Before a builder-owner can claim damages from his architect in the case of construction defects due to a supervision error, he must first claim supplementary performance from the construction company carrying out the construction due to the subsequent execution error.
Right to refuse performance
Section 650t BGB provides architects with a right to refuse performance if the client/ordering party has not yet unsuccessfully set the building contractor a reasonable deadline for subsequent performance (Sections 634 No. 1, 635 BGB). Conversely, the architect therefore does not have a right to refuse performance pursuant to § 650t BGB if the building contractor rightly refuses to remedy the defect and does not have to remedy the defect.
However, architects are not automatically liable in a subsidiary manner vis-a-vis the company carrying out the construction; rather, they must actively invoke their right to refuse performance and may only be able to refuse to pay damages initially.
Only in case of monitoring errors
This right to refuse performance only applies in the case of a monitoring error; not in the case of planning errors. In the event of a planning error, there is still the possibility of joint and several liability. However, if an architect/engineer has made both a supervision error and a planning error, the above-mentioned right to refuse performance is also ruled out because the client/ordering party will primarily assert claims against the architect due to a planning error ("the planning was defective from the start").
In summary, architects can invoke a right to refuse performance against the client if the latter claims damages against them. For this purpose, the building must have a defect that is attributable to a monitoring error on the part of the architect. The right to refuse performance does not apply if the construction defect is at least also due to a planning error on the part of the architect subject to supervision. The architect's right to refuse performance shall cease to apply as soon as the customer has set the executing construction company an unsuccessful period for subsequent performance, i.e. the contractor has not remedied the defect within a reasonable period or has not remedied it completely. An owner/buyer does not have to file a defect claim against the contractor beforehand.
Author: Lawyer Dennis Wiegard
Dusseldorf, July 2023, 13th