Permitted planning and loft conversion

[indus]

Hello

I have a semi detached house. I already have a certificate of lawfulness for a proposed (not built) loft conversion that is below 50m3 increased volume.

I'm now also thinking about doing a second floor rear extension (ie above a single storey part of the house) under PD. Now if I were to do this first I would obviously increase the roof volume as a result of this extension.

Would this increase be then subtracted from the 50m3 I would be allowed for the loft conversion. Or could I carry on and make a loft conversion of the full 50m3 despite the fact that I've done the 2nd floor extension?

Thanks

 

[DevilDamo]

Firstly, you mean a 1st floor rear extension

Secondly... What would this "extended" roof be used for... storage or usable floor space (i.e. loft room)?

 

[indus]

Firstly, you mean a 1st floor rear extension

Secondly... What would this "extended" roof be used for... storage or usable floor space (i.e. loft room)?

Yes, I do mean 1st floor extension

Not sure what you mean by your question, maybe my question isn't clear.

If I did the 1st floor rear extension it would naturally require a roof that matched the existing. Therefore the existing roof space would be increased. I wouldn't use it for anything at this point, its just a normal uninhabitable loft space. However straight after I want to do the loft extension (bedrooms).
I am allowed to increase the roof volume by 50m3 for a loft under PD rules, however when I did the rear extension I would have already increased the roof volume as explained.
Therefore, does the volume I've increased the roof space by when I did the first floor extension get subtracted from my 50m3 allowance when I do the loft?

Thanks

 

[jeds]

The volume limit is a toal for all extensions etc. If you add a rear extension which adds volume to the roof you will reduce your loft limit. The certificate of lawfulness is irrelevant.

 

[DevilDamo]

If you add a rear extension which adds volume to the roof you will reduce your loft limit.

I disagree. The 50 cu.m allowance is to convert a loft (to habitable space). Why would that figure be used in creating a traditional roof, which will be used for storage? If they wanted to convert that roof to habitable space, then yes. But extensions under PD are classed differently to loft conversions.

 

[indus]

Thanks to DD and Jeds for replying.

Two differing opinions here, anybody in a position to give a definitive answer?

Thanks again

 

[freddiemercurystwin]

You may be able to get a definitive answer from your local Planning Department. I would advise you to ring them rather than email them, emailing Local authority's is seldom successful. As demonstrated already in your thread, the rules are not particularly clear (as is extremely common for the Permitted development rules).

My own take on it is that the allowance is only for lofts and other additional can be ignored. Sorry but the rules as they are currently written suck! http://www.planningportal.gov.uk/uploads/miniguides/loft/loft_conversion.html (page 2 in particular)

 

[DevilDamo]

There is reasoning behind my opinion.

You could build an extension of a certain size and it be classed as PD. If you then put a roof (for storage) on it, which is larger than the PD allowances (i.e. 50 cu.m), then does that mean you would have to apply for planning... no you wouldn't?

However, if you were to introduce a large roof, that would be stipulated within the PD guidelines for extensions... nothing to do with loft conversions.

 

[indus]

I spoke to the duty planning officer today and she seemed to think that the volume of the roof of the 1st floor extension would indeed be subtracted from my 50m3 allowance if I later came to do a loft conversion.

I must say though I'm still unconvinced and my gut feeling (and logic) lies with the opinions of Devil and Freddy. The duty officer didn't sound too bright to me!

I will ring again in a few days time and see whether I get the same interpretation of the rules from a different officer.

Thanks again

 

[DevilDamo]

The Planning Officer is correct!

What I said was... if you're proposing a loft conversion to one part of the (existing) building but then proposing an extension to another part of the building, the volume of that roof will not count towards the 50 cu.m limit under PD.

If however, you propose to convert the loft to the new extension then yes, that will be subtracted from the figures already used in the other conversion.

If you don't understand that as I know some wouldn't, I'll summarise...

Extension - Volume of roof not counted towards roof volume limit (i.e. 50 cu.m).

Loft conversion - Volume of 50 cu.m used and subtracted from each time a loft conversion is carried out.

 

[indus]

The Planning Officer is correct!

What I said was... if you're proposing a loft conversion to one part of the (existing) building but then proposing an extension to another part of the building, the volume of that roof will not count towards the 50 cu.m limit under PD.

If however, you propose to convert the loft to the new extension then yes, that will be subtracted from the figures already used in the other conversion.

If you don't understand that as I know some wouldn't, I'll summarise...

Extension - Volume of roof not counted towards roof volume limit (i.e. 50 cu.m).

Loft conversion - Volume of 50 cu.m used and subtracted from each time a loft conversion is carried out.

Sorry buddy but I'm still confused with regards to my own particular circumstances. May I try and explain exactly what I'm planning to do again?

1) First a rear 1st floor extension. This will have a roof that matches the orginal, ie not flat. It will obviously have a volume which will add to the existing volume of my 100% unconverted loft space. All of the loft space at this stage is unconverted, both the original and the new part.

2) I will now carry out a loft conversion. This will be a conversion of the entire loft space (ie orginal + that space added by way of extension in 1)

So, at this point can I still increase my loft space by another 50m3?

Sorry if I'm being dense

 

[jeds]

The PD rules allow you to increase your overall roof volume by a maximum of 50m³. (or 40 for a terraced house) You could build one dormer of 50m³, or you could build two at 25m³ each. Or you could build two dormers at 20m³ each and a clock tower at 10m³.

But you can't build it all.

The PD rules say that the resulting roof space must not be increased by more than 50m³. It specifically clarifies that 'resulting roof space' takes account of ANY increase to the roof space whether it's one extension or the accumalative total of several.

 

[DevilDamo]

If a roof space it is to be used for anything else but storage (i.e. habitable room) then the roof space will be considered under the PD allowances (i.e. 40/50 cu.m).

If a roof space is to be used for storage purposes only, then the roof space will not be considered under the PD allowances (as mentioned above).

 

[jeds]

Where do you get that from?

The rules say:

B.1 (c) Development is not permitted by Class B if—

the cubic content of the resulting roof space would exceed the cubic content of the
original roof space by more than—
(i) 40 cubic metres in the case of a terrace house, or
(ii) 50 cubic metres in any other case;

B.3 then goes on to say:

For the purposes of Class B “resulting roof space” means the roof space as enlarged, taking into account any enlargement to the original roof space, whether permitted by this Class or not.

So that means any enlargement must be accounted for whether by permitted development or by some other development.

I'm also not aware that PD rules mentions habitable space or storage space. It just talks about volumes.

 

[DevilDamo]

I think we may be getting our wires crossed.

If you're building an extension with a pitched roof, which falls within the PD guidelines, then it's considered to be PD.

If you're building an extension, also with pitched roof but the volume of that roof exceeds the volume allowances, you're implying a planning application would be required?

I'm saying the volume allowances relate to converting a roof space (i.e. loft conversion).