If I might be so bold as to add my twopennorth:
The 2008 amendment to General Permitted Development Order is a total mess. We warned the Communities and Local Government department about this when the draft Order was published for consultation last year. It should come as no surprise that despite all of the warnings from local planning authorities, the Government enacted the new Order without taking any of the warnings on board.
Now that I've finished my rant, I'll let you into a little secret: us planning officers don't know the definitive answer to the question either.
First up, I am assuming that neither Wall A nor Wall B has previously been extended. If they have been extended, you're into a whole new ball game.
In the scenario that you want to extend wall B by 3m and then build straight across the full width of the plot, you'll require planning permission. That's beyond dispute.
In the scenario that you want to build A+3 and B+3, the logical way of reading the 2008 Order is that it would be permitted development, especially if both walls are part of the original rear elevation.
However, some authorities (mine included) take the view that it's 3m from main rear elevation only, and in your instance the main rear elevation is Wall A. I happen to disagree fundamentally. But I know the Director of my department sought for clarification on the issue from the Communities Secretary and got nowhere. Instead, he sought the views of fellow directors in other London Boroughs. Basically, they all have different views.
The simple fact is that we're all waiting for someone who has an application for an A+3 and B+3 lawful development certificate refused to then appeal to the Planning Inspectorate.
I know, I know. It's crazy. And I'm rather ashamed to be a part of it.
The 2008 amendment to General Permitted Development Order is a total mess. We warned the Communities and Local Government department about this when the draft Order was published for consultation last year. It should come as no surprise that despite all of the warnings from local planning authorities, the Government enacted the new Order without taking any of the warnings on board.
Now that I've finished my rant, I'll let you into a little secret: us planning officers don't know the definitive answer to the question either.
First up, I am assuming that neither Wall A nor Wall B has previously been extended. If they have been extended, you're into a whole new ball game.
In the scenario that you want to extend wall B by 3m and then build straight across the full width of the plot, you'll require planning permission. That's beyond dispute.
In the scenario that you want to build A+3 and B+3, the logical way of reading the 2008 Order is that it would be permitted development, especially if both walls are part of the original rear elevation.
However, some authorities (mine included) take the view that it's 3m from main rear elevation only, and in your instance the main rear elevation is Wall A. I happen to disagree fundamentally. But I know the Director of my department sought for clarification on the issue from the Communities Secretary and got nowhere. Instead, he sought the views of fellow directors in other London Boroughs. Basically, they all have different views.
The simple fact is that we're all waiting for someone who has an application for an A+3 and B+3 lawful development certificate refused to then appeal to the Planning Inspectorate.
I know, I know. It's crazy. And I'm rather ashamed to be a part of it.