Why does the wooden architectural style of temple and other structures in Kerala stand apart in India?

Kerala temple, S.India  Alamy.com 

Above image: Wooden buildings typical of Kerala architecture in the Subrahmanya Temple complex close to Alappuzha in Kerala, India.............................

The Indian architecture, in particular, related to temples  is rich in tradition  and culture,  and the design, decorations  and the construction materials used vary from regions to regions. So are the configurations of buildings  and sculptures incorporated in the structural designs  in the respective regions.  While Indian temples  are made of brick with sand-lime mortar or hard stone locally available, Jain temples mostly use marble stones for reasons of fine interior decorations. The remarkable pillars in Jain temples have  intricate designs and the carved ceilings exude charm  and grandeur that is irresistible.

Ranakpur Jain temple, richly decorated marble pillars .travelogyindia.com 

In most of the Hindu temples of South India except Kerala the ceilings  over the hall (mantaps) or enclosures around the garbagriha (sacnctum) - prathkshana path  and other halls are  made of  hard stones in the form of rectangular slabs over granite beams supported by large  ornate granite pillars. Near the junction between the stone beams and the pillar  one can  see an  aesthetically designed s mythical animal - part lion, part elephant and part horse (invariably Yali ) or some animal sculpted in to the pillar; sometimes described as a  (part lion and part griffin) with some bird-like features. Yali, a motif in Indian art,  has been widely part of south Indian temple  sculpture and iconography. Depictions of  yalis are very old, but they became prominent in south Indian sculpture in the 16th century. Yalis are believed to be more powerful than the lion/Tiger or the elephant. Yali is also known as Vyala or Vidala in Sanskrit.  Images or icons of  Yali are  believed to protect and guard the temples and ways leading to the temple.

Nagara style of north India. mrpostmaster.blogspot.com/

Temple with Vesara style. officersiasacademy.blogspot.com

Nagara style ornate entrance frame and pillar sahapedia.org/

Dravida style Jalakantesvara Temple,Vellore, TN,carved Stone Pillar With Yali flickr.com

Dravida style, hall with sculptured pillars and granite ceiling, thegoodlifewithiq.com

 Hoysala Architecture, Halebid, Karnataka,  ornate pillar in.pinterest.com

Malebid emple, Karnataka team-bhp.com

Above image: Notice  the wide basement plinth on which the the temple stands. The basement is richly carved.  The main entrance has  beautifully carved Dwarapalakas on either side of the door.  Carved pillars and stone carvings dominate interior ane exterior.  The details of  stone carvings at Halebid  Karnataka in South India are amazing far beyond  the realm of imagination.

As part of Dravidian style, each pillar in the hall - manptap is designed this way through
 out other  halls as well. This type of design is common among the Dravidian-style temples 
of south India.  Nagara style temple in the north or Hoysala - style temples in Karkataka  
differ from the Dravidian style that  has tall toweres (gopurams) and spacious prathakshana path dotted with many small shrines all around, each housing a different god or  goddess.  Developed during the 5th century,  Nagara style  tower is minutely ornate gradually inclining inwards in a convex curve. In this type of plan, the projections are carried upwards to the top of the Sikhara, and thus there is strong emphasis on vertical lines in elevation. Stone pillars are ornate and devoid of Yali like mythical animal as we have seen in the south Indian temples. As for Vesera most found in the north and part of Andhra, it is hybrid one, a blend of Nagara and Dravida style. Many Vijanagara temples fall under this group. 

Thiruvullakkavu Sree Dharma Sastha   keralawindow.net

Kadavallur Sree Rama temple, Kerala. commons.wikimedia.org

Coming back to  Kerala temples,  the version of  Dravidian architecture found in this state  is significantly different. Large temples with many mantaps (halls) are rare, so are the tall towers at the entrance.  The sloping roofs with projecting eaves in the enclosures dominate the outline, often arranged in a number of tiers, not more than a few with some exception. As in Bengal and NE India, this adaption is a necessity in tune with the geography and heavy monsoon rainfall. However there is  a stone core below a wooden (preferably  timber) superstructure. Introduced during  the Chera dynasty in the 12th century,  there are a variety of ground plans including circular ones. The multi-building complexes came  up relatively late.The architecture of Kerala  is according to Indian Vedic architectural science (Vastu Shastra) and part of Dravidian Architecture, one of the three styles of temples mentioned in the ancient books of Vastu Shastra. The Tantrasamuchaya, Thachu-Shastra, Manushyalaya-Chandrika, and Silparatna are important architectural science and they influence  Kerala's  Architecture style. Among the styles mentioned earlier, the Manushyalaya-Chandrika, a work devoted to Kerala architecture is one such science that has its strong roots in Kerala.

Kerala - rafters and beam below the sloping roof. Pinrest com

Koodalmanikyam Temple, Thrissur Rich carpentry work. Elajtrip NTD India

Kerala: carved pillar supporting the beam and rafters. artnlight.blogspot.com

wooden frame, koothambalam, vaddakkunatha temple.kamit.jp/05_

Koothambalam Irinjalakuda.vaikhari.org

wooden frame, koothambalam, vaddakkunathan temple.kamit.jp/05

The designs  and the common architecture are  different from other states. Up to the basement and partly  the wall above it  are made of  stone (mostly laterite plastered in mud and lime) masonry. Above it stands the teak wood super structure.  Murals are seen on several of these temple walls.  The state has a unique  place in the area of  science of wooden building. The tradtionl  wooden architecture of Kerala consists of not only temples but also old institutions and palaces and even houses.  One may be struck by the  homogeneity and continuity in the traditional architecture  across Kerala , apparently influenced by the age-old culture, religion and  environment.  The craftsmen of this state were highly skilled, innovative  and  quite familiar with the art of dealing with various designs suitable to the places and requirements without deviating from the basic princles and  severe constrains laid down by the rules especially when dealing with temples (as per Agama Sastras) . Though they would give room to flexibility in the design  but they would never compromise on quality.  For dwelling places, etc., they follow the Vatsu Sastras and give importance to socially governed special organization. Many Hindu families and also Muslim have a joint family system and need additional space for more members. In the country side substantial central space is allowed for the interaction between family members within the system as we find in the case of old buildings owned by the Chettar communinity (mostly business people) of  Chettinad  in  Pudukottai/Ramanatha puram districts of Tamil Nadu. These buildings are made of brick and lime mortar with Madras terraced ceilings and unique flooring. 
Enrrance, Koothambalam, TV.Puram, Kerala.thehinduimages.com

Above image: Koothambalam, Vailoppilli Samskirithi Bhavan, Thiruvananthapuram, Kerala, well ventilated sides well protected by roof.

Airy hall & ornate wooden pillar, Koothambalam, Kerala archiestudio.in

The traditional architecture that uses lots of wood is native to Kerala whene the two monsoons, especially the SW monsoon bring in copious rains. The low wooden ceiling with extended sloping  roof  all around the structure is meant  to keep the homes/ buildings cool in summer & retain the heat in winter. The gabled roof and ceiling works are the prime feature of Kerala architectural style.  Most of Kerala buildings appear to  have low height visually, due to over-sloping of roofs This design  is meant to protect walls from rains and direct sun shine. 

The Christian and Muslim communities follow the same pragmatic approach in the construction of churches, mosques, homes, etc not deviating  from the homogeneity  commensurate with the physical environment and basic requirement. Multi-tiered mosques with a gabled roof  in Kozhikode district, etc are very rare even in the Islamic  countries. In the public building and in some temples, the walls are  partially  latticed  with wood all around for air circulation and ventilation in the summer. Most of the Koothambalams - dance theters  just out side  the temple complex  are designed with  good ventilation and acoustics facilities.  Grandeur in style, Koothambalam offers a solemn ambiance for traditional dances of Kerala like Kathakali. The participants  assemble with immense passion and devotion in the Koothambalam during the performance of Kathakali. Besides, the dancers undergo training and preparation  in a well ventilated wooden structure that is quite majestic. The beauty of the Koothambalam made of wooden ceiling is further enhanced by the intricate designs and carvings  that may surprise you.