The work addresses the joint liability of architects, specialized professionals, and contractors for construction defects, based on the decision of the Grand Senate for Civil Matters, BGHZ 43, 227 ff. The breaches of duty by the construction participants that justify the assumption of joint liability are specifically detailed. From this, the impact of joint liability on the warranty claims of the construction participants is discussed, and the question is examined to what extent the client must account for any contributory negligence. Once the fundamental liability in external relations is clarified, the issue arises for the joint debtor claimed by the client regarding the extent to which they can seek compensation from the other construction participants, where numerous liability limitations then lead to the so-called disturbed or limping joint debtor compensation.