You can try and find the planning documents by checking with the Planning Department of Dublin City Council. They may or may not still have them at this stage.
If they have them, you will still need an architect/engineer to certify that the works were done in accordance with same and with Building Bye Laws.
If they don't have them, then you need to go back to the solicitor and explain the difficulty. They will advise you as to the implications and what steps, if any, you can take.
The Transfer Order ( Transfer from Dublin City Council to parents) should be with the Title Deeds. Again, if you cannot locate it, tell the solicitor and they will advise you.
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