[] 1 Before 1919
[] 2 From 1919 to 1945
[] 3 From 1946 to 1960
[] 4 From 1961 to 1970
[] 5 From 1971 to 1980
[] 6 From 1981 to 1985
[] 7 From 1986 to 1990
[] 8 From 1991 to 1995
[] 9 From 1996 to 2001

By period of construction we understand:
The period of construction of the building as said, or the period of construction of the main part of the building, meaning the support structure, when different parts of a building correspond to different periods of construction.
The period of reconstruction, for buildings that have undertaken complete transformation.
To collect the correct information you must enlighten yourself about the year or period of construction you must ask the proprietary, the doorman or any of the older residents.
In cases where persons (due to old age) might have some difficulties remembering the exact period of construction ask for comparisons with some milestones (i.e. before or after the 1st world war, etc.)
In cases of persisting doubt decide by using information of similar and next by buildings.

Note: If a reconstruction was undertaken please use that works period as the information and not the original construction period.