Read PD extension - measuring 'height'

[Alan Ambrose]

Hi,

 

Having recently won our PD rights back, I thought I might scope out a rear extension on our detached barn conversion. I see the 'rules':

 

Single Storey Extensions

– between 4m and 8m for a detached house

– max height of 4m and not higher than the ridge-line of the house
– max eaves height of 3m if within 2m of a boundary and not higher than the eaves of the house

– up to 50% of the original space around the house including any existing outbuildings or sheds etc.

 

My question is about 'max height'. We're on a small (5%) slope which runs parallel to the road and the main axis of the barn. There's also a step at the back of the barn from FFL to GL of about 55cm (image below) - measured in approx the middle of the building. At the front door the step is a normal 15cm.

 

If we had an extension, of course, we would prefer to have it at the same floor level.

 

So, the question is - would 'max height' be measured from the rear or front GL and at which end of the barn?

 

 

 

 

[ToughButterCup]

1 hour ago, Alan Ambrose said:

...

So, the question is - would 'max height' be measured from the rear or front GL and at which end of the barn?

...

 

In our case,  the location was chosen by the Planner.  

We have the same 'issue' as you have withour Piggery. The easiest place for the Planner to measure the height was right where he got out of the car. There, it was a few cm too high. Everywhere else, the eaves height was below what was required.  Man I was cross for a bit.

 

If I had the same challenge again, I'd change the ground level all round the building to  make the problem disappear. The consequences of not doing that are expensive. 

[Alan Ambrose]

Ah interesting, did his view stand up?

 

I think I have mostly convinced myself that it should be the highest bit of ground near the house. From here: https://assets.publishing.service.gov.uk/media/5d77afc8e5274a27cdb2c9e9/190910_Tech_Guide_for_publishing.pdf

 

“Height” - references to height (for example, the heights of the eaves on a house
extension) is the height measured from ground level. (Note, ground level is the surface of
the ground immediately adjacent to the building in question, and would not include any
addition laid on top of the ground such as decking. Where ground level is not uniform (for
example if the ground is sloping), then the ground level is the highest part of the surface of
the ground next to the building.)

 

And:

[joe90]

1 hour ago, Alan Ambrose said:

the ground level is the highest part of the surface of
the ground next to the building.)

That has always been my understanding .

[Alan Ambrose]

OK. We're not on much of a slope - but there's 80cm between one end and the other.

Edited October 28 by Alan Ambrose

[kandgmitchell]

In the GDPO regulations the legislation itself says:

 

(2) Unless the context otherwise requires, any reference in this Order to the height of a building or of plant or machinery is to be construed as a reference to its height when measured from ground level; and for the purposes of this paragraph “ground level” means the level of the surface of the ground immediately adjacent to the building or plant or machinery in question or, where the level of the surface of the ground on which it is situated or is to be situated is not uniform, the level of the highest part of the surface of the ground adjacent to it.

 

[Alan Ambrose]

Ah that muddies the water … that implies something more subtle - not the highest ground around the building, but the highest ground next to the building where you’re putting whatever you’re planning to put there

 

Seems to me that contradicts the eaves diagram, although I can see why.

 

I’ll do a bit more careful measuring up.

[joe90]

1 hour ago, Alan Ambrose said:

Ah that muddies the water …

I don’t think it does…..

 

16 hours ago, kandgmitchell said:

“ground level” means the level of the surface of the ground immediately adjacent to the building or plant or machinery in question or, where the level of the surface of the ground on which it is situated or is to be situated is not uniform, the level of the highest part of the surface of the ground adjacent to it.

I think that confirms it’s measured from the highest ground adjacent to the build.

[Canski]

3 minutes ago, joe90 said:

I think that confirms it’s measured from the highest ground adjacent to the build.

Interesting. Is this method of measurement the same for garden rooms? I excavated 1 m into a slope and built it a little bit higher than the 2.5 m max at the high end which is about 1.7 m above the retaining wall that is holding the slope back.

[joe90]

3 minutes ago, Canski said:

Interesting. Is this method of measurement the same for garden rooms? I excavated 1 m into a slope and built it a little bit higher than the 2.5 m max at the high end which is about 1.7 m above the retaining wall that is holding the slope back.

I think so, it all comes under the PD heading. If you got away with it and your neighbours are not bothered the win win.

[Canski]

7 minutes ago, joe90 said:

I think so, it all comes under the PD heading. If you got away with it and your neighbours are not bothered the win win.

No complaints from the neighbours but I am slightly concerned that someone from the council may pop by seeing as we are nearing completion certificate stage.

[Redbeard]

40 minutes ago, Canski said:

Is this method of measurement the same for garden rooms? I excavated 1 m into a slope and built it a little bit higher than the 2.5 m max at the high end which is about 1.7 m above the retaining wall that is holding the slope back.

 

Is your garden room masonry, and does the room wall itself form the retaining wall? If not, and you have effectively retained 'the end of a swimming pool' inside  which you have built the garden room then, according to my LA, the measurement is from the flat bottom of that 'swimming pool'. If you have properly built in to the ground, and the ground abuts the building then IMO the height is measured from that 'highest' level. In my case I retained a bank, and built a TF shed from the bottom of the retaining wall. Appr 1.2m was retained, so 1.8m to eaves height, therefore PD with ridge ht of 4m. "No", said the LA! "It's more than 2.5m above GL at the eaves, so it's not PD". So it has Planning Permission.

[Canski]

23 minutes ago, Redbeard said:

Is your garden room masonry, and does the room wall itself form the retaining wall? If not, and you have effectively retained 'the end of a swimming pool' inside  which you have built the garden room then, according to my LA, the measurement is from the flat bottom of that 'swimming pool'. If you have properly built in to the ground, and the ground abuts the building then IMO the height is measured from that 'highest' level.

Ahh I see. I've just been checking and I had originally got planning for the 'garden room' (man cave) and the drawings that I submitted no dimensions on them so I think I should be ok as long as I don't extend the 'bin store' upwards. Excuse the mess in the photo its work in progress 🙂

 

[Alan Ambrose]

>>>

4 hours ago, Alan Ambrose said:

Ah that muddies the water …

I don’t think it does…..

<<<

 

OK take this real life example - not a million miles from what I want to do. Imagine an extension with ridge and eaves as below. Question is, am I measuring the 'ground level' as GL (a) or GL (b)? The difference is about 3 bricks i.e. ~0.25m / a foot. No so much, but by the time we get some decent insulation in, we would like to get the max height we can.

 

[markc]

In this instance I would say GL (a) as this is the highest point adjacent to your new structure

[joe90]

22 minutes ago, markc said:

In this instance I would say GL (a) as this is the highest point adjacent to your new structure

+1 (IMO) 

[DevilDamo]

@Canski Excavations to form retaining walls are deemed as an engineering operation, which require Planning. Assume you ended up getting or needing Planning for that reason?

 

@Alan Ambrose The guidance is very clear when measuring on sloping sites. No need to over complicate it. 

[Alan Ambrose]

@DevilDamo - so does that mean GL (a)?

[DevilDamo]

5 hours ago, Alan Ambrose said:

@DevilDamo - so does that mean GL (a)?

Is that adjacent to the structure…