Looks like encouraging new construction is part of the package as pointed by a Reddit user here https://www.reddit.com/r/berlin/comments/3871ik/berlin_becomes_

Looks like encouraging new construction is part of the package as pointed by a Reddit user here https://www.reddit.com/r/berlin/comments/3871ik/berlin_becomes_first_german_city_to_make_rent_cap/ https://www.reddit.com/r/berlin/comments/3871ik/berlin_becom... That new constructions are excluded from rent control. Thing is I can't really find this in German media. Only British media seems to write gist of this new regulation, which seems quite odd.