The house is of the type called Bahay na bato , literally " house of stone " , however , reflecting American colonial influences , the lower storey is not constructed of stone but of concrete . The foundation posts are made out of trunks of the '' balayong '' tree , a local hardwood ; the floorboards are of the same material . The house 's upper storey is constructed of wood topped with a roof of galvanized iron instead of tile ( reflecting the late-19th century trend started in Manila owing to a rule discouraging the use of tiles in favor of then-novel '' hiero '' as roofing material in the aftermath of the 1880 Luzon earthquakes )
1880 Luzon earthquakes
1880 Luzon earthquakes
Balay Negrense