materials and technology.

To analyze how and what lead to a change in the use of façade materials and construction techniques.

To carry out case studies of high rise building façades located in a same region/ city.

Doing a comparative analysis in order to arrive at the advantages and disadvantages of different façade materials.

To find out the current trend in façade design and material selection for the same.

Scope : Acting as a barrier between the inside and outside of a building and also creating climatic comforts for the users are some of the main purposes of a building façade. There has been a large amount of experimentation done in the façade materials. Various new materials have come up in the market which are more durable and strong as compared to those which were used earlier. The research would mainly focus on to the various new materials arrived in the market and the new construction techniques involved while constructing facades.

The data collected through research will help to build better facades which will act as an interface between the interiors and exteriors and also will respond to the surrounding climate. This data would act as a guideline while designing the skyline in terms of the material use and construction process.

Limitations : • • •

The study will include documentation of high rise buildings with respect to the façade materials used only.

Structures constructed in various times need to be selected in order to show a timeline of the transformation in material use for the façade.

Facades would be analyzed only in terms of the material use only.

Methodology : • • • • •

To understand in detail factors for analyzing a high rise building façade.

Performing multiple case studies, to study the effect of different types of façades and the material used for the same.

Case studies to be selected from one specific region in an urban area.

Doing a comparative analysis of the selected case examples.

Conclusions to be derived on the basis of case studies and data collected for the research.

Introduction : The building exterior or façade is the most crucial part of building design. The façade not only acts as an external covering or envelope of the building, but also gives a specific identity to it. People living in cities are exposed to streets every day. These urban streets are dominated by high rise buildings. The research includes study of facades with respect to the architectural character, materials used, surface finishes etc.

Building facades as an interface between matter of evaluation by the visitors who exterior imposes a very large impact on to various other aspects such as the material impact on to the peoples minds.

the interior and exterior space, is mostly the visit the area frequently. Therefore the building the peoples minds. Apart from the façade design, selection and surface finishes have a very deep

Facades have always been an element of experimentation and expression since the past.

Hence large amount of derivations and variations can be identified in façade design since the past up till now. The progress in technology and advancement in construction process has led to invention of numerous new façade materials in the market. What began with the use of materials such as stone, bricks and wood in the early 18th century has now transformed into the use of materials such as glass, aluminum panels, metal fabric boards, raw finishes concrete, stainless steel, copper, brass etc. These newer materials are not only

strong and durable but also have the ability to handle strong wind speeds and are much easy to install due to their light weight structure.

Buildings are considered as the largest users of energy and also are the greatest possible way of conserving energy. A façade design has the capacity to have a positive as well as a negative impact on to the environment. The façade is one of the most significant contributors to the energy conservation and comfort parameters of any building. It is not only the façade design but also the selection of material which determines whether the façade will perform or not. For any façade design there should be a proper selection of material so that the heat gain or heat loss in the building can be controlled naturally.

No doubt, façades are the most important building element from both the users and the architect’s point of view. They are the most difficult to design too since the perception of iconic and technologically advanced facades is changing frequently. Designers are researching and experimenting with new and complex façade forms and patterns. The glass aluminium facades are bygones now as we see a lot more new materials in the market such as rusted iron panels, zinc, copper and steel, even high pressure laminates.

Along with the materials that furnishes the look and feel of a building, technologies applied to facades are also changing. The leading-edge technologies play a crucial role in terms of sustainability and operational cost-effectiveness. Truly successful facades do far more than merely projecting an iconic image, they play a vital role in driving or transforming building performance, engaging with the external environment, significantly enhancing durability and reducing energy consumption.

Key characters of high performance façade A high performance façade is a façade that not just envelopes your building, but works with your building to give you optimum daylight, comfort, no glare and reduction of heat gain. An optimum high performance façade is always going to be one that shields you from the external harsh atmosphere, while at the same time not demanding you to turn on many high levels of air conditioning.

High performance façades effectively ensure a better working environment and can add immense value to the end user. It gives flexibility not only in design and design expression along with execution of façades in factory and on site but also facilitates cleaning, maintenance and replacements subsequently. Double skin façade buildings were first built during the first energy crisis as an attempt to improve building performance. The recent resurgence of efficient building design has renewed interest in this concept. Since the Green Building Council offered reward points for reduction in energy consumption, this strategy has been used to optimise energy performance of buildings.

Façade systems should address the management of glare and light, solar gains, acoustical considerations, ventilation, energy harvesting and more. Integration between the façade as a building skin being elevated to other building systems adds to the intelligence in building management technology. Façades that integrate electrical and plumbing services through closed-cavity systems or automated shading devices driven by sensory controls for electric and mechanical applications efficaciously widen the performance spectrum for building skin. It is critical that all the building skin components work seamlessly together to create a technically coherent solution, giving the designer a unique opportunity to display their concept, form, functionality and technological prowess.

In Indian market, low cost solutions in high performance façades will be a key criteria. High performance, in terms of energy efficiency and sustainability, will be the key driver in façade technology. In additional to modularity in façade technology, ease of production, installation and maintenance are essential characteristics of a high performance façade. In terms of key façade performance, it should be pre-tested and certified, especially against structural, air permeability, water tightness, and thermal, acoustic, seismic if required.

Two major types of façades exist: curtain walls and double façades. Both can contribute to a more optimal thermal comfort. The rising trend, however, is adaptive façades – an envelope that uses flexibility to actively regulate the indoor conditions and helps in increasing the energy efficiency of a building. Extrinsic control of these adaptive systems possesses the quality to combine (central) automated strategies with local control and individual user needs. Adaptive systems are most suited for the moderate climate zone, as a consequence of the seasonal variation between the need for heating and the protection against overheating.

Advancement in façade technology and materials Façade methodology has always remained complimentary to the structural systems along with other factors like climate and aesthetical preferences. With the inception of framed structures, precast and prefabricated façades came into the picture. The same factors are going to define the future façades.

The material choice and the combination would derive creative character of the façades – Steel, aluminium, zinc, tile, stone, extruded resin, ETFE and so on, the list is endless.

Aluminium and glass façade concept is now changing and a lot of ceramic, cotton steel, stone, thin stone cladding and other new materials are being used on façades. The material palate that is available is so wide– from high pressure laminate to solid aluminium core; there is aluminium foil on which one can paste just 2-3mm stone instead of using 20- 25 or 40-45mm stone depending upon what kind of stone it is. “We are using less stone, putting less weight on the building. With these recent R&D in façade technology, a lot of this material originally started off in aeronautics and in vehicle manufacturing and now they are making their way into façade engineering”. Today one can get more and more robust hardware from the best companies all over Europe, China and India that can take additional weight to get various types of window systems that are automatically or manually operated.

Kinetic façades are dynamic and ever-changing, rather than static. Building skin elements can be programmed to respond to climatic factors, impacting energy efficiency or solar heat, or for aesthetic reasons, such as an art installation. The Al Bahr Towers in Abu Dhabi uses a computer-controlled façade made of umbrella-like panels which open and close in response to the sun’s the wind movement to achieve optimal shading and light.

While there are many factors which require consideration in building façade, one of the most daunting one is – Choosing the right material. Also, the decision on the right façade material needs to be made after considering a range of factors like: •

Water-resistant

•

Energy efficiency

•

Aesthetics and texture

•

Eco-friendly

•

Durability

•

Cost

Trend setting façade technologies of the future – Catering to the demands of an ever expanding industry and innovative designers, the presentation shifts in its last segment to sensitising on the future technologies in Building Facades which will provide better efficiency, aesthetics and commercial value to the developments addressing a wider spectrum of issues covering the following: • Facades generating Power – Photovoltaic Glass Unit (PGU)

Building integrated photovoltaic’s capture the solar radiations and turn it into energy. A high level of energy generation (up to 12 percent efficiency) can be generated through Photovoltaic Glass unit. The advantage of this technology is that it is allowing the usage of fenestration part of the building as PGU’s provides transparency to the human eye upto 70 per cent.

• Thermally Dynamic Facades – Phase Change Materials (PCM) Facade, which responds in accordance with the variations in outdoor conditions. Thermally dynamic facades use phase change material wherein a layer of salt crystals captures the heat radiated by the sun and release it back to the environment during non-operational hours. The thickness of conventional materials used in buildings is much more than the equivalent heat capacity of a one-centimetre-thick PCM. • Biomimicry in Facades – Living Buildings Just like the surface of a leaf, the ‘skin’ of future buildings may react to external stimuli, opening, closing and breathing throughout the day through a system of ‘cellular’ openings that allow light, air and water in the apartments contained within.

• Facades Enhancing Outdoor Environment – Microclimate Impact Growing vegetation on the facade can potentially create a positive microclimate around the built form.

A microclimate is a local atmospheric zone where the climate differs from the surrounding area. The studies accounts that a reduction of approx. 2˚C can be achieved by using green vegetation around buildings compared to the surrounding ambient in composite climates like Delhi.

• Facades 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 facade or a greenhouse offers a potential to counter the toxins, VOC’s, microbial infections, etc. in an air-conditioned building.

• Façade Addressing Fuel Crises – Building Powered by Algae A classic example of this technology is BIQ building algae panels generating power where the algae is grown on facade and burned to provide an alternate energy source.

• Facades Addressing Food Crises – Hydroponics The idea that fruits and vegetables can grow with water, light and nutrients are 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 per cent for NO2 and 60 per cent of 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 in softening of the urban landscape and allowing buildings to seem more ‘natural’ and pleasing for the people.

Energy efficiency remains a primary challenge in today’s commercial construction industry. How important are energy efficiency gains from a building envelope is a topic that is gaining momentum amongst industry leading architects and design firms. In order to address a few paramount issues in the industry, with ever increasing pressure for the dual objectives of higher performance and improved payback calculation to stakeholders, innovative trends and forces shaping the future of building skin contain the answer of many unfolded domains.

Case study – In order to establish a timeline, structures constructed in various time zones have been selected.

1. Rajabai Clock Tower (1878)– The Rajabai Clock Tower is a clock tower in South Mumbai India. It is located in the confines of the Fort campus of the University of Mumbai. It stands at a height of 85 m (280 ft or 25 storeys). The tower is part of The Victorian and Art Deco Ensemble of Mumbai, which was added to the list of World Heritage Sites in 2018.

Rajabai Clock Tower and Mumbai University Library building is an ongoing preservation and restoration project of a Grade I heritage building at Fort Precinct in South Mumbai. The project includes architectural, structural, services and interior works, including making a future maintenance proposal for this 136 year iconic building in Mumbai.

This Neo - Gothic building was designed by Sir Gilbert Scott. The construction of the building began in 1869. The Library building was completed in 1874 and the Clock Tower was completed in 1878.

There are four different stones used in the construction of these buildings – Malad and Grey Green Basalt for the Masonry work, and Porbundar and Red Dharangdhara Stone for the architectural detailing. The Clock Tower with a height of 87m is an important feature of the building. The Library building has been designed with bilateral symmetry, and has features like verandahs or arcades, louvered windows, high vaulted ceilings were used. In addition to this, it

has the stained glass windows, Minton tile flooring and highly carved projected balconies, stone carved capitals with heads of Shakespeare, Homer, kings & queens provided the building with a unique character. The arched ceiling in the reading area is handsomely wooden panelled and the massive rosewood doors and partitions on the entrance lobby reproduce some of the best carved examples.

2. Kanchanjunga apartments (1983)Correa’s penchant for sectional displacement accompanied where appropriate by changes in the floor surface, is at its most elaborate in the 28-story, Kanchanjunga apartments completed in Bombay. Here Correa pushed his capacity for ingenious cellular planning to the limit, as is evident from the interlock of the one and a half story, split-level, 3 and 4 bedroom units with the two and half story 5 and 6 bedroom units. Smaller displacements of level were critical in this work in that they differentiated between the external earth filled terraces and the internal elevated living volumes. These subtle shifts enabled Correa to effectively shield these high rise units from the effect of the both the sun and monsoon rains. This was largely achieved by providing the tower with relatively deep, garden verandahs, suspended in the air. Clearly such an arrangement had its precedent in the cross-over units of Le Corbusier’s Unit habitation built at Marseilles in 1952, although here in Bombay the sectional provision was achieved without resorting to the extreme of differentiating between up and down-going units.

Whole structure is made of reinforced concrete. The building is a 32-storeyed reinforced concrete structure with 6.3m cantilevered open terraces. The central core houses lifts and other services also provides the main structural element for resisting lateral loads. The central core was constructed ahead of the main structure by slip method of construction. This technique was used for the first time in India for a multi-storeyed building. With its concrete construction and large areas of white panels, bears a strong resemblance to modern apartment buildings in the West. However, the garden terraces of Kanchanjunga Apartments are actually a modern interpretation of a feature of the traditional Indian bungalow: the verandah. In a bungalow, the verandah wraps the main living area.

3. Imperial towers (2010)The Imperial is a twin-tower residential skyscraper complex in Mumbai that is one of the tallest completed buildings in India. In 2010 its construction was completed and the towers were inaugurated.

Designed by architect Hafeez Contractor (Mumbai), The Imperial is built on former slum land in Tardeo, South Mumbai and is perhaps Contractor's most recognisable project to date. The project's use of the modern urban redevelopment model in which the building firm provides free land and rehabilitation to slum dwellers in exchange for rights for property development was the first implementation of this model on a large scale. The project is an example of success in the redevelopment of slum and cotton mill land across the city and across India as a whole.

The typical floor plan for the Imperial Towers has only four residential units within the hexagonal floor plate and above the 40th floor all units are duplex. All units have generous outdoor decks with approximately 150–270 degree views. For privacy the decks are located within the floor plan such that they do not overlook the other apartment units. A landscaped podium on the ninth floor provides a green space amenity for the residents.

The towers’ structure utilizes a flat slab design which gives flexibility to change the interior layouts of the units if desired by the occupants as well as provide a faster construction schedule. The lack of peripheral beams allows for maximum window heights. To express the verticality of the towers, the window glazing is fragmented from floor-to-floor at the lower levels, changing to double-height glazing higher up the elevation, eventually continuing up into the crown.

4. Lodha altamount (2017)– Lodha Altamount is a luxury residential building project of the Lodha Group and is situated on Altamount Road in Mumbai, India. The development was the tallest building in Mumbai. The development is under Lodha Group’s Luxury Collection. Altamount Road is ranked as the 10th most expensive street in the world.[1] Lodha Group acquired the area from the US consulate for Rs 375 crore, surpassing the bids made by Mahindra Lifespaces and TATA Housing. The previously existing Washington House, home to US Consul General, was a three-storey building, covering an area of 2,702 square meters. It falls under the Coastal Regulation Zone 2 and is listed as Grade 3 Property

5. Omkar 1973 (2020)Omkar 1973 will be one of the tallest structures in India. The 400-plus sky bungalows, ranging from 2,500 sq. ft. to 18,200 sq. ft. area. It will have a height of over 300 meters and an area of about 5,000,000 sq. ft. It consists of three towers scaling 81-storey, 81-storey and 76-storey. The project is scheduled for completion by Dec-2020. The project is designed by Fosters & Partners in association with a local architectural firm named DSP Design in Mumbai.

Equipped with modern amenities like an infinity pool, spa and several other outdoor activities, society is a deluxe place that offers urban facilities for a comforting and relaxing life. The well-appointed Omkar 1973 features aluminum sliding windows, POP walls, granite kitchen platform, concealed wiring, concealed plumbing, grand heighten lobby and all the high-quality raw material fixtures to ensure that you enjoy an extravagant lifestyle. Security being of vital importance, this is a gated community to provide a sense of worry-free and safety living to its residents

Façade materials used during various periods – • • •

19th Century – Stone, bricks, lime, mud etc.

20th Century – Concrete, Glass, Cement plaster etc.

21stCentury – Aluminium cladding panels, Double glazed façade, curtain walls, copper and brass finishes, UPVC & CPVC framing members etc.

Materials used for various case examples – 1. Rajabai tower : There are four different stones used in the construction of the facade – Malad and Grey Green Basalt for the Masonry work, and Porbundar and Red Dharangdhara Stone for the architectural detailing. Also stained glasses are used for the windows.

2. Kanchanjunga apartments : Mainly the exterior comprises of reinforced concrete walls. This walls has punctures made in it for the windows and balconies. The reinforced concrete wall is finished with an ochre color paint. The recessed balconies are painted with bright colors such as yellow and red.

3. Imperial towers : The façade comprises of a combination of Aluminium cladding panels and fixed glass façade. All the windows have a floor to ceiling height and are completely covered with fixed glass panels. The slab and column projections on to the external side are covered with white coloured Aluinium cladding panels.

4. Lodha altamount : The entire façade is made out of fixed glass panels. The parking floors at the contain a green façade with plantations done on to the exterior walls of the floors. The glass façade is designed in such a way that the mullions are inside and the groves between the two adjacent panels are filled with material.

bottom parking hidden sealant

5. Omkar 1973 : The building has multiple curves on to the façade. These curves are covered with either glass panels or with Aluminium cladding panels. These panels are custom made for this particular project. The residential units have projecting balconies on all the sides, hence the tower elevation mainly comprises of balconies and terraces.

The lower parking floors are covered with louvers in order to hide the cars.

Conclusion : The trends in façade are ever changing and do not remain constant for a prolonged period of time. The façades are highly influenced by the construction technology, available materials, architectural planning, climate etc. These factors play a vital role while designing and selecting materials for a high rise building façade. Although there are newer materials coming into the market, the older ones are still used for certain projects. Hence the overall life of a façade material is more.

The main reason for the change in the older façade material was their high weight and more period required for construction. The newer materials available in the market are light weight and are easy to install even at greater heights. It is also easy to produce these materials on a large scale and to transport them to the construction

site. These advantage lead to a sudden increase in the demand for the newer materials.

In earlier days the main intension of a façade was to show the power of a particular building or kingdom. But now the times have changed. The facades are now not just a symbol of power but also a way to achieve climatic comfort through a strategic and sustainable design. Not just the façade design but also the façade material plays a very vital role in controlling the climate. Selecting a proper material for any high rise façade has been taken into consideration now a days since the designing stage.

It is highly necessary for the design teams to now change there approach towards façade design. There are many practices still, which do not upgrade their knowledge regarding the advancements in façade design. The new architects and planners must be guided towards the new palette of façade materials available in the market.

References : Websites referred – https://architecturelive.in/rajabai-tower-and-library-building-mumbai-brindasomaya-somaya-and-kalappa-consultants/ https://www.thehindu.com/society/go-beyond-the-boundaries-of-buildings-60minutes-with-brinda-somaya/article23398766.ece https://www.archdaily.com/151844/ad-classics-kanchanjunga-apartments-charlescorrea https://thewhitecube.info/case-study-kanchanjunga-apartments-56/ https://www.magicbricks.com/imperial-towers-tardeo-mumbai-pdpid4d4235303239323637 https://www.lodhaluxury.com/ https://www.realtyscale.com/lodha-altamount/ https://www.omkar.com/ongoing-residential-projects-mumbai/omkar-1973-worli https://www.besconsultants.net/ https://www.ruukki.com/b2b/products/facade-claddings/facade-cladding-materials https://www.mgsarchitecture.in/building-materials-products/facades/1207sustainable-facade-materials-lead-to-green-buildings.html https://www.homify.co.uk/ideabooks/4145093/8-materials-perfect-for-exteriorfacades https://www.researchgate.net/ https://www.academia.edu/login https://mccoymart.com/post/challenges-faced-high-rise-facade-construction/