Three people escaped injury when a suspect device ignited outside their home.
The front door of the property at Cushlawn Park in Tallaght, south Dublin, was damaged in the attack at 3am.
A Garda spokeswoman said the remains of the device have been removed for a technical examination and the scene has been preserved.
Gardai in Tallaght have appealed for information.
In August, the bomb disposal team was called out to the same estate when a viable device, understood to be a pipe bomb, was found outside a house.
It was made safe and transported to a military base for further inspection.