ARCHITECTURE AND SUSTAINABLE DEVELOPMENT, Proceedings of PLEA 2011, Louvain-la-Neuve, Belgium (July 2011) ISBN xxx-x-xxxx-xxxx-x - ISBN (USB stick) xxx-x-xxxx-xxxx-x @ Presses universitaires de Louvain 2011
The poetics of civic light in Le Corbusier‟s Assembly building at Chandigarh. ABSTRACT: The art of expressing architecture through ‘poetics of light’ was mastered by Le Corbusier during his career. Assembly building at Chandigarh, an important Civic Building built by Le Corbusier with emphasis on the creative use of daylight and sunlight has rarely studied in detail. This paper focuses on the critical qualitative and quantitative studies of the luminous environment in the Assembly Building by investigating Le Corbusier’s lighting techniques and the method of transferring his artistic ideologies into reality with light as one of the key architectural elements. Much can be learnt from Le Corbusier’s buildings which mainly use daylight as the primary light source to create the dramatic luminous environments. The research data obtained from this study are useful references for the design professionals to understand the dynamic interaction and sensitive balance between form, space and light in architecture. Keywords: Poetry, architecture, daylight.
1. INTRODUCTION 1.1. Background Chandigarh was a new town developed after Indian independence with the progressive ideologies proposed by the first prime minister of India Mr. Jawaharlal Nehru and Le Corbusier. The State Legislative Assembly at Chandigarh, an important Civic building was designed and built during the same time as Le Corbusier designed the other three religious buildings, Le Tourette, Chapel at Ronchamp and the parish church of saint-pierre, Firminy. The Church at Firminy was completed 41 years after his death by French architect Jose Oubrerie. This paper aims to investigate the luminous environment of Assembly building in Chandigarh and compare its lighting strategies with the Church at Firminy which has similar built form and design ideologies. 1.2. The Indian Context
access for the sun rays to enter the building on particular days. He has also related this phenomena to the Hindu temples in which the deity is illuminated with direct sun rays at particular days of the year. Le Corbusier used symbolism to demarcate the “Indianess” to the building by introducing elements on the roof of this parabola. The horns of a bullock (fig2) and the moon and the sun paths depict the intense relation of Indian tradition to the cosmic beliefs.
Figure2. Le Corbusier’s Sketch book and the Assembly building. From – Phaidon Editors (2008), Author (2011). 1.3. The Legislative Assembly Building, Concept and Ideologies.
Figure1. Fatepur Sikri and the Assembly building. From- Jencks (2000), Author (2005). Chandigarh has a seasonal monsoon rains lasting no more than 4 months. The temperatures rise up to 45 degrees Celsius in summers. Le Corbusier‟s first visit to India was in the summers of 1950. The idea of the Capitol complex was developed by taking inspiration from an old Mughal town of Fatepur Sikhri in Agra a city near Delhi (Fig1). Le Corbusier was fascinated with the fact that Indians were connected to the cosmic occurrences to such a great deal. He had visited the Jantar Mantar (Fig1) which is a physical solar clock built by precise understanding of the solar geometry and the sun‟s movement and it also displays time. Le Corbusier took inspiration from this „solar clock‟ precedent and developed a design which would respond to the solar trajectory and allow
Le Corbusier designed the assembly at Chandigarh as the centrepiece of the proposed Capitol complex and used architectural elements to display an identity and precise function inside the building. Curtis, states that as at Ronchamp and Le Tourette, Le Corbusier explored the Mythical qualities of light and darkness in the Parliament Building [1]. Light hence can be noted as an important design element in the conception and evolution of the building. The building showed a complete absence of the parabolic form in the initial designs. A box was proposed with the arches on the face to commemorate the central plaza facing the high courts.
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Figure3. Le Corbusiers sketches from Foundation Le Corbusier (2008). The composition of the roofline determines the profile of the building with the triangular skylight of the Governor‟s chamber, The Parabolic roofline of the Assembly Chamber and the cube containing the Lifts. A metal sky bridge connects this box with the parabolic dome of the Assembly maintaining a relation between the forms. (Fig.4) The new design showed the arches been replace by a huge gutter.
Figure4. Section through the chamber. From –Boesiger (1995).
assembly
1.4. The Journey to the Assembly Le Corbusier planned the areas around the main assembly chamber and located the forum as the central enclosed space, where the light dramas could be experienced before entering into the main assembly gallery. It is a noticeable space which creates a unique interplay of space and light for each step of the travel towards the grand chamber of assembly. To study the poetics of light in this space, the luminious environment is analysed qualitatively and quantitatively. For the purpose of this study the visitor‟s path to the Assembly chamber is demarcated on the plan. The notable drama created by the light is recorded and analysed to understand the impact of the luminous environment on the user. It can be observed that the delegates would normally use two paths to reach the chamber (Fig.4)
second path is entered from the same western face of the building but takes an anticlockwise turn towards the ceremonial door. The second path is also joined midway when the delegates use the ceremonial door moving circular, anti clockwise towards the east of the chamber.
2. METHODOLOGY The qualitative analysis was carried out to explore the effects of light inside the spaces of the building. The identification of Le Corbusier‟s lighting techniques used in the assembly building was carried out with the help of tonal sketches. This method was adopted from the study conducted by Lau (2000) for the Monastery of Le Tourette. The technique and the methodology of the typological summarising the light effects are acknowledged to Lau [3]. Physical model test by using heliodon revealed the daylight behaviour on particular days inside the assemble chamber. Computer simulation of the luminous environment inside the assembly was also conducted by using the software Autodesk Ecotect 2009. The available photographs and the drawings of the interiors and the sketches from the previous site visit helped gain extra inputs to the construction of the physical and computer model. The daylight measurement plane was set at 800mm form ground surface. Zones were formed according to the light typologies and were designated according to the function it carries. The zones demarcated is as follows (see Fig.5), Zone 1: The Forum Zone 2: The Assembly Chamber – Hyperboloid Zone 3: The Governor‟s Chamber- under the tetrahedron. Zone 4: The Office areas on surrounding the Forum. The daylight studies were carried out by using Radiance, a light simulation programme plug-in for Ecotect which can provide more accurate daylight performance prediction results.
3. LUMINIOUS ENVIRONMENT ASSEMBLY AT CHANDIGARH.
OF
Qualitative analysis of light inside the assembly building The analysis of the light dramas shows that four distinctive types of light have been introduced to the offices and to the forum and finally to the assembly chambers: 1. Balanced light. 2. Discrete light (light beam). 3. Ceremonial light (light beam entering the space at desired times). 4. Reflected light.
Figure5. Plan showing the journey to the assembly chamber. From– Boesiger (1995), Author.
3.1. Balanced light.
The first path commonly used by which the delegates enter through the door on the west or from the ramp at the lower levels circulates clockwise to a low height dark passage leading to the chamber. The
The Forum is a transitional space between the outside and the enclosed auditorium. Evanson, while describing the forum states that lofty, dramatically illuminated, seemingly scaleless in visual dimension, this space is one of the noblest in modern
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architecture, infusing some of the serenity and exaltation of a cathedral with excitement of a great concourse [4]. It is illuminated by two major light sources: the clerestory windows on the intersection of the wall and roof and the Occuli on the roof slab. It can be said that these light sources inside the forum act as „Fill light‟ and the „Key light‟ of illuminations for the whole space rather than an object. (Fig.6) The space under the triple height forest of columns is used for informal gathering of the delegates outside the assembly. The fenestration design suggests a clear intention of avoiding direct sunlight.
3.2. Discrete light (light beam). Discrete Light is used in the forum with the puncture in the roof. This “Occuli” is placed at the centre of the forum which acts like a complementary key light source to the clerestory window. (Fig.9) The sudden shaft of light penetrating the otherwise mundane space enlightens ones mood and dramatise the luminous environment. Even though it does not focus in particular towards any object, it brings back the memories of the Hagia Sophia at Istanbul which Le
Figure6. Forum area. From – Phaidon Editors (2008), Sections from author (2009). The sketches captured the cinematic views of the journey and (Fig.8) shows the upper floor flooded with daylight and the ground slab in dark shade. To dramatise this space, Le Corbusier painted the ceiling black and the floor was finished with polished granite. The floor helps reflect daylight into the interior. The clerestory windows act as the source of fill light to this area while the key light is provided in by the Occuli.
Figure.7 Roof of the two chambers. From– Boesiger (1995), Author. In the Governor‟s Chamber which sits inside a square enclosure with a tetrahedron roof opening facing the north. (Fig.7) The north side openings always prevent the direct sunlight. The triangular fenestration has vertical fins similar to the ones used in Le Tourette. They are denser at the eastern side. Thus it can be noted that there is a clear intention to illuminate the chamber with adequate ambient light but no glare which is required for visual comfort in the working environments. The balanced light is uncluttered and emphasises more on creating a mood for calm and undisturbed atmosphere inside the forum.
Figure8. Sketch views and Simulated images of the forum. From- Author. Corbusier had visited in his early days (Corbusier, 1989) [5]. This discrete light illuminates the floor of informal discussion and leads the way towards the assembly chamber. The occuli being at the start of the passage makes area brightly lit.
Figure9. Forum area. From – Phaidon Editors (2008), Sections from author (2009). 3.3. Ceremonial light The Cerimonial light was used as a dynamic design element in the building. The light responds to the sun position and interacts with the users. This light enters the assembly area to commemorate special days. (Fig.7) The ceremonial light was earlier intended to touch the Ashoka pillar at the speakers th table; inside the parabolic assembly on 26 January (Indian Republic Day) by mechanically opening the roof itself but later the idea was found to be unrealistic and not feasible. Le Corbusier then designed the roof at an angle to allow beam of light penetrate into the space on the equinoxes and the winter solstice of the year. The roof shows three fixed openings with ornamentation indicating the ideologies of Le Corbusier. They also act as the sun shades to guide
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the light enter the dome at desired times of the year only. The light drama in the assembly was tested on a heliodon and the results are summarised in figure 10.The heliodon tests show that the building was designed to take in the winter sun and avoid the summer sun as the local climate in Chandigarh is hot nd and dry. It can be seen on the summer solstice (22 June) the sun is exactly above the openings and the roof aperture was profiled in an angle to avoid any direct solar ingress. (Fig.10)
Figure10. Identification of Dynamic and Static Zones of Illumination inside the parabola.-From Ford (1996), Author.
panels to give a uniform light effect and create an undisturbed ambience (Fig.11). The dome is coloured with bands of red at the bottom and yellow at the centre. The upper half of the dome is left uncoloured and also without any acoustic treatment. Le Corbusier‟s design intends to reflect the relation between human and the sun which is expressed by the solar incursion of sunlight beam inside the chamber on particular days. 3.4. Reflected Light The offices located on the periphery of the building are illuminated glazed façade which are shielded by concrete Brise–Soleil‟s on the outer sides (Fig.12).The angles of the Brise –Soleil change in accordance to the orientation they face. They are at an angle of 45 degrees on south–west and north– west facades, but are at 90 degrees on the north– east side. They completely avoid the sun entering the office which may cause glare and overheating in summer. The Brise –Soleil help this area receive an indirect illumination desirable for office work. Le Corbusier experimented the use of these sunshades and use them in other parts in the complex.
The testing of the roof on Equinox shows a beam of light is allowed to enter the dome at noon. There is no direct sun inside the assembly in the morning and afternoon, while the middle and the upper fenestrations help to provide ambient light inside the assembly at other times of the year.
Figure.12 Brise –Soleil angles for the offices. From– Boesiger (1995), Author.
4. QUANTITATIVE ANALYSIS LUMINIOUS ENVIRONMENT
Figure11. The Results of heliodon testing showing the drama of light inside the assembly chamber. From- Author. On Winter Solstice, a light beam enters the dome and illuminates the walls of the parabola. The surface behind the Speaker‟s rostrum glows during this time. The circular form prompted the acoustic to be improved inside the assembly leading to the infusion of sound absorbent material along the slope of the dome. The artificial light is used behind the
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Fig.13 Isolux contour for the assembly building. From– Boesiger (1995) & Author. Zone1: Forum (Fig. 13) The light distribution patterns obtained from the computer simulation were organised with respect to the functions and the light typology. The graph in Figure 10 shows distribution of daylight in the building. The two prominent light sources in forum area show their presence in terms of the daylight
PLEA2011 - 27th International conference on Passive and Low Energy Architecture, Louvain-la-Neuve, Belgium, 13-15 July 2011
intake. It can be noted that the daylight factor is more at the central space of the forum diagonally opposite the west entry. It increases gradually as one moves through transitional path 1 towards the assembly (Fig.5,11). The light intensity varies from 262 Lux to 340 lux because of the Occuli at the roof level. The delegates are directed to move towards the assembly through the passage in which the light intensity is reduced to a miniscule amount before suddenly opening up into the assembly chamber where the light is taken from the skylights above. If one moves from the transitional path 2 as shown in (fig.9) then the circumambulation is from west to east in the anticlockwise direction. The light in the passages have relatively low intensity as one follows the circular path towards the east ceremonial door. The light intensity falls before its gradual increase near the entry to the assembly. The light levels were noted to decrease from 230 Lux to 53 Lux and again increase to 215 lux. The Light intensity again falls to around 119 lux before entering the chamber. The average daylight factor for the forum was calculated to be 4.4% under overcast sky conditions. The uniformity ratio was calculated to be 0.3 which is acceptable for an area intends for informal sitting and not for reading. The balanced light can be observed as the ceiling is dark and the floor is polished. The occuli plays an important role in maintaining the daylight level towards the northern part of the forum which otherwise will be a dull and dark space. Zone2: Inside hyperbola. (Fig. 11) The assembly dome carries three sky lights which allows the diffused light (other than direct solar penetration on key days of the year) to illuminate the sitting arrangement under it. The results show a uniform but a low daylight factor for the area. The assembly is aligned to the cardinal points and the openings at the roof level face south. The two balconies for the viewers which were placed on the concentric southern edge cast shadows on the floor below and do not allow the sunlight from roof to reach the floor at edges. The light distribution pattern indicates that there is a focus of light at the centre of the assembly. The average daylight factor is 0.84 % and the uniformity ratio inside the assembly is 0.5. The Daylight Factor is low inside the Assembly Chamber. The delegate Seats which face the north receives an illumination level of around 250 – 300 lux at the floor level. The central space which is occupied by the officials responsible for conducting the sessions of the assembly is the area receives greater intensity of daylight. The daylight factor was noted to be in the range of 0.2% to 0.4%. The average daylight factor was noted at 0.84% which can be considered to be low. Zone3: Inside the governors chamber - Under the tetrahedron. (Fig. 11) nd The governor‟s chamber or the 2 assembly is a cubical chamber where the delegates assemble under the tetrahedron projected skylight. The results show that the area is satisfactorily illuminated all
round the day. The square chamber has the roof light located at the height of 4.5M form the floor surface. The Daylight factors fall from the central region to the edge of the cuboid. The central space which holds the seating areas during the assembly is illuminated with greater intensity of daylight. The rows of the seats are designed at a slope as in case of the Assembly Chamber. The tetrahedron is added with Ondulatories, vertical fins which were designed to control the light intake. Considering the overcast sky condition for simulation, results show the Average daylight factor inside the chamber is at 1.93%. An isolux graph of the horizontal illumination levels inside the assembly shows that the lux levels at the edge of the chamber are close to 200 lux which proves the fact that the area even though shows less daylight factor has satisfactory illumination received from the tetrahedron. The maximum illuminance levels are 1000lux at the centre of the assembly and falls to 150lux at the edges. Hence the luminous environment can be considered as satisfactory for the function of the space. Zone4: Offices. (Fig. 11) The testing shows that the Brise- Soleil not only prevent the direct sunrays but provide a suitable illumination inside the office work area. The two column rows demarcate the floor space. The light intensity near the windows is presumably high but the light scatters uniformly inside the office. The Brise-Soleil angles are designed according to the solar altitude and azimuth angle. Considering the external weather conditions of Chandigarh it can be said that the fins (Brise-Soleil) are an appropriate solution for solar control. The illumination levels at the floor are at around 350 to 550 lux, which can be stated to be within the recommended limits. Even though the Daylight factor is seem to drop at the walls, the lowest light level stands at around 100lux. The Office at the South West shows an Average Daylight Factor of 4.8% which can be considered as a well day lit space. The Office at the North west shows an Average Daylight Factor of 2.5% which indicates that supplementary artificial light is required at times. The uniformity ratio was calculated to be 0.5 which shows that the office area is uniformly lit. The Office on the North East receives insufficient daylight as it falls on the northern side and never receive the direct sunlight on the façade. The Brise – soleil angel was intentionally kept at 90 degrees but this does not benefit much for the daylight ingress, but the on the contrary obstruct the light. The average Daylight Factor was calculated at 1.2% which implies that artificial lighting is required for most of the time. Daylight factor%
Assembly chamber Forum Offices SW Offices NW Offices NE Governor‟s chamber
Uniformity Ratio
Max
Min.
Avg.
1.4
0.07
0.9
0.06
14.4 8.8 3.7 5.2 4.1
2 1.4 1.5 0.1 0.8
4.4 4.8 2.5 1.2 2.06
0.4 0.3 0.5 0.1 0.3
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The table indicates the values recorded and shows its close proximity towards the actual required. 5.
COMPARATIVE STUDY BETWEEN ASSEMBLY AT CHANDIGARH AND CHURCH AT FIRMINY –FRANCE.
For the better understanding of the daylighting design strategies used in the Assembly, a comparative study was carried out between the Assembly and the Church at Firmny, France. The Church was completed in the absence of Le Corbusier and the building interior is mainly artificially lit which may not be Le Corbusier‟s original design intent. The results of the daylight analysis were categorised into different times of the selected days to understand the exact behaviour of the two light sources on the roof, the east and west windows and the peripheral openings. Morning Light, The “Orion” effect is seen to work when the sun is on East. The small star like apertures on the surface of the wall help achieve the effect. The alter shines on till 11 am in mornings and becomes dark after noon time. This effect seems to fade much earlier in winters and on equinox. Mid day Light, The two cannons start to emit light at noon time, lasting until 3pm. The focus is targeted towards the cone and gives a diffused lighting effect at the floor level. The design of these two cannons is similar to the skylights at the assembly, but they are insufficiently sized to illuminate the church interior. Evening Light,. The west Window plays an important role of keeping the focus on the altar. This focus gains importance on Christmas, Easter and St. Peter‟s day. This light is similar to the ceremonial light in Assembly at Chandigarh. Daylight factors from Artificial sky testing showed that the light levels in the Church at Firminy are too low for the visitors to rely on natural light. The lux levels drop from 15 to almost 8 lux at certain places compared to 1300 lux or more outside. The Daylight Factor is hence below 0.01% and the Uniformity Ratio is 0.06% which shows low luminosity and uneven light distribution. The low illuminance level inside the church makes the use of artificial light necessary during the day. The windows with the slope pointing downwards do not benefit the luminous environment of the church. The windows have same sun shading device on all the sides which does not allow the light penetrating into the interior. The Church at Firminy even though has similar daylighting strategies as the Assembly, its aperture sizing and design does not provide adequate daylight to the interior of the church. Le Corbusier‟s improvisations as seen in the assembly building where he sculpted the roof of the building in order to allow selective solar ingress is seen absent in Church at Firminy.
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6. CONCLUSION The success of the design of the luminous environment inside the assembly lies in the visual delight that has been achieved. The use of light as a element to illuminate the space in order to create various impacts on the users is evident from the study of the fenestrations and its designs. The light dramas created by the collective impacts from the balanced light, discrete light ceremonial light and the reflected light inside the assembly further enhance the visual environment. Le Corbusier designed the roof as a solar clock to allow the light to enter the area at particular dates and times and illuminate the speaker‟s area. This interaction between the occupants and the sun movements was sourced from traditional Indian architecture in which the deity is highlighted with sunlight beam on certain days inside the temple. These lighting technique used heightens the poetics of light in the Assembly. Although some areas tend to get dark during the day, it can be concluded that the emphasis on keeping the area cool from the scorching heat and using artificial light as a supplementary light due to the function was the priority. By comparing the luminous environments of Assembly and the Church at Firminy, unlike Ronchamp or Monastery of Le Tourette, the Church at Firminy does not evoke the poetic sensation. The lack of adequate daylight illuminance inside the church does not allow the luminous environment to be well daylit. Since the interior of the church is mainly artificially lit, the church looses the Le Corbusierian identity. By comparing these two buildings, it is evident that the drama created by natural light cannot be recreated by artificial light. Learning from Le Corbusier, It is important for design professionals to understand the solar geometry, trajectory and the effects of light on architectural forms and to use natural light as form giver in architecture.
PLEA2011 - 27th International conference on Passive and Low Energy Architecture, Louvain-la-Neuve, Belgium, 13-15 July 2011
7. REFERENCES [1] Curtis, W. (1986). Le Corbusier: ideas and forms. Oxford: Phaidon Press Limited. [2] Ibid [3] Lau, B. (2000). Luminious environment at Le Tourette. M. Phil. Dissertation. University of Cambridge: School of Architecture Cambridge. [4] Evanson, N. (1966). Chandigarh. London: Cambridge, University Press. [5] Corbusier, L. (1989). Journey to the East. London: The MIT Press, Cambridge, Massachusetts. [6] Jencks, C. (2000). Le Corbusier and the Continual Revolution. New York: The Monacelli Press, Inc., and Charles Jencks. [7] Boesiger, W. (1995). Le Corbusier et son atelier rue de Sevres 35. Bale Switzerland: Birkhauser. [8] Ford, E. (1996). The Details of Modern Architecture, Volume 2, 1928 -1988. London: The MIT Press, Cambridge Massachusetts.
Fig.14 Comparison of the daylight strategies at Assembly Building in Chandigarh and Church at Firminy.
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