Excavations at the Harappan site of Rakhigarhi have unearthed a specialized building that archaeologists are calling an 'Architecture Bureau.' The structure contained a collection of unprecedented clay scale models depicting multi-story residential blocks, complete with miniature doorways, drainage chutes, and internal staircases. These models suggest that Indus Valley urban planners used three-dimensional prototypes to design their highly standardized cities before construction began.
Along with the models, researchers found etched copper plates that may have served as architectural blueprints or land-deed records. The presence of such a facility confirms that the grid-based layouts and sophisticated sanitation systems of the Indus Valley were the result of rigorous professional planning. This find provides the first direct evidence of the 'design phase' in ancient urban history.