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When I previously presented the dream of making a basement room for a home theater, you advised against these considerations, but I never understood why. Then I heard that the neighbor had dug out under their house, which is admittedly much older and more stable, but still.

It's a bit annoying when I already have a 2-meter high empty space under the house. If I dug out 50cm more, couldn't I almost piece together a room? Would the house really fall apart just because of that? :)

kallaren-mar-inte-bra141.jpg

 
  • Blueprint sketch of a house cross-section, showing dimensions with a focus on basement height. Includes measurements like 2.40m height and 4.40m width.
If you just cast something for the walls to stand on that is a bit below the excavation, then it shouldn't be a problem. You will probably need to dig, cast, and brick in stages under your existing walls. To get a more detailed understanding of what to do, you should probably have a chat with someone who is more knowledgeable.
 
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have a feeling the room will be low-ceilinged with the floor and ceiling
 
Everything can be solved, it's just a slightly different length of the journey. Personally, I lack a big basement in my house, so I'm probably just envious.

Surely it can be solved, what I spontaneously think of is that you will have to work quite a bit with soundproofing/resonance measures to be able to play loudly in there. Additionally, a long narrow room is not optimal for a home theater, rather a room that's a bit wider than it is long. But who wouldn't want a truly dedicated home theater room?
 
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norrbottenstorpet said:
Additionally, a long narrow room is not optimal for a home theater, rather a room that is a little wider than it is long.
Well, you can sit facing a long side :)

Yes, or I could have it up there on the second floor anyway, but darn staircase is so terribly placed... sigh...

byggare henke said:
have a feeling the room will have a low ceiling with the floor and the ceiling
Well, as I said, you have to dig down a bit. :)
 
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how new is the house??
wondering if you encounter the insulation.
then the indoor environment there is probably not so good.
I think you should install some vents down there.
don't see any
 
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1981, and yes indeed, there are vents everywhere although they might not be visible in the picture. Some might have taken a hit so the openings aren't quite as they should be, but they are there anyway.. :)
 
A bit from home, I saw an older house last spring where they had made a hole right through the basement and inserted a hefty HEA beam. I wondered what they were going to do. Now I've seen that they've demolished a part of the basement where the beam is, built up new walls, and cast a new slab, and they seem to be moving bit by bit. So it looks like they're replacing the entire basement in stages.

Sure, everything is possible, but would one do it oneself? Not me, I think, and at this place, it also looks like professionals are at work. That's what I think when I see your project too - sure, it's doable, but is it a DIY job? For some maybe...

You have to extend the foundation walls downward, dig and pour and build in stages as Gnilrub says. How much you can do at a time and how it should be done, you probably need expert advice on... Then when it's done (or almost, perhaps practical to have a bit open to cart out the debris), dig out the bottom. It might be necessary to move or deepen the plumbing. Then lay the gravel, insulate, install heating and pour. The external drainage probably needs to be redone, deeper down, and then it's just as well to insulate externally too. Then all that's left is the interior! (Well, and a little electricity and such.)

Compared to typical "basement projects" (haven't done one myself, but many who have done it seem to think it's the most tedious thing they've done), this sounds like one of those times two considering the foundation walls. But it is doable, it's just a whole lot of work (some of which is not entirely straightforward) and probably not cheap either.

Not to be negative, just realistic. But it would be cool if you pulled it off.
 
A lot of work. Moreover, it's important to do it right and not least to consider the ground conditions. Is the ground stable and will it remain in place when you dig, or will it collapse? A link to someone who managed to do what you're considering: http://www.james-lotta.se/utgravn_kallare.htm
Good luck!
 
What does the city plan say? Do you get a building permit for a basement? Expensive to restore afterward.
 
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um, do you need a building permit for that then.. not good, hehe
 
I don't think a building permit is needed for this. You already have a basement and if you dig deeper, no one will lose their view because of it.
 
It will be an expensive unauthorized construction. There is no basement now, and then you significantly alter the building. Additionally, the municipality's sewage system may not be deep enough to connect floor drains from the new basement.
 
2 m in ceiling height? I am 1.95. Assumed it was a basement. Looks more like it at least.
 
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um, now I do have my own brunn so to speak.
But yes, sure, one should have tried applying first if required.
 
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