If the expert report is accepted (and much as the expert might say he has never lost a case in court there will be many other cases which haven't gone to court) then the company would be admitting a breach of contract and you would be entitled to at least the cost of removal as your house would not be sellable with the conservatory in place. You may also be entitled to some payment for inconvenience. If you want to keep the conservatory, generally the supplier won't be bothered but I would recommend having a "condemned" conservatory on your land and you would be better to have it removed.
Would appear to be although he's not a man of skill in the legal sense. He's a paid expert for one party. The other party could have an expert who takes a different view in terms of the degree of fault, possibility of remedial works etc. It's generally better to agree a joint inspection by an independent expert.
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