Having recently tried objecting to my neighbours development, I wasn't successful, however there were over 15 households objecting and every single one was supposedly covered by 'planning conditions ' most of which have been breached 🤦
Things I've learned:
I paid a planning specialist to write my letter - it was about £180 3 years ago and it was crap, very vague and didn't reference the local plan.
Get a local person, ensure where possible to counter the argument against the councils own local plan as well as the national plan.
Make your objection easy to read, use bullet points, as others have said be factual.
Also keep an eye out for updated plans and documents, consider how any changes will or won't help you and don't be afraid to write in again to highlight new issues.
Check the documents are factual, the plans submitted by my neighbours were not to scale and they even tried including my garden hedge within their own planting scheme and placing a restriction on my hedge. Plannings response when I objected was they take the plans submitted on 'good faith'
Consider what isn't in the application - it turns out our neighbor omited LOTS which is technically covered under permitted development. When you combine the huge changes with their application PLUS all the permitted development it's created huge issues for us.
Be specific in your requests. You're fighting to stop but also add limitations IF it goes ahead.
Eg neighbors said the farm access road will be grass matting.
It's now a solid road
The planning conditions/ application didn't specify the material they were to use, so enforcement say nothing can be enforced. Every little thing that might impact you, you want to insist is covered by conditions so they can't sneak in extras or changes.
Be sure to reference the previous complaints, I assume the environmental team were involved? Contact them and make them aware as they should also be responding to the application