We've altered some existing plans for an extension ourselves and so don't have an architect for applying for planning permission. We've had a go at applying through the Planning Portal but we're wondering how technical we need to be. How much detail do they need? For example do I need to say what the name of the brick style is and what do they want in description of the lighting? Is that outdoor lighting? Hope someone can help. The man on the end of the phone in planning isn't very nice and I don't want to ring him again.
You have to remember that the forms cover everything from porches to massive estates so not everything is relevant. Sometimes you can just leave blanks, but sometimes the forms will not show as complete unless answers are put in. For things like bricks, you can put the name/make if known or just put 'to match existing' for an extension. Lighting refers to external lighting so if you're not having any just put 'not applicable', or 'as existing' etc. The Council will need to have enough information to determine whether the proposal will have an adverse effect on the property/local area (as will neighbours), so just bear that in mind.
If there is vital information missing, they wouldn't be able to register the application as valid, so should come back to you in order to register the application. If they can register it, but other details are missing, they may not come back as Councils are so pushed for time in determining applications. If it is just a basic extension, and the plans clearly and accurately show where it is going and what it will look like, and you have given basic details as to the materials used etc, it should be fine.
If you have a copy of the completed application form from your previous application the answers should be pretty much the same (assuming you are only making fairly minor revisions rather than adding a whole new extension) and if you don't have a copy you should be able to view it on your local Council's website under your previous application reference.