The German accountants published on August 8 their draft assurance standard IDW PS 821 for sustainability reports.
In spring 2005 the Institute for Sustainability and IÖW evaluated the relevance of assurance engagements and assurance statements in sustainability reports. In the final report from Clausen and Loew (2005) relevant assurance standards such as ISAE 3000, AA 1000, the Duch Draft NIRVA 3410 and the now published Draft IDW PS 821 are described and compared to each other.

The authors come to several conclusions. E.g. they argue that credibility of a sustainability report can be achieved in different ways so external assurance of a sustainability report can be only one several factors. So external assurance of the sustainability report is not compelling to achieve credibility. On the other hand there are different types of assurance processes, with different benefits for the sustainability performance of the company. Hence credibility is not necessarily the only benefit of assurance engagement and in case a company seeks external verification of its report it is important to select the suitable standard.

* Draft IDW AuS 821: Generally Accepted Assurance Standards for the Audit or Review of Sustainability Reports
*Internationale Analyse des Nutzens von Testaten in der Umwelt- und Nachhaltigkeitsberichterstattung Berli