Obtuse dormer for loft conversions?

[DIYdude82]

Im desperate for an extra bedroom to stop 2 teenage girls arguing. The ridge height of my loft is only 2.05m but I’ve just had a chat with an architect who reckons I can fit an obtuse sloping dormer to create some extra headroom. It would still be technically a flat roof as the angle wouldnt be much over 90 degrees from the ridge. I’ve never seen this done before; does anyone have an experience/comments?

 

[domdee]

You may struggle with planning as youre altering the roof line. may stand out like a sore thumb compared to neighbours. sometimes is a presevation. im only getting that vibe from other threads on here where people have had similar issues - not had experience of it myslef

 

[JP_]

If permitted development rights have not been lifted, you can put side and rear dormers on without a problem (well, people might still complain).
Only if you go higher than the current highest point on the roof do you need planning permission.

How high are your ceilings on the first floor? You will need new floor joists in the loft anyway, so if there is space to lower the existing ceiling (huge messy expensive job!) you can get more head height that way.

 

[DIYdude82]

Was trying to avoid lowering the ceilings downstairs as they’re only 220 and because of the mess! Maybe it’s a conversation I need to have with planning to see what they come back with. Thanks for the feedback

 

[garyo]

Isn't it permitted development to convert to warm roof, so that must imply raising the ridge by 100mm or so?

 

[domdee]

if DIYdude82 wants a flat roof with an angle bigger than 90deg its going to be higher than ridge