flat roofs

[woodturn]

are flat roofs acceptable to the government planning inspectors on single story extensions where ther are non in the area

[buildersmate]

Hmmm. Let's try and unpick what you mean. If you make a planning application, your application will be processed by development control (the Planning Dept). If your application is rejected you then have a right of appeal to the Planning Inspectorate.
If you mean, will the Planning Dept accept my application for a flat roof, then it depends. If you live in a conservation area, then probably not. If your proposed development looks really ugly, then probably not. Go and ask their informal opinion.
If you mean, my application has been rejected by the Planning Dept because of my flat roof - the Planning Inspectorate reverse that decision, then I can't tell you for sure, but it is pretty unlikely.
What's the big deal with a pitched roof? - looks better, lasts longer and probably adds more value to your house (because flat roofs are generally ugly).

[bushbaby_de]

If its a small single storey extension that doesn't require planning permission then you can do a flat roof. As buildersmate said, your question isn't overly illuminating so maybe if you give more info we can give better answers