We are extending our house (semi detached). Currently we are pebble dashed - render is in terrible state or repair and needs completely redoing. Can we put a flat render on (and so then being different from next door) without planning permission?
The best thing to do is to check with your local council, just in case they have any particular rules.
I live in a terrace and just about every house in the street is different. Some have flat render, some have pebbledash, some have 1970s stone cladding, some have fake bricks drawn into render and some have the actual original brick. It looks quite nice because there is a lot of variation, but that doesn't mean that your council would be fine with it.
Unless you're in a conservation area, or have any specific planning restrictions on their property (Article 4 direction, or planning condition for instance) you are allowed to change the render. I'm presuming you're just meaning flat render, not stone cladding that ouryve doesn't like?