Get in control, stay in control.
Typically the as-builts of buildings differ 5-10% compared to their original plans. 10% imprecision could equal the total construction cost of the particular buildings during their lifetime (30-50 years).
Renting out your properties with a surface smaller than the actual size might lead to important financial loss, while you still heat, maintain, paint, clean etc. them based on their real values.
Monitor every change in your building with BIM models at your fingertips. Access the BIM model to identify elements and update it easily on the spot.