Legal Updates

Cost estimate exceeded: Unperformed work is not deducted

OGH 6 Ob 90/26t | 29.09.2026

Where a cost estimate is provided without a guarantee, the client must accept unavoidable, minor additional costs. The contractor must notify the client in good time of substantial cost overruns under Section 1170a para 2 of the Austrian General Civil Code. If timely notification is not given, the client may withdraw from the contract under certain conditions.

The Austrian Supreme Court (OGH) has now clarified how a cost overrun must be calculated. Work that was not performed must not be deducted from the original quoted amount. Such a deduction would benefit the client. It would reduce the amount used for comparison, making the cost overrun appear larger.

In the specific case, the original quoted amount for a shell construction was EUR 197,551.09. The actual costs amounted to EUR 213,346.15. This represented a cost overrun of approximately 8%. The OGH found that this overrun was not substantial. In earlier decisions, cost overruns of 14% and 30% had been considered substantial.

For clients, this means that the significance of a cost overrun is assessed based on the original quoted amount. Work that was not performed does not change this basis of calculation.

30. 10월 2026