Height of raised party wall on dormer loft

[Billthebuildernot]

Hello,

Sorry for asking this question, but I have immersed myself in so many P.D rules I have forgotten what I know and don't know!

Raising the party parapet wall for a dormer loft extension - does the raised parapet wall have to be kept below the ridgeline of the existing roof (taken to be the top of the rounded cap - got this bit from planning jungle!) or can it just be run horizontal from the top point of the existing parapet wall (so 200mm or so above the ridgeline)

 

[Billthebuildernot]

ps spoke to the planning officer who said that it was his view of reading the class B1 rules that the height of any part of the extension (so including the raised party wall) cannot be above the height of the existing roof (which excludes the chimney and parapet) and so the parapet must be brought down to ridge height at the back.

Would love to hear opposing views to this!! (he did say if I had a different view of this then I would just need to state why in the CLD application)

 

[jamesr36]

I agree. No part of the extension should be above the top of the ridge. Another point to consider is that all work must be contained within your own boundaries so by raising the party wall half of the wall you are extending is next door.

 

[^woody^]

I can't understand why you would need to raise a new parapet higher than a new dormer roof?

 

[jeds]

Non-starter I think. All appeals I have seen confirm that the highest part of the roof is the ridge line and parapets (and chimneys) are not counted. No part of the new extension can extend above the highest part of the roof (i.e. the ridge line) and therefore raising the parapet as you propose is not permitted development.

 

[Billthebuildernot]

James - It is accepted that raising of party walls can be considered within your own boundary so it is within permitted development.

Woody - no need as such (other than than ceiling joist at the rear of the property goes into the wall, so the wall needs to be higher than this to enclose the joist - sorry not a technical description, just as I saw it). As the roof does slope slightly downwards, I'm sure its still fine.

My question was because the builder had taken the parapet up to the top point of the original parapet wall (as this was what I had planning permission for with a mansard extension). He's lowered it now anyway so no problem!

Jeds - thanks, we lowered it as we want it within PD (hence question)