It's not just more expensive one off homes that are prebuilt in Finland - Over 50% of Finnish homes are now built offsite (or more accurately constructed from 'parts' built off site). This includes both single family wooden homes and concrete apartment buildings.
This is probably a result of: 1) Construction companies are larger and are building on multiple plots with the same concrete apartment building or 10-20 identical or similar wooden buildings 2) The Finnish love affair with family lakeside summer cottages has got people used to ordering a building 'off the shelf'
Precast concrete has been used since the 1950s: https://www.elematic.com/learn/what-is-precast-concrete/
This is probably a result of: 1) Construction companies are larger and are building on multiple plots with the same concrete apartment building or 10-20 identical or similar wooden buildings 2) The Finnish love affair with family lakeside summer cottages has got people used to ordering a building 'off the shelf'