Basically, temple architecture tradition of Kerala comes within the mainstream of Indian temple building tradition. Though, in the detailed articulation of its formal structure Kerala temple follows its own indigenous methods, the basic conceptions are not something different or extraneous from the total cultural developments of the mainland. It has been rightly observed that, "the temple as an institution, was an Aryan gift to the south India and that the so-called Kerala school is responsible only for covering the product of the Dravidian tradition."
Temples in Kerala used to be called in earlier times as mukkalvattom. Later they came to be called ambalam or kshetram or sometimes tali. The Kerala temple has srikovil as its main core, which usually stands in east-west axis and the plan may be square, rectangular, circular, elliptical or apsidal ground plan. Compared to the other temple styles in the mainland like Dravida, nagara and vasara, Kerala temple tradition has distinct characteristics especially in their formal structure. The architectural style of Kerala temples has an inherent simplicity which becomes very conspicuous when juxtaposed to the exuberance of the nagara, vasara and Dravida temple styles. In explaining this, influence of the natural environment upon the temple form has to be recognized along with the socio-historical developments. "In its original forms (architecture) is closely bound to the earth; is subject to the needs of society; is faithful to a programme. It erects its great monuments beneath a known sky and in a known climate upon a soil which furnishes particular material and no other." The basic relationship of the particular landscape which contains and holds the respective architectural form is a major deciding factor. Between the two, an organic unity and balance exist, which keep on interacting with each other. The environmental space which envelopes the architecture has a major role in the articulation of architectural form. This interdependence or the reciprocal relationship between environment and architecture can be further noticed in the construction of superstructures in Kerala temples. The two monsoons a year, and the moisture of Kerala weather has a direct bearing on the use of sloping roofs and the selection of raw materials by which the superstructure is being constructed.
The superstructure as a conspicuous example, shows an accurate usage of indigenous raw materials like timber and tiles to go with the climate conditions. Vast majority of temples have their bases built of granite, the walls made either of wood, bricks and stucco, or laterite; the sloping superstructure made of wooden planks, tiles or sheet metal on timber frames, are adopted to suit the high rainfall of the region. The roof timbers rest directly on the wall and coverage in gable form to meet at the top. The roofing material covering the timber framework is clinker built. It is made up of wooden planks overlapping one another, and covered over by clinker tiles or tiles highly heated in kilns with a glazy smooth surface that makes them water proof. The details given above substantiate that the raw materials used are meant to withstand the damp weather.
A truly indigenous contribution to the mainstream of Indian architectural tradition is the circular temples. The ponderous appeal of the sloping conical superstructure above the circular basement and walls is a clear testimony of the local idiom. Further, the edge of the superstructure comes down to join the socle in hugging the earth. The height of the superstructure is further softened by the circular moulded bands which function to accent down the verticality and emphasize the horizontality. The symmetry of the circle does not hamper fine nuances and modulations of the wall below. The spread of the conical roof above the wide cylinder, formed by the circular wall gives to the structure at the same time, a buoyant lift and a light winged aeriality. As a matter of fact, conical roof is the most satisfactory logical solution for the enclosure built on a circular plan. In few cases, the rhythm of the circular temples are further extended into elliptical shape.
In the case of rectangular or square based temples the four sided pyramidal roof is favoured. This has hipped ends on each of its two sides and the ridge of the roof running breadthwise is extended beyond the hipped end and carried with it the upper most part of the roof which thus forms a widely projected gable. "The concave curve, however so slight, was introduced to redeem an all too stark rigidity of angles, the convex curve such as might have resulted in this kind of roof construction, as it does, for example in the rural houses and temples of Bengal, found relatively little favour in Kerala." This tendency to relax the linear vigor and produce a slightly concave sky line, is a feature which is also found in Nepalese tradition.
Unlike the other architectural traditions in the mainland the design of Kerala temples shows a close similarity with the domestic architecture of the region. The earliest studies of Kerala temples include references to houses, with Stella Kramrisch pointing out the nalukettu and ettukettu houses, with four or eight wings, apartments or rooms, were built according to requirements of the classical Vastusastra, the architectural treatise. This closesness of layout between the secular and religious architecture are not in fact uncommon when we consider other traditions all round the world. In fact, the major architectural traditions like Greek, Japanese, Chinese and Islamic; show the evidences of this inter-relationship. Further, the first mosque in Arabia was designed after the prophet's house. In Kerala, however, logical hypotheses are needed to identify any sort of relationship between the two. The surviving Nair houses have many structural elements like raised foundations, wall and ceiling carvings, steeply sloping roofs, etc., that are reminiscent of temple architecture. The building materials used in the sacred and domestic architecture, viz., timber, laterite, brick and stucco are also the same, and thus create identical textural surfaces. Most conspicuous similarity between the two is in the presence of the inner courtyard that is open to the sky. The courtyard in both the cases is depressed slightly, but in the case of temple design it encloses the srikovil and provides space for circumambulation while in domestic types, it is entirely an open space except for the presence of a pedestal to grow the sacred tulasi plant. Functionally, space thus constructed within the architecture provides the interior with proper air and light. Here, the light is being enclosed in the architectural form and its rays, streaming forth at predetermined points are compressed, and attenuated and thus creating an air of openness within the architectural complex.
The development of structural complexity in later periods is managed without ostentation. Temple extends horizontally always hugging the earth, the structure emerging according to its precise functional needs, their spacing, creating an elegant rhythm and repose. Thus, the whole growth is organic and the final complex, bright, spacious and airy.
Scholars find that study of the stylistic development of Kerala temples problematic, due to various reasons. "Notwithstanding acknowledged early origin of good number of Kerala temples, especially those which had the special merit of having been visited and sung by the vaishnavite hymnist (alwars) siants of Tamil Nadu, the actual forms of the temples today belie their true antiquity by the renovations and modifications that have taken place from time, that obscure the original format."
Most of the temples, some with original adisthana, dating from eighth-nineth centuries of the Christian era, have considerably renovated superstructures, and as a result do not reveal much of their original forms. Moreover, the inscriptions in Kerala temples are often restricted only to the plinth of the temples. This is so because the very format of the temples largely using laterite, stucco and timber prevent epigraph from being engraved on the body of the temple. Thus, absence of any clear cut date of the subsequent renovations largely diminish their use as historiographic material, however, quite a few early records engraved on the temple mouldings can be cited.
Inscriptional evidences of the nineth-tenth centuries, clearly inform us of the beginning of temple building in Kerala. The cave temples of seventh-eighth centuries in Kerala on hard granite medium imbibe direct inspiration from Tamil country especially the Pandyas of Madurai through the passes in the Western Ghats which link Kerala with Tamil plains. Nevertheless, Kerala rock-cut architecture could evolve certain distinct mannerisms of its own. When we view the Kerala tradition of rock-cut architecture in the wider context of the mainland, i.e., in comparison to the rock-cut architecture of Mahabalipuram, Ellora or Elephanta, it is seen that the quantum of its contribution is minimal. This is due to the limitation of the very granite medium used. The Kerala temple tradition could, however, overcome this limitation in the subsequent centuries by making use of the indigenous raw materials like timber, brick and stucco laterite etc., which formed more versatile media, functionally as well as structurally.
Kerala cave temples, of which ten exist, are distributed accordingly in three groups. The southernmost group consists of those at Tirunandikara, Vizhinjam, Tuvarankad, and Bhutapandi. The central group consists of the temples at Kaviyur, Kottukal and Airurpara. The northern group form those at Irunilamcode, Trikkur and Bharatanpara.
All the cave temples in the southern group are examples of one called shrines, mostly enshrining a lingam. The best example of this group is the niche cave on a boulder at Vizhinjam, the capital of Ay rulers, a sea port and the scene of battles between Pandyas and Ay Kings. This cave has unfinished reliefs of Siva Kirata Murti and Siva dancing with Parvati. Some scholars hold the view that the bas-reliefs of Vizhinjam with their slender forms and rhythmic lines, show Pallava affinities.
From the central Kerala group, the one at Kaviyur (later half of eighth century) is a well finished example, the reliefs of which shows a mature plastic tradition. This saivite cave comprises of a shrine with a linga, an ardhamandpam and a pillared facade, all arranged axially facing the west. The floor of the cave is a few feet above the natural ground level and is approached by a flight of steps. The two pillars in the facade divide the breadth of the cave into three openings of an almost equal distance from one another. Walls of this spacious ardhamandapam contain reliefs of the donor or chieftain, a bearded rishi, a seated four armed Ganesa, and the dwarapalas. The style of these sculptures clearly shows an indubitable Pandyan influence. Sarkar points out the close resemblance between the dwarapala figure at Kaviyur and the one noticed at Sevelpatti and Tirumalapura, both in the Pandyan territory. Soundara Rajan also has the same opinion, and goes further to say that, "the examples of the central Kerala groups have strong Pandyan influence, except for two factors: the lingam is often of the arsha type with a tapering top and the pitha is of multiple cut stone masonry blocks and these distinctive features link them closely and directly with Pandyan country. There are the carving of ascetic like figures on the side walls of the mandapam, the provision of a separate pedestal for the niche carving is however, original to Kaviyur." The majority of the cave temples of both southern and central Kerala are inspired by the saivite movement like those of the Pandyan country. But there is at least one cave dedicated to Vishnu at Alagiapandipuram (Kanyakumari district).
Saivism dominated the northern group as well. The most important and the largest of the northern group is the one at Trikkur. Its outstanding features are its detachable lingam on a monolithic square pitha, the orientation of the waterchuts of the pitha to the north of the entrance direction of the cave, thus making the linga itself face east, the carving of the dwarapala in three quarter relief on the side walls of the cellar chamber and not on the outer walls flanking the door, the cellar being entered not by a single door but by a pillared facade with three bays whose pillars have a taranga or wavy corbel of the vaulted type. Ganesa sculpture in the northwest cellar wall shows familiarity of the artist with the Pandyan usages, and thus making the cave shrine ascribably to the early eighth century.
Unlike in other parts of the country, the origin of rock-cut architectural tradition and that of the structural temple tradition are more or less coeval in Kerala. Even from the very early stage, that is from eighth century, we get evidences of not only square and rectangular temples, but also circular, apsidal, and rarely elliptical temples. Nowhere else in India do the circular shrine constitute such a dominant type of ground plan as in Kerala. Vastusastras, known from about sixth century in the mainland, treat in detail the circular temples and their various types. Outside Kerala, however, very few circular temples are known to exist, although the walls of the earlier structural temple yet seen at Bairat, Rajasthan, of the third century B.C. is circular. In the medieval period temples of Chousat yoginies were built in the circular ground plan. These examples are found at Bairagat in Madhya Pradesh and Hirapur in Orissa. However, these temples are open to the sky or hypaethral in type, except for the cloistered space, which display the sixty-four forms of Devi.
The original source of the circular temple in Kerala is still a controversial issue among scholars. A number of scholars, like Sarkar holds the view of the Buddhist origin of the circular plan. He provides the evidence that the southern part of Kerala where Buddhism had a strong hold shows comparatively large number of circular temples. Another viewpoint in this regard is that circular temples with a garbhagriha surrounded by one or two rows of columns bear some similarity to the circular Buddhist temples of Sri Lanka, known as vatadaga. There is a strong tradition in Kerala about the migration of Ezhavas from Sri Lanka and these people might have popularized this type of architecture which in course of time got mingled with the Brahmanical tradition. Kramrisch on the other hand, holds the view of an indigenous origin. She mentions that the prototype of the circular temples has to be seen in the circular huts set up by some of the primitive people of Kerala. She points out two instances in this regard. The tribe known as Malampandaram lives in circular or conical huts, and the tribe known as Ullatas set up circular structures for ritual occasions.
Attention has frequently been drawn to the similarity of certain Napalese structures and the pent or multiple sloping roof of temples of Kerala, thus ascribing the origin of such superstructures to foreign sources. According to Kramrisch, no influence should be seen in the affinity of these buildings. In both the countries the perennial Indian tradition is living, and both are rich in the use of wood.Brown searches for links to Saurashtra and to Kashmir temples like Pandrenthan and Martand. In fact, temples having a square plan and a double or triple sloping roof exist in stone form not only in Kashmir from the eighth century, but also in Saurashtra of the Maitraka age. Vastusastra also classifies these temples and names them after mountain peaks Himavan, and Malayavan or Shringavan if there is but one peaked roof (Vishnu Dharmotra Purana 3rd, LXXXVI). Both Soundara Rajan and Sarkar hold the view that Kerala temples are local adaptations of the south Indian temple architectural tradition, and the divergences in the structural form were introduced primarily to counteract the heavy rainfall of the region. Bernier also endorses the same possibility. Sarkar moreover goes to the extent of saying that similarities with the Himalayan architectural tradition is a superficial one due to the use of sloping roofs on wooden frame.
The temples with apsidal ground plan of some of the Kerala temples, however can easily be associated in their structural similarity, with the Buddhist chaitya halls found elsewhere in the mainland. The origin of such structures could be ascribed to the Buddhist influence.
Before going into the actual discussion of the architectural phases, it is necessary to keep in mind that Dravida and indigenous Kerala types of architecture co-existed and had simultaneous development in the same land from the eighth century. The Dravida school of architecture shows a concentration in the southern part of the state, which from the very early period was under consistent Tamil influence.
In the north Kerala, on the other hand, a building tradition existed truly at home. As observed by Kramrisch, the origins of indigenous architecture may be in the tribal forms. Temple architecture of Kerala is classified into three stages of developments by H. Sarkar. The discussion below takes into consideration those three phases of temple architecture in Kerala.
