Single storey rear extension permitted flue height

[bobbidill]

Hi All,

After scouring the internet, I’m still non the wiser.
We have a single storey flat roofed extension overlooking our garden and we would like to install a DEFRA approved multi-fuel burner. The height of the extension is 3m and permitted development states:

• Flues on the rear or side elevation of the building are allowed to a maximum of one metre above the highest part of the roof.

I’m hoping that someone might know if the ‘highest part of the roof’ is the roof of the main house or that of the extension. I ask as the flue needs to be a minimum of 4.5m above the height of the stove. Thanks!

 

[Nakajo]

Presumably, you've seen the accompanying diagram? Nevertheless, these requirements can at times seem a little contradictory and confusing. In these situations, I just ask whoever's appointed as the Buildign Control Officer/Approved Inspector to clarify.

 

[bobbidill]

Thanks Nakajo. Are you referring to the Building Regulations as it’s actually the permitted development regulations I’m not clear about. Thanks again.

 

[wessex101]

I just had a quick look at the technical guide and for Class G (Flues and Chimneys) it simply refers you to the definitions under Class A. Highest part of the roof is therefore defined as follows....."The highest part of the roof of the existing dwelling house will be the height of the ridge line of the main roof (even though there may be other ridge lines at a lower level) or the height of the highest roof where roofs on a building are flat".

I read that as being the height of the main roof but I confess it is not something I have ever dealt with before so hopefully someone cleverer will be along to give a definitive answer.

I suppose the other thing to consider is was the extension permitted development, if not I doubt you could build a perm dev. flue on a non perm dev. extension.

 

[bobbidill]

Thanks Wessex101, that’s what I wasn’t clear about either. Thanks though.

 

[LukeB123]

I have dealt with 1-2 of these over the past couple of years. As I remember, flues on outbuildings or rear extensions were not explicitly covered by permitted development regulations. I think you would normally fall back on the general height of the building as I doubt the legislation was there to approve 5m+ flues from outbuildings / extensions etc. Unfortunately this often means that a LOT of these type of flues will require PP.

 

[tony1851]

Just build it to conform to Building Regs - which is of course a safety issue. Then if Planning come along and say it's not permitted development, either apply for planning permission (in which case they would have to give it unless they want you to have something unsafe) or simply ignore their request for p.p. - they can't enforce something such as this.

 

[bobbidill]

Thanks Tony1851, it will of course be built to confirm to Building Regs. If we retrospectively applied for planning permission should Planning say it's not Permitted Development, then could Planning not simply refuse to grant planning permission and insist we take the flue down via enforcement?

 

[tony1851]

If we retrospectively applied for planning permission should Planning say it's not Permitted Development, then could Planning not simply refuse to grant planning permission and insist we take the flue down via enforcement?

According to policy guidelines, councils are only supposed to initiate enforcement proceedings if it is in the public interest to do so; they should not take action for a 'minor or technical breach where no harm has occured'.
Furthermore, they should not use the threat of enforcement to encourage the householder to make a planning application, where it is clear that the development would receive planning permission.
If you did apply for planning permission, it is unlikely the LPA would refuse something that was necessary to comply with Building Regulations, contravention of which could potentially be dangerous.

 

[bobbidill]

According to policy guidelines, councils are only supposed to initiate enforcement proceedings if it is in the public interest to do so; they should not take action for a 'minor or technical breach where no harm has occured'.
Furthermore, they should not use the threat of enforcement to encourage the householder to make a planning application, where it is clear that the development would receive planning permission.
If you did apply for planning permission, it is unlikely the LPA would refuse something that was necessary to comply with Building Regulations, contravention of which could potentially be dangerous.

tony1851, thanks again. Do you have a view as to what the 'highest part of the roof' mentioned to in Permitted Development refers to? If it's the height of the roof of the main, 3 storey, house and not the height of the single storey extension then we have nothing to concern ourselves with anyway. Thanks again.

 

[tony1851]

There are two appeal cases (in 2009 and 2010) in which it was determined that the chimney must not be higher than 1m above the ridge line of the extension, and one contradictory appeal case in 2012 which determined that it could be up to 1m higher than the ridge of the main roof.
So it could go either way!

 

[bobbidill]

There are two appeal cases (in 2009 and 2010) in which it was determined that the chimney must not be higher than 1m above the ridge line of the extension, and one contradictory appeal case in 2012 which determined that it could be up to 1m higher than the ridge of the main roof.
So it could go either way!

Ah, thanks Tony. Are you able to point me in the direction of these 2 cases please? It sounds like we take the risk and see what happens. If it were you, how would you interpret the PD directions?

 

[lt8480]

They grey area here in the PD rules is a freestanding flue going vertically up through a roof is not "on the rear elevation".

But it doesn't say it has to be fixed to the main wall of the house, just on a rear or side wall and below the highest part of the roof.

I'd interpret this to mean below the highest part of the roof on the entire/main house, and fixed to any side/rear wall is fine. But a freestanding flues through roofs are not okay.

Probably not what they mean but that's what it seems to say.

Usually though they do allow them coming up from flat roofs and freestanding. Probably because the best way of keeping the flue the lowest height is to keep it away from the main house and windows. If they insist it must be on the main rear wall then you could run the flue to the back wall of the main part of the house, and then take it up the wall and all the way up past the main roof by 1m - of course thats likely to be many metres higher and more visually prominent, but if that's what they insist.

You could propose both options under a LDC application, they will then asses both and confirm either or both as acceptable.