2.5m max height for PD outbuilding

[eb28]

Hi everyone

I'm planning a garden room and was left a bit confused over the maximum overall height, if the building is within 2m of a boundary.

I have a sloping garden as per the picture. Fence at the back with a public pathway over the fence. I believe that path land is registered to the church.

The green line is the slope of the ground before my project, and in red is roughly what I hope to achieve, exaggerated a bit to highlight what I'm asking.

I've read that the 2.5m is measured from the highest adjacent land to the building. But with my planned steps down to the building (to allow for bifolds to open), I'm wondering where the 2.5m is measured from (the different coloured arrows).

Another question is now I have seen this page
http://www.permitteddevelopment.org/The-Ambiguities-of-the-PD-Legislation.php
The last point number 17 has a sub-note, which concerns me. That says that the slope isn't counted if it's a detached building, but I can't find the official reference for that.

I do plan to get a certificate of lawful development, but wanted to go in armed with info.

Many thanks in advance.

 

[motorbiking]

height from the point at the back where the fence/wall is. If there is a complaint, they will measure it from the ground to the highest point of the offending face. if nobody minds after 4 years it didn't matter anyway.

With a flat sloping roof, the 2.5m limit isn't a problem. Its easily high enough to get an insulated roof with a decent ceiling height within that limit.

 

[mrrusty]

point 17 http://www.permitteddevelopment.org/The-Ambiguities-of-the-PD-Legislation.php

 

[Notch7]

the planning jungle is the authority on PD

heres one example

https://planningjungle.com/2018/02/...ons-8-additional-appeal-decisions-total-1013/

and no2 (which may have been updated now)
https://www.molevalley.gov.uk/CausewayDocList/DocServlet?ref=MO/2012/1611&docid=435455

 

[eb28]

Thanks all.
The 2.5m is usually enough I agree, but I would need to dig quite a lot on the high side to get 2.5m, if measuring from the ground at the fence. It's a reasonably large room at 24 sqm, so a lot to excavate if measuring the height from the fence.

Thanks for all the links. I've also been looking at a few appeal decisions found online. Most of what I'm seeing seems to point at my blue arrow in the picture being the reference for "height" and that reference datum doesn't change as you move around the building.

The technical guidance says:

If any part of the building, container or enclosure is within two metres of the
boundary of the area around then house, then the height limit for the whole
development is restricted to 2.5 metres if it is to be permitted development. ​

But then page 6 of the guidance, when defining "height" says:

‘Height’ - references to height (for example, the heights of the eaves on a house
extension) is the height measured from ground level(*3). Ground level is the surface of
the ground immediately adjacent to the building in question. Where ground level is
not uniform (e.g. if the ground is sloping), then the ground level is the highest part of
the surface of the ground next to the building.

*3 This will be the level of the natural ground and would not include any addition laid on top of the
natural ground such as a patio. ​

http://www.permitteddevelopment.org/Appeal-Decision-127.php seems to agree that my blue arrow would be ok.

So does the link from Notch7, thank you. https://www.molevalley.gov.uk/CausewayDocList/DocServlet?ref=MO/2012/1611&docid=435455 pages 36/37 gives more detail about this "loop hole" that still doesn't seem to be addressed.

Various appeal notices, including some recent ones
MC/17/4217

"The Inspector considered that the height should be measured from the ground level at the highest part of the surface of the ground level next to the building. The Inspector concluded that the Council did not take into account the Technical Guidance’s advice and that the decision that the proposed development was unlawful was not well-founded"​

APP/R4408/X/20/3255825

"It is necessary therefore to establish the highest pre-existing ground level adjacent to any part of the external walls of the proposed building."​

So the concensus from these links, the way I read them, is that I could measure from my blue arrow. The only exception being the "point 17" subnote here http://www.permitteddevelopment.org/The-Ambiguities-of-the-PD-Legislation.php
But then it's just their "take"

Although I plan to have steps down to the center of the front elevation, I could still have some natural ground level at a corner, to measure from if needed in future.

 

[motorbiking]

Are you building within 1m of the boundary? Needs to be from fire resistant materials if so, as over 15m2.