As an expert witness, by virtue of education, training, skill, and experience, we are believed to have knowledge in the subject of Building Envelopes beyond that of the average person, sufficient that others may officially (and legally) rely upon our specialized (scientific, technical or other) opinion. This opinion about an evidence or fact issue within the scope of our expertise, referred to as the expert opinion, is regarded as an assistance to the fact-finder. We may also deliver expert evidence about facts from the domain of our expertise.
Typically, we are relied on by both sides of a dispute for opinions on severity and culpability of failure and the like.
We may be hired as an expert to help evaluate the case. This kind of expert opinion will be protected from discovery. If the expert finds something that is against its client, the opposite party will not know it. This privilege is similar to the work product protected by the attorney/client privilege.
If the witness needs to testify in court, the privilege (protection from discovery) is no longer protected. Our identity and nearly all documents used to prepare the testimony will become discoverable. Usually an experienced lawyer will advise the expert not to take notes on documents because all of the notes will be available to the other party.