Underground Basment

FreeBear

There have been a couple of underground extensions featured on GD. The one you might be thinking of is this one - http://www.hogartharchitects.co.uk/grand-designs/

I'd love to have a deep basement, but like the OP, it would have to be separate from the house... It would probably be more fitting to describe the construction as a bunker (are there building regs for bunkers, and would it fall under permitted development ?)...

Ozzuk

I have a basement, at least that is how it was described in the EA particulars but actually only half of it is underground due to living on a hill. So you smart lot, what would that be called!

Ground floor? Underground floor? Lower floor?

lstar337

FreeBear wrote: »

There have been a couple of underground extensions featured on GD. The one you might be thinking of is this one - http://www.hogartharchitects.co.uk/grand-designs/

The one I was thinking of was bought by artists I believe and it was like a rabbit warren underneath. They were going to rent the various underground rooms to artists to use as studios.

Davesnave

I'm not so sure as you guys that one needs any fancy materials when building a structure like this, since there are plenty of cellars in existence where nothing more than random stone and house bricks have been used, albeit skilfully.

My BiL discovered he had an 'underground basement' when clearing the oversite from his development. He was about done with the digger, when a small hole opened up in what turned-out to be the brick roof of a room roughly 7m x 3m, but only just about high enough to stand up in.

Of course, he covered it up, pronto, thinking it might have some historic significance, and not wanting the building inspector or his loony neighbour to see it.

However, much later on, he built steps down to this room, which by then he knew was a reservoir, quite common in the area and used for businesses with significant water demands. From items removed, it would seem that the reservoir was partially filled-in around Victorian/ early Edwardian times.

So, this 'basement' has been in existence for maybe 200 years and doesn't have any concrete or reinforcing material in the walls or roof. I'm not sure about the floor. It does have a reinforced concrete cover now; after all, people park cars on top of it!

PasturesNew

Nice video to watch
http://www.shedworking.co.uk/2011/11/weve-covered-various-underground.html

GDB2222

Davesnave wrote: »

I'm not so sure as you guys that one needs any fancy materials when building a structure like this, since there are plenty of cellars in existence where nothing more than random stone and house bricks have been used, albeit skilfully.

My BiL discovered he had an 'underground basement' when clearing the oversite from his development. He was about done with the digger, when a small hole opened up in what turned-out to be the brick roof of a room roughly 7m x 3m, but only just about high enough to stand up in.

Of course, he covered it up, pronto, thinking it might have some historic significance, and not wanting the building inspector or his loony neighbour to see it.

However, much later on, he built steps down to this room, which by then he knew was a reservoir, quite common in the area and used for businesses with significant water demands. From items removed, it would seem that the reservoir was partially filled-in around Victorian/ early Edwardian times.

So, this 'basement' has been in existence for maybe 200 years and doesn't have any concrete or reinforcing material in the walls or roof. I'm not sure about the floor. It does have a reinforced concrete cover now; after all, people park cars on top of it!

Good point. We have a victorian house in the family. We investigated the foundations, and they are only about a foot deep, built on shrinkable London clay. It's amazing what you can get away with.

It also has a brick-built cellar. Some of the walls of the cellar are not underground as the house is built on a slope. As far as I can see, the underground walls of the cellar are several courses of brick thick. It's no different, in principle, from building a retaining wall out of bricks. There's no doubt it can be done, with sufficient skill. The walls also have the weight of a three storey house on top, which presumably helps stabilise them.

Do you think the OP on this thread has the required skill?

Davesnave

GDB2222 wrote: »

Do you think the OP on this thread has the required skill?

No, I don't, but that's a seperate issue. The vaulted roof alone, made from nothing more than house bricks, would have taken considerable skill to construct.

I still can't understand how this 'reservoir' stored water as the walls look remarkably permeable, but items thrown into it, like the glass surrounds for old oil lamps, would have smashed if it had been empty when that happened. Perhaps it was just a way of trapping water from an underground spring on a 'less out than in' principle.

Biggles

G_M wrote: »

Did someone mention Building Control?

Surely the council don't car as long as it's invisible when finished? Otherwise what's the point of re-laying the garden on top......?

I can't see that the council will need planning permission (though will the entrance door* be above ground?) but I should have thought Building Regs would still apply; perhaps very forcibly in a case like this.

You might think, 'They'll never know', but when you come to sell and the buyer's surveyor sees it, questions will be asked and it could make the property unsellable without the proper permissions.

* What might that be, a garden shed with a lift inside?

martinsurrey

Davesnave wrote: »

So, this 'basement' has been in existence for maybe 200 years and doesn't have any concrete or reinforcing material in the walls or roof. I'm not sure about the floor. It does have a reinforced concrete cover now; after all, people park cars on top of it!

I wonder how many of the other ones like it suffered a catastrophic failure in the intervening years and are no longer around for people to find? and how many people died as a result?

https://en.wikipedia.org/wiki/Survivorship_bias

FreeBear

Biggles wrote: »

I can't see that the council will need planning permission (though will the entrance door* be above ground?) but I should have thought Building Regs would still apply; perhaps very forcibly in a case like this.

* What might that be, a garden shed with a lift inside?

Have had a brief look at the subject of planning permission & building regs... It is classified as an engineering operation, so would need to comply with all the regulations currently in force. Depending on the size and location of the excavation, it may fall within the parameters for permitted development, but a planning application would still need to be made - If it does not affect the character of the building (and it isn't a listed property), the application stands a good chance of being approved.

It is a minefield out there, so before embarking on any such project, it is worth getting an architect on board that is familiar with subterranean developments. Despite what one might read on the internet, it not a DIY project !