In December 1994, Carillion Alawi was awarded the construction of the Sultan Qaboos Grand Mosque in the Muscat area for the Diwan of Royal Court.

The Sultan Qaboos Grand Mosque is one of the flagship developments in the Sultanate. It serves as a place of worship and an Islamic centre through its Islamic Institution Centre.

The mosque’s total capacity is 20,000 worshipers, and it covers an estimated area of 416,000 square metres. The main square-shaped prayer room can accommodate 6,500 worshipers and has a central dome that rises 50 metres above the floor. The mosque’s distinctive minaret lends to its style. Connecting the top of the mosque’s walls and the internal courtyard is a bar inscribed with verses from the Koran in Thuluth script, with Islamic geometric frameworks filling the corridor archways.

The mosque comprises a main prayer hall, inner and outer sahns, the main minaret, four riwaq towers, north and south riwaq halls, and ablution facilities. The central prayer hall dome is at the height of 45m above ground level, and the main minaret reaches up to 92m.

The project also included imported stone cladding, marble, and other high-quality finishing. There was also extensive external landscaping.