Complex sentence: In the 1940s construction had ground to a near-halt as workers, fuel, rubber and transport were pulled away from civilian use for the war effort, but the post-war 1950s would usher in a building boom on a massive scale.
Split into simpler sentences: In the 1940s, most construction ground to a near-halt as workers, fuel, rubber and transport were pulled away from civilian use for the war effort. The post-war 1950s would usher in a building boom on a massive scale.