Construction of the Great Mosque of Djenné ordered in Mali.
Construction begins of the Castel del Monte in Apulia, Italy, for Frederick II, Holy Roman Emperor; used by Frederick primarily as a hunting lodge.
c. 1240–1250 – Heddal stave church in Norway built.
1242 – Rebuilding of Peyrepertuse Castle in France to its current form begun.
c.1245 – Rebuilding of Westminster Abbey begun.
1246 – Lakshmi Narasimha Temple, Nuggehalli built in the Hoysala Empire.
Inauguration of St. Mary's Church, Sigtuna, Sweden.
Start of reconstruction of Bassac Abbey.
Approximate start of construction of original Pagoda of Monk Wansong in Beijing.
April 26 – Consecration of Sainte Chapelle, Paris.
August 15 – The foundation stone of Cologne Cathedral in Cologne is laid by Archbishop Konrad von Hochstaden.
1249 – Sadasiva Temple, Nuggehalli built in the Hoysala Empire.
1240s in architecture Wikipedia