Hi Rebecca
We had a similar situation last year and I got lots of good advice here.
I think if you do not want the estate to be built, you should voice your opinon by way of submission to the county council ... not that they pay much heed.
If you think the estate is in contravention of the county development plan, which you can get online from the council website you should definately take it further.
I would not get personal about it, nor would I enter into any discussions with the land owner etc. about it, if it were me. I would simply use my right to object if I wanted to do so and see what happens.
Be very clear in your own mind what you would be happy with ... worst case scenario would a 1.8m wall keep you happy?
Go to the planning office and request to see the file. Make sure you see the whole file ... it's not uncommon for this particular county council to omit half of the pertinant infomation!
An estate per say may not be a bad thing ... it just depends on what they are planning to build. If there isn't a good mix of house types, you will get all the same type of buyers ... ie first time buyers or young families ... who will have children all around the same age ... which will grow up to be teenagers at the same time ... well you get the jist
I will PM you with our own planning case to give you an idea of what is involved.
Good luck.