Simultaneous new roof and loft extension

[Prodigy]

The permitted development rules on altering an existing roof seem quite clear and easy to understand.

What about ripping off the whole roof though, and then subsequently building a different design to incorporate habitable rooms in the loft space where none previously existed? It begins to be a bit unclear to me. For example:

1. On the one hand, it could be argued that in the first place I can't do it at all because Class B is for "the enlargement of a dwellinghouse consisting of an addition or alteration to its roof" and Class C is for "any other alteration to the roof of a dwellinghouse" - it could be said that building a new roof from scratch comes under neither of those.

On the other hand though, the planningportal.co.uk site says "you do not normally need to apply for planning permission to re-roof your house or to insert roof lights or skylights as the permitted development rules allow for roof alterations subject to the following limits and conditions.

• Any alteration to project no more than 150 millimetres from the existing roof plane.
• No alteration to be higher than the highest part of the roof.
• Side facing windows to be obscure-glazed; any opening to be 1.7m above the floor.

These are specific to "any other alteration to the roof of a dwellinghouse" as detailed in Schedule 2, Part 1, Class C of the The Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended).

There are different rules for "the enlargement of a dwellinghouse consisting of an addition or alteration to its roof" (Schedule 2, Part 1, Class B) which are detailed in our 'Loft Conversion' section."

2. The above seems to be a clear indication that the government regards a new roof as definitely falling under permitted development, via Class C but not Class B, which in turn would suggest that I can build a new roof after all, but that I should entirely ignore Class B and focus on complying just with Class C. That would be a massive problem however, as then no part of the roof could protrude more than 0.15m beyond the planes of the slopes of the original roof...which means effectively all I can do is replace like for like/not enlarge the roof in any direction eg: replace my hips for gables, put dormers in at the back etc.

In theory I'm doing the new roof and enlargement at the same time, so in theory I could apply Class C and Class B together, but technically I'm first re-roofing and then afterwards creating the habitable loft space...so is there a chance I could be subjected to enforcement action whilst re-roofing if I rely on this/don't go for householders planning permission?

 

[Leofric]

Well, you will need Building Regulations approval for converting a loft to a habitable room.

 

[Prodigy]

This topic is about planning.

 

[Leofric]

Will leave you to sort it out then.

 

[Prodigy]

Thanks, although if you have an opinion on this planning topic I'd be grateful to see it. Sorry if my reply seemed abrupt; I just didn't want this going off on a tangent.

 

[Leofric]

Ok, fair enough. I had just been reading about another 'loft conversion' on here that didn't comply with bldg. regs so was in that mode.

 

[tony1851]

Your proposal would be considered under Part B rather than Part C.

On the Planning Jungle website, there are a considerable number of appeal cases which deal with this very issue.
Unfortunately, while some would allow what you propose, others would not - seems to be about 50-50.

Interestingly, the legislation itself does not give any proportional limit as to how much of the roof could be enlarged, so
some appeal inspectors say that it's a matter of 'fact and degree', which really means it's too subjective.

 

[Leofric]

So does that mean you are just going to apply for planning permission for what you actually want to do ?

 

[Prodigy]

So does that mean you are just going to apply for planning permission for what you actually want to do ?

I'm working on a list of all the pros and cons, so I can weigh it up and decide. It's the sort of thing I imagine more people than not would do without an application, and are likely not to have a problem, but my luck so far with planning departments and neighbours who don't live & let live is making me hesitant...

 

[Leofric]

I might have misunderstood but I thought you said - 'That would be a massive problem however, as then no part of the roof could protrude more than 0.15m beyond the planes of the slopes of the original roof...which means effectively all I can do is replace like for like/not enlarge the roof in any direction eg: replace my hips for gables, put dormers in at the back etc.' , which meant you accepted that what you wanted to do was not permitted development and therefore required planning permission i.e. you would need to submit a planning application.
House extensions aren't usually that complicated, an architectural professional would have a fair idea whether your proposals would receive planning permission (unless you are proposing something outrageous !)