What were the main building materials used during the Harappan civilisation?

The most important building material that was used by the Harappans to construct their structures were sun-dried or burnt bricks. These bricks were made in moulds of standardised ratios. Baked bricks were used abundantly in Harappa and Mohenjodaro as well as in other settlements of the civilisation. Apart from bricks, mud mortar and gypsum were also used for building activities. Evidences of the use of mud mortar comes from Harappa. There is also evidences of the use of wood. Wood might have been used for doors and windows.