Probably some combination of fertilizer and welding gas or propane. Big boom but not a lot of "push". Loading everything to the street facing side of the house and above ground could use the walls/rooms to direct the blastwave out of the house towards the street and away from the neighbors house. Also could have loaded everything into the basement (seems like a house like that could have a basement) under the rooms where it would be most likely that somebody would try to enter. Then the entire basement would focus the blastwave up.
Explody things are... weird.
Probably some combination of fertilizer and welding gas or propane. Big boom but not a lot of "push". Loading everything to the street facing side of the house and above ground could use the walls/rooms to direct the blastwave out of the house towards the street and away from the neighbors house. Also could have loaded everything into the basement (seems like a house like that could have a basement) under the rooms where it would be most likely that somebody would try to enter. Then the entire basement would focus the blastwave up.