Not all building projects require planning approval for them to be acceptable to your local authority, try this link to see if you need planning approval https://www.edinburgh.gov.uk/downloads/file/27026/for-householders.
All local authorities do take central advice from the Scottish Executive who provide guidance on what is and what is not acceptable when it comes to building projects. You should know that the rules on planning development in Scotland are different to England and all building projects should fall within the planning guidelines or be justifiable if they do not. All building projects are different and are dealt with on a project-by-project basis, you should not assume that just because our neighbour has successfully carried out a building project you can do the same. You should remember that everyone lives next to someone else (the general situation) and your building project will have an effect on them in some way. The planning process is there to protect the amenity of everyone.
In the early stages of thinking about your project you should perhaps visit https://www.edinburgh.gov.uk/downloads/download/13430/planning-guidance as this will give you some idea about what you can and cannot do. hLp architecture have completed over 1200 domestic building projects since 2005 and have a wealth of knowledge on what is and is not acceptable to the local authority.