。
Wooden houses burn more easily than stone ones.
Literal
Wood-built [possessive-の] house [topic-は] stone-built [possessive-の] house [than-よりも] burn-easy.
よりも is the comparison particle より ('more than') with emphatic も attached — slightly more emphatic than bare より. The pattern X は Y よりも Z is the standard 'X is more Z than Y.' 石造 mirrors 木造: 石 ('stone') + 造 ('built'). A nice minimal contrast between two compound construction terms.