L Shape Dormer Conversion - Building regs or Planning Permission

[chris101]

Under building regs for a terraced property, my understanding is that we can only have a maximum of 40m3 for our dormer extension.

Our has has a long rear roof of around 8m in length and 3.5 meters in width.
Is there anyway we could get this approved under PP?
Our neighbour immediately to my right has a dormer conversion and although not exceeding 40m3, they would have no objections and support the idea (as they do not live there now and have rented out the rooms).
The rear of the property has fields so no neighbours would have any visibility looking straight at the dormer.

We have had a few experienced building companies (FMB regulated) round and they said PP regardless of factors in our favour, would still refuse us as a blanket rule and we should take the risk through Building regs (we would need to sign a disclaimer for the builders).

What do you guys recon I should do?

 

[tony1851]

Are you sure you are over the 40m3 limit? (It's the additional volume not including the pre-existing volume in the roof void).

 

[chris101]

I am not sure but I am assuming the company who has given as some plans have used most of the 40m3.
Please see attached pic.

Ideally we want a bigger separate bathroom and rear dormer (we don't want to reduce the size of the front dormer by having the bathroom within it).

We was thinking of adding 2 more meters of length to the rear dormer but not sure if that will exceed the limit?

 

[Nakajo]

Oh - a terraced house

 

[tony1851]

If you want to get it done under Permitted Development, you will have to keep the volume of the dormer
below 40m^3. If it is local planning policy to refuse dormers, that is the only realistic way to get it, even if it means reducing the size a little.

 

[chris101]

What are the reasons that anything above 40m3 is rejected?
One builder advised he would be happy to extend beyond the amount but I would need to sign a disclaimer.

Doesn't make no sense to me why certain rules that make no sense have to be applied.
Especially rules about the wrap around extension where you require a small gap to exceed more than 3m for the side extension....

 

[tony1851]

have you got any proper drawings to show the dormer? - without those it's difficult to give any pointers.

 

[chris101]

Only this other one.
Screen Shot 2015-11-08 at 20.58.07.png

We haven't had official drawings drawn up yet as we want to know what are options are first and then plan accordingly.

 

[Nakajo]

So it does look like you've incorporated the existing volume into your calculation. Is that right?

 

[chris101]

For the side dormer I think he hasn't but for the rear dormer I am not to sure?

 

[tony1851]

Still hard to tell - might be about right for the rear-facing dormer, but not sure on the outrigger dormer. It depends on how high the
ridge is on the outrigger, which we can't see.

 

[chris101]

2.1m if you mean the highest point for the rear dormer