Do I need to make a planning application?

[napoleondynamite]

The frustrating thing about this is that any house with even a small original outrigger /extension on the back and which is less than one-half the width of the house, cannot have a rear extension under PD.

The purposes of the various restrictions are often not explained. I imagine there was a concern about extending off the main side walls of a dwelling, but to be fair it would probably be a bit tricky to come up with wording to cover just that, given the varying nature of dwelling designs and footprints. So we are stuck with the arbitrary restriction of no more than 1/2 the width when any side wall is involved. Which does have some somewhat harsh consequences in some cases.

 

[oculushut]

Not sure whether this has been spelt out so--

The rear-most extension will need Prior Approval or planning permission as the combined depth of 6m applies.

The 'infill' extension will need planning permission if its width is more than 1/2 that of the main house.


See the relevant Government guidance here

See p18, The example diagram shows your situation.-

Where a new extension is joined to an existing extension, under paragraph (ja) (see page 29) the limits in (f) apply to the size of the total enlargement (being the proposed enlargement together with the existing enlargement). The following example, showing a side view of a detached house, would not be permitted development. If a detached house has an existing, single storey, ground floor extension that was not part of the original house, and which extended beyond the rear wall by 3 metres, then it would not be possible to add an additional single storey, ground floor extension of 3 metres without an application for planning permission - because the enlarged part of the house would then extend beyond a rear wall by more than 4 metres.




The side wall / side extension issue is dealt with at p23, again with diagrams to assist-

(j) the enlarged part of the dwellinghouse would extend beyond a wall forming a side elevation of the original dwellinghouse, and would –
(i) exceed 4 metres in height,
(ii) have more than a single storey, or
(iii) have a width greater than half the width of the original dwellinghouse

A wall forming a side elevation of a house will be any wall that cannot be identified as being a front wall or a rear wall. Houses will often have more than two side elevation walls.

Where an extension is beyond any side wall, the restrictions in (j) will apply. Any extension can only be a single storey, must be less than 4 metres in height and can only These are all walls forming a side elevation This is the width of the original house (measured at widest point) for the purpose of calculating the “half width” limit for the extension 24 be half the width of the original house. The width of the original house should be calculated at its widest point. Under paragraph (ja) (see page 29) if the proposed extension is being joined to a previous enlargement, it will not be permitted development if the size of the total enlargement (being the proposed enlargement together with any previous enlargement) exceeds these limitations. For example, if a proposed extension of 3 metres in height is added to an existing extension which exceeds 4 metres in height, or if the proposed extension creates a total enlargement which has a width greater than half the width of the original dwellinghouse, it would not be permitted development.

Hi there,

I think this was covered earlier, but would be good to confirm a common understanding... so:

a) I think that the guidance on p18 is not relevant as the 3m extension at the end is acutally attached to an outrigger which is part of the original house. See image below (the black part is the original house):

b) The width of the entire house is around 5m. The width of the extension closest to the main building 2.5m.

So given a) and b) I guess this is PD?

EDIT 1: I think the following diagram from the p20 describes my scenario:

EDIT 2: This image contains more measurements all in 1 place to clarify the proposal:

 

[lt8480]

The frustrating thing about this is that any house with even a small original outrigger /extension on the back and which is less than one-half the width of the house, cannot have a rear extension under PD.

You can still do a rear extension under PD it just can't fully "fill" the gap and is restricted in width.

 

[lt8480]

Hi there,

I think this was covered earlier, but would be good to confirm a common understanding... so:

a) I think that the guidance on p18 is not relevant as the 3m extension at the end is acutally attached to an outrigger which is part of the original house. See image below (the black part is the original house):

b) The width of the entire house is around 5m. The width of the extension closest to the main building 2.5m.

So given a) and b) I guess this is PD?

EDIT 1: I think the following diagram from the p20 describes my scenario:

EDIT 2: This image contains more measurements all in 1 place to clarify the proposal:

That is correct if the existing outrigger is original or built pre 1948, otherwise the existing outrigger must be included in part of the PD assessment.

The existong outrigger doesn't look original based on plan form so you need to determine when it was built.

 

[tony1851]

You can still do a rear extension under PD it just can't fully "fill" the gap and is restricted in width.

To a point, but it depends on how wide the gap is between the side of the outrigger and the side wall of the extension.
There seems to be no hard-and-fast rule on this, but several appeal cases on the PJ website suggest that the gap has to be "material", ie 150mm won't do, but 800-1000mm might be OK. The reasoning is that when the gap is very small, the outrigger and extension 'read' as one wide extension.
This part of the p.d. rules really needs sorting out.

 

[lt8480]

To a point, but it depends on how wide the gap is between the side of the outrigger and the side wall of the extension.
There seems to be no hard-and-fast rule on this, but several appeal cases on the PJ website suggest that the gap has to be "material", ie 150mm won't do, but 800-1000mm might be OK. The reasoning is that when the gap is very small, the outrigger and extension 'read' as one wide extension.
This part of the p.d. rules really needs sorting out.

Which bit of the PD rules are you referring to?

If the outrigger is original then you can certainly butt up / connect to the outrigger, you just cant build more than 50% width of the whole house.

The restriction and the gap work around to which I think you are referring to is when there is a non original two storey extension and someone wants to in-fill the rest as single storey (the problem being if they touch the whole thing is assed against PD rules as one extension which is why you need a gap so they are assessed as separate extensions). E.g. this often happens when someone has built a 2-storey 3m deep extension on a detached property and then want to build a 4m deep infill extension, if they touch the whole thing fails as a "2 storey 4m deep extension".

 

[LukeB123]

Little bit late to the party on this one, but my general view is basically that of Napoleons a few posts ago. If it projects from the side, no matter how much, then its a side extension. It will catch some out, but it either does or doesn't. If it does by a 100 MM you need to comply with the side rules too.

lt8 - It isn't written anywhere in the PD rules regarding the "Gap" it's come from precedent and it would probably apply everywhere (single storey / 2 storey / side / rear etc.)

I.E. If you have a side wrap around extension and want to put a rear extension immediately next to it, if the extension "reads" as one then even if it is separated by a few millimetres, it's likely to be judged as one big extension (especially so If it has clearly been built to function as one large extension). Tony's last post puts it across well.

 

[napoleondynamite]

The OP said the rear-most extension would be built off an existing 3m deep addition. Therefore for planning purposes the total depth of 6m must be considered so the extension need prior approval or planning permission.

Looks like the infill extension might be ok as PD if 3m depth and no more than 1/2 width of the house. Subject to complying with all other restrictions e.g. matching materials, eaves height, overall height, etc.

 

[oculushut]

The OP said the rear-most extension would be built off an existing 3m deep addition. Therefore for planning purposes the total depth of 6m must be considered so the extension need prior approval or planning permission.

Looks like the infill extension might be ok as PD if 3m depth and no more than 1/2 width of the house. Subject to complying with all other restrictions e.g. matching materials, eaves height, overall height, etc.

hi - just wanted to clarify that the outrigger is original and the rear-most 3m extension is therefore attached to a part of the original building - we are rebuilding the existing 3m is extension. This is not an issue for PD (it is not 6m long). Perhaps my original drawing was not clear.
With regards to heights, the eaves of the rear-most extension eaves are below 3m (near the centre of the plot). The tallest part of the rear-most extension is below 4m and at the boundary of the plot. The materials will match the existing. Given all of this... I believe this is all within PD.

 

[tony1851]

Given all of this... I believe this is all within PD.

Correct.

 

[napoleondynamite]

hi - just wanted to clarify that the outrigger is original and the rear-most 3m extension is therefore attached to a part of the original building - we are rebuilding the existing 3m is extension. This is not an issue for PD (it is not 6m long). Perhaps my original drawing was not clear.
With regards to heights, the eaves of the rear-most extension eaves are below 3m (near the centre of the plot). The tallest part of the rear-most extension is below 4m and at the boundary of the plot. The materials will match the existing. Given all of this... I believe this is all within PD.

So are you 'rebuilding an extension', then extending out another 3 metres?

To keep it simple, the relevant measurement is the one from the original rear wall of the dwelling, to the rear-most extent of what you want to build. If that is more than 3 metres, then it's not PD.

 

[tony1851]

So are you 'rebuilding an extension', then extending out another 3 metres?

To keep it simple, the relevant measurement is the one from the original rear wall of the dwelling, to the rear-most extent of what you want to build. If that is more than 3 metres, then it's not PD.

I think he keeps saying that the outrigger is original?, so 3m out from the rear wall of the outrigger would be OK.

 

[oculushut]

I think he keeps saying that the outrigger is original?, so 3m out from the rear wall of the outrigger would be OK.

Right - so we are knocking down the current extension which is 3m long and attached to the original outrigger and then rebuilding this. The new extension will also be 3m long and attached to the original outrigger.

The difference between the old and the new is that the new 3m extension will not have a flat roof. It will have a pitched roof as shown in the diagram. Additionally, the window will be bigger.

 

[napoleondynamite]

Right - so we are knocking down the current extension which is 3m long and attached to the original outrigger and then rebuilding this. The new extension will also be 3m long and attached to the original outrigger.

The difference between the old and the new is that the new 3m extension will not have a flat roof. It will have a pitched roof as shown in the diagram. Additionally, the window will be bigger.

Its not about the difference between the old and the new, its about the distance from the original rear wall of the dwelling, to the rear most point of the proposed extension, which is sounds like is 6 metres. So planning permission or prior approval is required.

 

[oculushut]

OK - to be very clear: the distance from the original rear wall of the dwelling (the rear wall of the outrigger), to the rear most point of the rear-most proposed extension is 3m.