6 new roof apartments completed After 1.5 years of construction: Completion of converted attic roofs in Prenzlauer Allee. On about 500 m², 6 new apartments, terraces and balconies with views over the rooftops of Berlin have been created. Tags: Attic conversionbuilding permitconstruction managementconversioncost calculationgeneral planninghand overplanningresidential apartmentssite supervision