Compliance submission letter

We have just received planning permission and there were 10 conditions attached. 3 of the conditions are unrealistic and the planning dept told me to write a letter under compliance submission - has anyone done this and do you think it is successful or should I hire an architect/engineer to write it for me?

What does "write a letter under compliance submission" mean? Did the planning department tell you?

What is it about the conditions that are unrealistic?

Ella,
can you ask your architect has he/she done it before?
We are applying for PP soon hopefully; it'll be interesting so hear what the unrelaistic conditions are.