Botched construction costs private developers annually several billion euros . In legal disputes involving construction defects , there was last year around 40,000 sentences before local courts or district courts in the first instance. The construction is far from an easy task. The findings of a recent survey : every other German , who built a house in the past five years or purchased a new condo , complaining of massive defects in construction. But the builders and buyers also suffer from the lack of punctuality : Every fifth project is not completed on schedule . Almost one in four home builders or home buyers has therefore contracts terminated and changed the craftsmen. These are the main results of a survey by the consulting firm Porsche Consulting, the possession of the "world". Were interviewed men and women between 25 to 60 years , who from 2010 to 2014 a house built in the five years or bought a new building. The review was conducted representative survey by market research institute Forsa .