Fashion is to have an old house built the last century and topclass restored. Some houses are also recently built but in old style.
Due to a combination of outstanding growth in wealth the last 25 years and extremely cheap bankloans ( to artificially stimulate growth) most houses have been restored to high levels.
The backside is the financial risk a country carries with a population highly dependent on loans with (historically) extremely low interest rate. The price of houses in Sweden have also increased to internationally very high levels.