The Sarada temple was originally a humble wooden structure with a thatched-roof. During the time of Swami Bharati Tirtha (I) and Swami Vidyaranya, a golden image of the Goddess was installed, and a tiled roof was added to the temple. In 1907, Sri Sacchidananda Sivabhinava Narasimha Bharati Mahaswamigal decided to erect a more elaborate temple. The construction was completed during the time of Sri Chandrasekhara Bharati Mahaswamigal and the Kumbhabhishekam was celebrated in 1916.
The Saradamba temple is constructed in the modern Dravidian style, with a gopuram at the entrance, and broad covered walkways for pradakshina. The beautiful image of the Goddess can be seen from the distance as one enters the temple from the main gopuram. She is seated on the Meru of the Sriyantra, on a golden throne, inside the garbha-griha, which is made of polished granite. In front of Her sanctum is a spacious hall supported by pillars with exquisite carvings on them.
Within the temple of Saradamba is kept the Vyakhyana Simhasanam, which represents the sarvajna-pitha, the throne of transcendental wisdom. The Acharyas ascend this simhasanam when they are first initiated into sannyasa, when they take charge at the matha, and also on ceremonial occasions like the nine days of the Navaratri festival.
In the advaita tradition in particular, and Hinduism in general, Brahman is worshipped both as the God and as the Goddess, and both with human form and without. Brahman is not limited by gender or form. Saguna Brahman can be equally He or She, because Brahman is beyond such human characterization.
That is why Sri Sarada reigns alone in Sringeri. In temples which are organized according to the Agamas, the Devi is usually worshipped along with the Svami, Her Divine Consort. But Saradamba, as worshipped by Adi Sankaracharya himself, includes all the Devatas and transcends them. In the Prapancasara, Adi Sankaracharya describes Goddess Sarada as Brahmavidya, which is identical to the Incommensurable Brahman Itself. As Brahman, She encompasses the Trimurtis, Siva, Vishnu and Brahma and their Saktis, respectively known as Uma, Lakshmi and Sarasvati. This is brought out well in the various Slokas composed in Her honor, by the Sringeri Acharyas over the ages. She is sometimes addressed as Sarasvati, sometimes as Isvari, or as Sri, and at other times, even the specific attributes of the Trimurtis are attributed to Her. The idea is that She is identical to the essentially formless Brahman, and therefore is the basis of all these specific forms.