(1) If, in the production of the work, an act by the customer is necessary, then the contractor may demand reasonable compensation if the customer, by failing to perform the act, is in default of acceptance.
(2) The amount of compensation is assessed on the one hand on the basis of the duration of the default and the amount of the agreed remuneration, and on the other hand on the basis of the expenses the contractor saves or what the contractor is able to earn from other use of their labour.