Walus, Konrad

Diploma Thesis:
1960

Topic:
Appropriateness of surcharges for general business costs, risk and profit in construction contracts in accordance with Section 650c BGB

Editor:
Konrad Walus

University Professor Responsible:
Univ.-Prof. Dr.-Ing. Dipl.-Wirt.-Ing. Jens Otto

Supervisor:
University Supervisor: Dr.-Ing. Jan Kortmann

Editing Period:
23.05.2023 until 26.09.2023

Abstract:
In the construction industry, the principle of calculatory price updating for the remuneration of changed and additional services was long considered irrevocable. The introduction of construction contract law into the German Civil Code (BGB) in 2018 introduces a remuneration system with Section 650c (1) BGB that provides for the additional or reduced expenditure to be remunerated according to the actual costs required with appropriate surcharges for general business costs, risk and profit, thus breaking with the established Korbion rule ("Good price remains ..."). According to the prevailing opinion, appropriate surcharges must also be measured against the criterion of factuality. Based on this principle, a calculation standard was proposed in the study that derives the appropriate surcharges from the ratio of contribution margins (difference between the total invoiced and the production costs) to the total invoiced for completed orders. A quantitative survey showed that there is no significant correlation between the contribution margin/settlement total ratio and the industry, company size, company location and the cost structure of the construction project, so that "industry-standard" surcharges can be determined independently of these factors.