Dadu/Beijing; Unknown Planner/Architect from Turkestan

I read Kublai Khan by John Man, interesting facts that i gather;

-Planning of Dadu/Beijing actually comes from a Turkestani architect, Ikhtiyar al Din

After Kublai was proclaimed Khagan at his residence in Shangdu on 5 May 1260, he began to organize the country. Zhang Wenqian, who was a friend of Guo and like him was a central government official, was sent by Kublai Khan in 1260 to Daming where unrest had been reported in the local population. Guo accompanied Zhang on his mission. Guo was not only interested in engineering, but he was also an expert astronomer. In particular he was a skilled instrument maker and understood that good astronomical observations depended on expertly made instruments. He now began to construct astronomical instruments, including water clocks for accurate timing and armillary spheres which represent the celestial globe. Turkestani architect Ikhtiyar al-Din (also known as Igder) designed the buildings of the city of Khagan or Khanbalic. [84] The Great Khan also employed many foreign artists to build his new capital. One of them named Arniko from Nepal built the White Pagoda which was the largest structure in Khanbalic/Dadu.