Woodwork Outbuilding under Permitted Development

[aveatry]

I would say that you actually have 3 neighbours fences as in that corner is the house that has had all the work and extension done to it.
If you are building right up to the fence i might be an idea to think abut who has responsibility for the them for future replacement problems.
I would leave a gap for maintenance and its always then a good place for keeping bits stuffed out of sight.
I wouldn't tell them but would do whatever sound insulation you can to mitigate noise - which will be an added benefit of insulating for winter. And maybe dig that end lower before you start to remove the step-up then the neighbours will not see it.

 

[aveatry]

Build it to PD standards, that way you will shut any adverse comments down.

But it still wont stop/ prevent them from putting in a noise nuisance complaint with the council

 

[Shlumaan]

I'm actually wondering why there's that step-up section at all, could there be pipe work or something else that required the elevation? Can't think why the previous owner would want to make their shed stick up so high have their ground...?

 

[aveatry]

I'm actually wondering why there's that step-up section at all, could there be pipe work or something else that required the elevation? Can't think why the previous owner would want to make their shed stick up so high have their ground...?

It looks to me that ther is a slight slope down from the neighbours over there to your house and instead of a slope a previous owner has put in a step.
If you dug down to flatten it I think you will need to add extra gravel board then you are talking replacing the fence post/gravel board system with a concrete, mayme a 12inch high concrete gravel board then on your side you will see the full 12 inch but from the end of their garden they will only see 1 inch sticking up ( if it slopes )

 

[aveatry]

Ohh wait a min - on further inspection it may be the base of an anderson shelter, or other type of bomb shelter- how old are the houses

 

[Shlumaan]

1930s I believe. Either way I don't like the sound of this as it might translate into not being able to get my full 2.5m height plus to start meddling with the neighbours fencing... What's an Anderson shelter and how can I find out before I start digging?

 

[Diver Fred]

Anderson Shelter - https://andersonshelters.org.uk/

But the base in your garden is unlikely to be the base to one as Anderson Shelters were dug into the ground.

 

[Shlumaan]

Question is could they have built the concrete over something like that? Or else what could explain the such step up above the ground? Essentially I want to know if I'd be able to take the platform down and build something with full permitted height and not get into issues of rebuilding fences. Any thoughts?

 

[aveatry]

I only said anderson shelter as that is the most famous type that people had in their back garden.
I am still going with the base of an air raid shelter and the age of your house only adds to the theory. I am guessing you are near or in a big city likely to be hit. Also it sits as far away from the house as possible to get away from flying bomb debris. And its the right size.
Its not like people have built over it - you are looking at the shelter and the only new bit is the cap to fill it in.
Look here the blue yellow and red are what I think are the outlinds of the base and the white is a later addition of badly poured concrete after filling in the shelter below, that top layer of concrete is too rough to of been a base for a shed. Look were the white new concrete meats the yello corner follow that corner to the red line.
The blue area looks like the entrance.

 

[aveatry]

Look at this picture, different shape but same thing https://www.layersoflondon.org/map/records/unearthing-an-air-raid-shelter-at-edgware-junior-school
Google garden air raid shelter and go images and you will find loads similar.

 

[aveatry]

1930s I believe. Either way I don't like the sound of this as it might translate into not being able to get my full 2.5m height plus to start meddling with the neighbours fencing... What's an Anderson shelter and how can I find out before I start digging?

As the fence is at the bottom of both of your gardens then the fence maybe jointly owned between you and them.

 

[Shlumaan]

Thank you @aveatry, I trust your judgement but let's hope it's nothing after all. Assuming you're correct, will it be straight forward to flatten the area and build on top?

 

[^woody^]

But it still wont stop/ prevent them from putting in a noise nuisance complaint with the council

Just like cutting the grass and trimming the hedges won't.

 

[aveatry]

Thank you @aveatry, I trust your judgement but let's hope it's nothing after all. Assuming you're correct, will it be straight forward to flatten the area and build on top?

No don't trust me, i am not a historical expert and am only looking at your pictures. It may be hard work removing any of as because i think that old concrete is very strong. And should you actually remove it as an historical part of the house, I think i would dig out the infill and explore it, if it is an air raid shelter there is no telling how deep or big it is. You could then build your workshop over it and have a trap door access to it ready made extra space.

 

[aveatry]

Just like cutting the grass and trimming the hedges won't.

No not like cutting the grass at all