25 squares of equal size with 9 small domes in each square (totaling to 81 domes) and alternated by 12 flat roofs to cover the roof. The four courtyards provide light and ventilation. The four corners of the mosque are adorned with towers with three protruding gateways, one in the middle of each face, with tapering turrets flanking each gate. The southern gate, with imposing steps at the main entrance, exhibits a combination of arch and trabeated construction. It has an ornamental rectilinear frame. The turrets flanking the southern and northern gates are circular in shape; the articulation on these gives them a three storied appearance. The main gate, which leads to the qibla on the western wall, has a projecting mihrab. Above the vaulted first floor cells, ubiquitous arch windows (carved out of stone guard) with perforated screens or jalis or tracery, known as "Khirkis", are seen on the second floor. However,the foyer in front of the mihrab is not well lighted since light from the latticed windows on the second floor do not penetrate this space. The approach to the roof of the mosque is from the east gate, and the view from the roof leaves a lasting impression of the geometrical design of the Mosque. The mosque's walls are of rubble masonry construction with plastered surface on the outside. The interior walls are bland but provided with traditional carved stone screens. The symmetrically designed admirable mosque is considered one of “the finest architectural compositions of the Sultanate history.” It was considered Firuz Shah's architectural benefaction. The importance of the Khirki Mosque's architectural elegance has been considered a precursor to the intensely metaphorical Mughal architecture (1526-1857), with the Lodhi period's (1451–1526) architecture – the Delhi Sultanate's last dynasty – marking the transition. Restoration Over the years, a few domes on the north–east side of the mosque have collapsed and a few walls are in a dilapidated condition. The roof is on the verge of collapse at many places. Delhi chapter of Indian National Trust for Art and Cultural Heritage (INTACH) has categorized the monument as "Grade A" in terms of archeological value. It is one of the 43 monuments identified by the Archaeological Survey of India (ASI) for restoration before the 2010 Commonwealth Games. Some conservation works have been initiated by ASI inside the mosque. Heritage experts of Delhi were concerned by the status of the restoration works