Expert opinions in construction disputes: court or private opinion

A building is technically complex. Whether damage stems from a defect, what cause underlies it and how it can be remedied can often only be assessed with structural, structural-engineering or building-physics expertise. The court does not possess this knowledge itself, which is why it calls on an expert.

Typical questions to the expert concern the cause of the defect, the proper route to repair, the level of repair costs and any diminished value. From the answers it follows whether a defect in the legal sense exists at all and which claim of what amount arises. The opinion thus provides the factual basis for the judgment.

Precisely because the opinion is so central, early clarity about its function pays off. Those who know before litigation what the specialist can clarify avoid costly detours and can prepare the preservation of evidence in a targeted way. You will find background on this on our focus page on construction litigation and the preservation of evidence.

In court proceedings the court appoints the expert. The expert owes a duty of neutrality towards the court and does not work for either party. The opinion is a full means of proof: the court may base its decision directly on it, provided it regards the reasoning as cogent and comprehensible.

The appointment takes place either in the main proceedings or beforehand in the independent procedure for the preservation of evidence under sections 384 to 389 ZPO. The latter is permissible where it is to be feared that a means of proof will be lost or its use impeded, for instance because building works cover the defect. The expert then documents the present condition, the causes and the repair costs.

The parties are not at the mercy of the opinion. They can put questions to the expert, request a supplement to the opinion and challenge the result with their own arguments. Where there are concrete doubts about impartiality, a challenge is possible. How the judicial preservation of evidence proceeds in detail is explored in our article on preserving evidence before litigation.

A private opinion is one you commission yourself as a party. You choose the expert, formulate the questions and bear the cost. This gives you speed and control, because you do not depend on appointment by a court and often receive a specialist assessment more quickly.

In proceedings, however, the private opinion does not have the rank of a court opinion. It counts as qualified party submission, that is a particularly well-founded submission, but not as a neutral means of proof. The court generally bases its judgment on the opinion of the expert it has appointed, not directly on the private opinion.

Nevertheless, the value of a private opinion is high. It helps you to assess the prospects of success realistically before litigation, to substantiate the claim towards the contractor and to support the plausibility of your position in the proceedings. A good private opinion can also form the basis for an out-of-court settlement and thus avoid litigation altogether.

The fees of the court-appointed expert are governed by the GebAG, the Fee Entitlement Act. In a construction case this item is frequently the largest single block of costs, because a structural opinion with an on-site inspection, calculations and a written report is demanding. The exact amount depends on the scope of the questions and the effort involved.

The advance on costs for the court opinion is initially borne by the party relying on the evidence, that is as a rule the party invoking the defect. Only at the end of the proceedings does the court decide on the final reimbursement of costs according to success and failure. Whoever wins the case is in principle reimbursed the advanced expert costs, whoever loses bears them.

This burden makes a sober advance calculation important. Particularly with a lower amount in dispute, the expert’s fee may stand in an unfavourable relation to the claim. This often speaks for a settlement. How cost risk and settlement connect is dealt with in our article on the cost risk and settlement in construction litigation.

A court-appointed expert must be impartial. Where there are concrete grounds that the expert is not impartial, for instance because of a business or personal closeness to a party, the expert can be challenged. The court examines the grounds put forward and appoints another person where the doubts are justified.

The challenge must be made promptly and with comprehensible reasons. Mere dissatisfaction with the result does not suffice. Those who wish to shake an unfavourable opinion generally proceed by way of substantive objections, a supplement to the opinion or questions to the expert, rather than by a challenge.

From a lawyer’s perspective it is sensible to raise objections to the person or content early and in a structured way. This keeps the proceedings flexible and allows the court to clarify open questions before it bases its judgment on the opinion.