Complex sentence: During the period of Angkor, only temples and other religious buildings were constructed of stone, while non-religious buildings such as dwellings were constructed of perishable materials like wood, and as such have not survived.
Split into simpler sentences: During the period of Angkor, only temples and other religious buildings were constructed of stone. Non-religious buildings such as dwellings were constructed of perishable materials such as wood, and as such have not survived.