Hello, my name is***** am a qualified lawyer and I will be assisting you with your question today.
I replied on the other question with the steps. A surveyor is not mandatory at this stage and what could happen is if the court wants further evidence they could instruct that you appoint a surveyor jointly with the other side, so someone you are both happy with rather than someone you choose yourself which could be seen as somewhat biased. If he decides to bring a solicitor then you should not have to bring one yourself unless you want to and even if you lose you would not have to pay their fees.
Hope this clarifies?
You are welcome