The two residential buildings, one in Cairo and another in the town of Qalyoub, 20km north of the capital, collapsed between Sunday evening and Monday morning.
In Cairo's Hada'q al-Quba neighbourhood, a four-storey building that was under a demolition order collapsed, leaving five people dead and three injured.
Four of the dead were from the same family. Police rescued 10 people from the bulding.
A three-storey house in Qalyoub also caved in overnight, killing three people and injuring three, a police official said.
Buildings often collapse in Egypt because of poor maintenance.
Many structures are unauthorised and not built according to regulations or with poor materials.