Temple architecture of Bengal
Due to the shortage of Stone (in gangetic plains) and specific climatic condition (heavy rainfall etc) , mostly Bengal temples are relatively small in size. These temples are mostly built with Mud/Clay Bricks , Adobe (Sun Dried Brick) , Terracotta & Lime Morter. In some places like Bishnupur , Laterite stones are used.
According to David J. McCutchion, historically the religious architecture in Bengal may be divided into three periods:
Early Hindu period (up to the end of the 12th century, or may be a little later in certain areas)
The Sultanate period (from 14th to early 16th centuries)
Hindu revival period (16th to 19th century)
Early Hindu temple architecture in Bengal
Of all the temples constructed in Bengal before 12-14th century, few have survived. The temple architecture of ancient Bengal can be divided into four basic types:
The Bhadra, pida, or tiered type, in which the roof over the sanctum consists of a series of gradually receding tiered stages crowned by the usual finials including the amalaka. Pirha temples are mostly found in Pashchim (west) and Purba (east) Medinipur. The elevation is relatively low.
The second type, which seems to have been the more predominant type, is the rekha deul form with its tall lofty shikhara over the square sanctum. The rekha deul is what is better known as the nagara architecture in later silpasastras, and of which the Kalinga style is a regional variation. The distinctive features of this type are : cruciform ground plan (square sanctum with offset projections on each face), and a curvilinear tower (sukhanasa sikhara), and this style is seen across entire northern India.
The third group of temples, the tiered type surmounted by a stupa, is known from a Lokanatha temple at Nalendra from a painting in a manuscript, and this style likely was from the tradition which led to the Abeyadana and Patothyama temples at Pagan (Myanmar). Here the roof rises in gradually receding tiers and is surmounted by a fairly large stupa. The corners at each stage are further decorated with miniature replicas of the stupa. No such structural temples now remain in Bengal.
The fourth group of temples, the tiered type surmounted by a sikhara, are best seen in an illustrated shrine of Lokanatha, from the 1015 CE copied version of the Prajnaparamita manuscript (MS. Add. 1643 at Cambridge). Here the roof rising in gradually receding tiers is surmounted by a sikhara, complete with all its component elements. In all the found illustrations it is seen the roof is a sloping one with gradually diminishing stages and curvilinear sikhara placed over the last stage. In the top of section there is the amalaka and the usual finials (a stupa at top if it was a Buddhist temple).
Sarvatobhadra temples: a unique feature of the ancient and early medieval Bengal temple architecture
The sarvatobhadra temples are built on a square, broad jagati or platform, and are surrounded by a wall or prakaras containing smaller shrines. It can be approached from all four sides by stairs that have two smaller shrines on two sides. There is one such smaller shrine at each corner of the square terrace. The main temple lies at the centre of the courtyard, and its square garbhagriha has four mandapas in the four directions with four doors. In the corners of the sanctum are placed four other smaller sanctums and correspondingly four smaller shrines are placed in corners between the mandapas. The central shikhara is the tallest, and dwarfs the others, each with its own sukhanasas, and the shikharas are richly carved with amalasarakas, gavaksas, jalas, and various other motifs. There are tanks spread across the courtyard of the sarvatovadra temples.
The Sultanate period
The coming of the Muslims at the beginning of the 13th century marked a sharp break with the past. But temple building didn't stop entirely. There are temples built by the Malla kings during this period, such as the Shantinatha temple at Sihar by Jagatnatha Malla (1309), Jagannatha temple in Bishnupur by Patit Malla in 1449, Dasabhuja temple in Bishnupur by Chandra Malla in 1529, Gopala temple at Banki and Ekteshvara temple by Bir Malla in 1545.
The Hindu revival period
Architecture of Bengal got it’s own identity after the advent of Shri Chaitanya and revival of Hinduism in 16th Century. Between the earlier Hindu period and later Hindu revival period, Bengal temple architecture saw a major transformation and underwent numerous changes: the worship of Vishnu gave way to that of Radha-Krishna, of Chamunda to that of Kali; Surya fell entirely out of favour; curious folk cults like that of Dharmaraja or Dakshina Raya arose. The earlier tiered form (pirha style) and the tall nagara sikharas (mostly rekha deul styled) almost went out of fashion, and was replaced by the chala and ratna architectural styles.
Chala style temples: Traditional Bengali’s hut roof or the Chala roof is gable type with two-, four- or eight – sloping roofs with curved edges or cornices meeting at a curved ridge. The slope of the roof performs the drainage function against rainfalls. The curved structure is due to flexibility of roofing material i.e, bamboo and thatch used in Bengali hut. The interior curvature of traditional hut roof supported by the bamboo or wooden posts forms a dome. To increase the longevity in high rainfall areas, temples were made of regionally available bricks and terracotta.
The Ratna or Pinnacled styled: In the ratna style, the roof is more or less flat and it has a towering pinnacle known as the ratna (jewel). The number of ratnas can be multiplied by 9, 13. 17, and 21, upto 25 (panchavimshati-ranta).
Flat roofed dalan temple style: With heavy cornices on S curved brackets, they show European influences (Neo Classical Architectural Style to be precise), and became popular in the 19th century for a brief period. These were internally domed, more usually spanned by a shallow vault, and latterly flat ceilinged. Almost always they had a porch with one or more pillars, initially showing the traditional faceted type, but in the 19th century these became the clustered pilaster type. Arches in such style are cusped, and facades were patterned with terracotta designs and later by plasterwork.
Grouped Temple
Temples of identical style and size are sometimes grouped together. Two identical Shiva temples are called a Jora Shiva temple. Groups of four, six and twelve Shiva temples are quite popular. The most elaborate groups existing have 108 Shiva temples.
Links:-
https://www.quora.com/What-are-the-different-types-of-Bengal-Temple-Architecture
https://en.m.wikipedia.org/wiki/Bengal_temple_architecture
https://deccanviews.wordpress.com/category/bengal-temple-architecture/
https://religiousarchitecturebengal.cssscal.org/temple-typology/
https://monidipa.net/2022/12/23/bengal-temples-i-the-early-hindu-period/
https://monidipa.net/2023/04/20/bengal-temples-ii-hindu-revival-period-16th-19th-c-ce/