The scope of "permitted development"?

[BlueJohn]

I've applied for a certificate of lawful use for a ground floor extension which, after reading up on the guidance, I believe is within our permitted development rights.

Because I'm assuming it will be within our rights, I've not given much thought to the exact design, and showed it on the sketches as having a simple pitched roof. I also showed these to the neighbours prior to applying for the certificate and they initially indicated they thought it was fine. One of them has now raised a concern about the height of the roof on their side, so I said I'd be happy to modify the design to lower it (eg by having a "salt box" gabled roof with a shallow pitch on their side).

It now occurs to me that perhaps I should have represented this design on the sketches, but am I right in thinking that as long as the structure is within permitted rights (volume, height, distance from roads, etc.), it can be designed however I want?

The planning officer came round today to do some measurements of our existing lean-to shed and other things but didn't say much. I mentioned that we thought we might modify the roof design from those shown in the sketched, but he just said they could only assess what's before them, which is fair enough.

Does anyone have any experience with this? Will a modification like this after obtaining a lawful use certificate get me into trouble?

[sm_jamieson]

I "decided" my planned extension was within permitted development, and therefore does not need planning permission. I asked the council about lawful development etc, and they denied there is any such thing, so I just got on with it (plans for building control etc).

If it is within permitted development rights, you do not need planning permission. It appears you can build it how you want, so long as it is safe and complies with building regulations. Permitted development is subject to certain design restrictions, but in theory you could still build a monstrosity.

What's the planning officer for ? Are you doing other works that are not under permitted development ? I was advised against mixing the two - apparently the council will get "confused".

What is the legality of a "lawful use certificate" anyone ? As I said, I could not get one. They said I would have to apply for planning permission to find out if I needed planning permission. So I just got on with it, based on their planning guidelines.

Simon.

[BlueJohn]

Interesting. I called the planning office (London Barnet), who said if I thought it was within the permitted development, I could if I wanted to apply for a certificate of lawful use (an S192 - which is half the price of applying for planning permission). This is because a) some builders may not like doing the work without it, and b) house buyers will probably want evidence that the work was lawful. They said legally there was no difference between a planning certificate and a lawful use one, and that most people only used planning permission if they wanted to go beyond their permitted development rights.

All I'm doing is an extension. My assumption is that he was only there out of due diligence and to make sure I wasn't covering something up like a huge shed in the garden - which would count against my development rights. He measured my little tiny shed (which I mentioned on the application) just to make sure.

My understanding is that you don't need it if you think you're within your rights, but it's wise to get a certificate of lawful use to make sure. You can get the lawful use certificate retrospectively too, by the way. I filled in a "proposed use" version - there is an "existing use" one as well:

this is something that's location dependent, but I'm surprised you were told it didn't exist!

BJ