This paper examines the handover process in Norwegian construction industry, focusing on commercial buildings. Improving handover processes reduces the number of conflicts, increases user value, improves indoor climate along with securing overall building performance, both in closing construction phases as well as throughout the building lifetime. As little research is found on the subject, a collective project was initiated by the municipality of Trondheim. This case study is limited to a single, environmentally certified, office building in Norway. The paper aims to determine main delay and defect causes. Finally, some countermeasures are identified. A literature review along with a document study was performed. Seven semi-structured, case specific interviews were conducted in addition to a pilot study consisting of three interviews on the same topic. The case respondents are project managers from contractor and client with extensive experience from the Norwegian construction industry. Several causes in contractor-client interfaces were identified. Among the most critical were late changes and decision-making, lacking understanding of limitations and potential in design-build contracts, conflicting interpretation of specification of work along with complex technical installations. Possible countermeasures are found to be strict decision planning, sufficient time buffers, early reconciliation of client expectations together with sufficiently detailed specification of work and significant specialist knowledge in complex technical coordination. This paper investigates a little scrutinized part of Norwegian construction projects in an effort to better commercial building performance and profitability. Future research on multiple construction projects would help confirm or disprove findings and the identified countermeasures. (C) 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.