realm (AREA)
noun [C] 
an area of interest or activity 
The differences between the two groups are quite profound, both in the realm of ideology and in the realm of practical policy.
Several other similar stories have entered the public realm, unnoticed and unchecked.
We knew that the music was leading us into new realms of pleasure.
The change in people's attitudes will slowly move from the realm of theory into the sphere of practice.
Some dramatic successes in the realm of foreign policy marked the last six years of his time in office.
The story remains in the realms of fantasy but is presented as an adult dream.

A new building for the school is not within the realms of possibility (=definitely not possible).