Renovation is not always recommended
Renovating old buildings to BEN level is sometimes more interesting than replacing them with new ones. Unless the concrete structure no longer meets current standards. Research into potential energy efficiency should therefore always be combined with a thorough study of the existing situation.
However, unpleasant surprises can never be completely ruled out.
For example, in Proeftuin Kielpark the detailed energy optimisation plan could not be tested against reality. During the stripping of the apartment complex, structural problems were uncovered that were not compatible with a cost-efficient renovation.