Interpretation of General Permitted Development Legislation - Public forum - Planning Advisory Service (PAS)

Class B makes it clear that you cannot exceed the height of the existing roof. Accordingly if you have a flat roof and you wish to replace this with a pitch roof permission is required. This allowance was really designed to allow amendment to existing pitch roof in terms of shape or form for example if you where putting a room in the roof which required alteration to the slope pitch or shape which did not increase the height.

Thank you for your reply. In case I have not been clear enough, the vast majority of my existing roof is pitched. The flat roof is only a small section. The new pitched section would be well below the height of the rest of the existing roof.

You are in a tricky area with this one. My understanding is that if the part of your house with the flat roof is an extension to the original house which would be permitted development under class A and the proposed pitched roof would also be permitted (e.g. if it is single storey, it would be not more than 4 metres in height), then you have a case. Very broadly, Class B relates to loft conversions and Class C to roof windows. Careful that planners may cherry pick inappropriate parts of the legislation. Hence, if you can successfully argue that the works fall under Class A (i.e. you're now 'completing' the extension) this might be the best option. You could then apply for a Lawful Development certificate (with some LAs, these are handled by quite reasonable legal departments and not the 'development control' people). However, if the LA want an argument then there are probably grounds for argument (the permitted development rules aren't straightforward to interpret). If you don't feel able to interpret the legislation, then you'll need to find a planning consultant. As a side issue, you've perhaps realised by now that if you ask a LA planner if you need planning permission then, invariably, the default answer is yes (e.g. the man from Norfolk, who, given the statement above, may want to re-read Class B).

After some weeks of argument I now have confirmation from a planning officer in my LA that according to the letter of the law in the GDPO, planning permission is not required for my roof alteration. There is nothing in the Class B section of the GDPO that indicates the context restrictions referred to above nor is there a need to refer to Class A. The GDPO was intended to remove the need for formal planning permission for simple developments. The apparent desire by planners to over-complicate matters undermines this goal and may be aimed at maximising revenue . The fact that a view expressed by an officer of an LA is not binding on the LA or in law is also unhelpful. I have written to my MP complaining about all this.