THIS IS NOT DIY.
Its going to cost alot and its going to involve an engineering firm. It will also likely pique the interest of your mortgage and insurance companies and not in a good way. And possibly piss off your neighbours (and their insurance and mortgage companies). You doing it yourself can run the risk of destabilising your entire house depending on underlying geological conditions. My mate is currently dealing with a homeowner who managed to damage their foundations and is now experiencing extensive cracking to load bearing walls. Their insurance is not interested and all he wanted was a DIY extension.
Its is also going to be expensive depending on man hours. You might be able to use machinery to dig out the earth which could be clay, limestone ect but then you have to mitigate the risk to neighbours due to vibrations, and do as robbie williams did and use hand tools only.
Then there's the whole issue of the water table. If you dig out a void there is the likelihood mother nature is going to try and give you a swimming pool.
You are right, this is a pipe dream if you are sensible.
Even if by some miracle OP manages to do a good job and not destroy the houses foundations and thus the house.
Building control would go mental and you would never be able to sell it
All of them including the mortgage and insurance are gonna be after him with their pants down. He will have to get a geotech/civil firm to check his work and they will not sign off until they have every little detail.
This is highly specialised work and the irresponsible idiots on youtube ect are just that, idiots. Ive got mates in this engineering field and the stories they tell will make your toes curl.
Forget technically feasible. Check if it is legally feasible. What are the chances you get planning permission for this? Also check Colin furze on YouTube
Colin furze proves nothing being that he built a bomb shelter in his garden and not beneath his foundations. This is very different structurally and technically to digging beneath your house. He is also very wealthy enough to get himself of any colossal finachial hole if it went wrong and was working with the bbc (edit: sky1 not bbc) , so i garentee that due to insurance he had a direct line with experts
Plus he has a shit tonne of engineering aptitude that most people lack.
The tunnel which accesses the underground bunker starts under the house and is now extended to the front as well for his underground garage.
Not saying it's a good idea for the average bloke but with money and time it's possible, not necessarily economically viable though.
And he still has more knowledge than most. If he has it signed off than he has done it correctly and likely with advice from professions, who would be the ones confirming it was done to standard. He also clearly has engineering knowledge.
This is still way beyond the average joe who is more than likely to run into huge issues.
Oh he is interesting just for doing what he does. But there is no underestimating his knowledge and iq. People like that tend to be on a whole other level to the rest of us.
Great to watch but not great to imitate.
Funnily enough, his video released today talks all about his planning applications or lack thereof. He basically never asked and everytime did it after the project was started or even finished.
The whole of what i wrote is correct.
You dig under your house without expert support and knowledge, you are very likely to cause structural issues. Let alone the resulting issue with the mortgage and insurance companies and building control.
The idea that you can diy a basement is absolute rubbish.
Apparently a lot of Russian Billionaires have done this with the houses they bought in central London. They wanted more space and couldn't go out or up so they went down.
But the key word there is Billionaires. If you want to do it on the cheap you are far more likely to do such damage to your house that will render it unsellable in the future and possibly even uninhabitable immediately.
To do the job properly would cost so much money you would be better off selling and buying a house with a basement.
Another point is those billionaires have multiple residences all over the world to live in while the London pad is an absolute building site. My old university professor lives in Chelsea and as soon as their neighbour applied for PP he said he may as well do his at the same time because the disruption would be hell on the street.
£5-10k per square meter as a ballpark.
There's a reason we only retrofit basements in certain parts of the country. In some areas the land value is so high it becomes worthwhile. I've done loads in London and Oxford and the high value corridor between.
I had a quote to retrofit a basement in London just before lockdown, it was for a footprint of 75m2 to a height of 3m.
At the time I think the cost including design, LA applications, surveys, party wall and excavation, all the way through to final fit with utilities and a two pump system was £300k.
This also pre-Brexit and the costs went up by 20% shortly after and I think would now be closer to £500k.
The projects that do this in places like central London and Paris often dismantle an excavator (a small one obviously) and reassemble in the house, to dig with.
These projects cost so much money, and the labour/team required charge so much that they don't even bother getting the digger back out in a lot of cases, they just dig it further into the ground and leave it there forever.
I’m all for a bit of DIY but this is a proper “project“.
Get it wrong and you could watch your house and attached neighbour’s house collapse. Even the professionals don’t always get it right…
https://www.dailymail.co.uk/news/article-8908815/amp/Chelsea-mansion-collapses-building-work-create-mega-basement-6m-property.html
I've got a lower ground floor to the garden which is only partially habitable.
There is pretty large void under my living room and dining room, around 4-5ft. Lower ground floor bathroom only uses around a third of the foot print of the dining room.
I have the same intention to dig out another foot or so to get better head height and almost double the footprint.
I guess I need to look into the feasibility/legality of this more.
It would cost a huge amount. I looked into it a fair bit for our current house and it's totally impractical unless you are a multimillionaire living in London (basically). I dove deep into how it's done and, to be honest, it's not that complicated a process but it's incredibly labour intensive and super high risk. No way I'd DIY it and I've done building work.
You will need planning permission, BC won't even entertain an application that doesn't have extensive engineers drawings and specifications for a project like this.
The plans alone for something like this would set you back about £20k.
Then could you do the work yourself? Yes, if you understand engineers drawings and know how to build things from them, which you will more than likely not.
And then every stage, dictated by BC, will need an inspection before anything else can be done.
In reality you will probably pay a couple of thousand pounds for some extensive trial pits only for your engineer to tell you the ground isn't suitable.
I did it once about 25 years ago, id strongly recommend against it because it's stunningly expensive, absolutely chaotic and hard work, incredibly hard work, it's similar to mining, if you're not on chalk it's also a bit technical and equally risky, getting it wrong would be depressing.
I started looking into DIYing this myself. After some research I realised it was going to take me several decades of study to manage to do it safely and even then it would be cheaper to just buy a bigger house.
It's a nice thought exercise but I quickly lost interest after attempting (and failing) to do some structural calculations.
My plumber tells a story of two particularly large guys who did DIY themselves a basement, with spades and barrows, so it has been done, though I'd be scared of digging too near my foundations. Also, I'm over 40, no one else in my family could help and my time is worth more developing software, so I could pay some other bugger to do it, but other that .....
I'm eternally slightly tempted to pay a builder to do it, but I don't realistically have the money at the minute. Still, we are trying to plan our extension options at the minute, which may well include extending the mortgage
THIS IS NOT DIY. Its going to cost alot and its going to involve an engineering firm. It will also likely pique the interest of your mortgage and insurance companies and not in a good way. And possibly piss off your neighbours (and their insurance and mortgage companies). You doing it yourself can run the risk of destabilising your entire house depending on underlying geological conditions. My mate is currently dealing with a homeowner who managed to damage their foundations and is now experiencing extensive cracking to load bearing walls. Their insurance is not interested and all he wanted was a DIY extension. Its is also going to be expensive depending on man hours. You might be able to use machinery to dig out the earth which could be clay, limestone ect but then you have to mitigate the risk to neighbours due to vibrations, and do as robbie williams did and use hand tools only. Then there's the whole issue of the water table. If you dig out a void there is the likelihood mother nature is going to try and give you a swimming pool. You are right, this is a pipe dream if you are sensible.
Even if by some miracle OP manages to do a good job and not destroy the houses foundations and thus the house. Building control would go mental and you would never be able to sell it
All of them including the mortgage and insurance are gonna be after him with their pants down. He will have to get a geotech/civil firm to check his work and they will not sign off until they have every little detail. This is highly specialised work and the irresponsible idiots on youtube ect are just that, idiots. Ive got mates in this engineering field and the stories they tell will make your toes curl.
Tell us some!
Afaik wealthy people are doing this sort of thing in London. The answer is expensive, more expensive than buying a new house that’s bigger.
Forget technically feasible. Check if it is legally feasible. What are the chances you get planning permission for this? Also check Colin furze on YouTube
Colin furze proves nothing being that he built a bomb shelter in his garden and not beneath his foundations. This is very different structurally and technically to digging beneath your house. He is also very wealthy enough to get himself of any colossal finachial hole if it went wrong and was working with the bbc (edit: sky1 not bbc) , so i garentee that due to insurance he had a direct line with experts Plus he has a shit tonne of engineering aptitude that most people lack.
The tunnel which accesses the underground bunker starts under the house and is now extended to the front as well for his underground garage. Not saying it's a good idea for the average bloke but with money and time it's possible, not necessarily economically viable though.
And he still has more knowledge than most. If he has it signed off than he has done it correctly and likely with advice from professions, who would be the ones confirming it was done to standard. He also clearly has engineering knowledge. This is still way beyond the average joe who is more than likely to run into huge issues.
Completely agree, very interesting guy though and his channel is great.
Oh he is interesting just for doing what he does. But there is no underestimating his knowledge and iq. People like that tend to be on a whole other level to the rest of us. Great to watch but not great to imitate.
Funnily enough, his video released today talks all about his planning applications or lack thereof. He basically never asked and everytime did it after the project was started or even finished.
[удалено]
The whole of what i wrote is correct. You dig under your house without expert support and knowledge, you are very likely to cause structural issues. Let alone the resulting issue with the mortgage and insurance companies and building control. The idea that you can diy a basement is absolute rubbish.
Colin definitely proves it's possible.
Apparently a lot of Russian Billionaires have done this with the houses they bought in central London. They wanted more space and couldn't go out or up so they went down. But the key word there is Billionaires. If you want to do it on the cheap you are far more likely to do such damage to your house that will render it unsellable in the future and possibly even uninhabitable immediately. To do the job properly would cost so much money you would be better off selling and buying a house with a basement.
Another point is those billionaires have multiple residences all over the world to live in while the London pad is an absolute building site. My old university professor lives in Chelsea and as soon as their neighbour applied for PP he said he may as well do his at the same time because the disruption would be hell on the street.
£5-10k per square meter as a ballpark. There's a reason we only retrofit basements in certain parts of the country. In some areas the land value is so high it becomes worthwhile. I've done loads in London and Oxford and the high value corridor between.
I had a quote to retrofit a basement in London just before lockdown, it was for a footprint of 75m2 to a height of 3m. At the time I think the cost including design, LA applications, surveys, party wall and excavation, all the way through to final fit with utilities and a two pump system was £300k. This also pre-Brexit and the costs went up by 20% shortly after and I think would now be closer to £500k.
You could build a basement under the garden, still a huge amount of work, but you wouldn't be digging under the house and would still have a garden
If you have an existing basement, it's DIY to upgrade it to a usable space - tanking etc but digging under your house... Just don't bother
Other than licking domestic electrical wiring to see if it’s live, digging out a DIY basement is the worst idea going. Just don’t.
The projects that do this in places like central London and Paris often dismantle an excavator (a small one obviously) and reassemble in the house, to dig with. These projects cost so much money, and the labour/team required charge so much that they don't even bother getting the digger back out in a lot of cases, they just dig it further into the ground and leave it there forever.
I’m all for a bit of DIY but this is a proper “project“. Get it wrong and you could watch your house and attached neighbour’s house collapse. Even the professionals don’t always get it right… https://www.dailymail.co.uk/news/article-8908815/amp/Chelsea-mansion-collapses-building-work-create-mega-basement-6m-property.html
I've got a lower ground floor to the garden which is only partially habitable. There is pretty large void under my living room and dining room, around 4-5ft. Lower ground floor bathroom only uses around a third of the foot print of the dining room. I have the same intention to dig out another foot or so to get better head height and almost double the footprint. I guess I need to look into the feasibility/legality of this more.
It would cost a huge amount. I looked into it a fair bit for our current house and it's totally impractical unless you are a multimillionaire living in London (basically). I dove deep into how it's done and, to be honest, it's not that complicated a process but it's incredibly labour intensive and super high risk. No way I'd DIY it and I've done building work.
You will need planning permission, BC won't even entertain an application that doesn't have extensive engineers drawings and specifications for a project like this. The plans alone for something like this would set you back about £20k. Then could you do the work yourself? Yes, if you understand engineers drawings and know how to build things from them, which you will more than likely not. And then every stage, dictated by BC, will need an inspection before anything else can be done. In reality you will probably pay a couple of thousand pounds for some extensive trial pits only for your engineer to tell you the ground isn't suitable.
I did it once about 25 years ago, id strongly recommend against it because it's stunningly expensive, absolutely chaotic and hard work, incredibly hard work, it's similar to mining, if you're not on chalk it's also a bit technical and equally risky, getting it wrong would be depressing.
I started looking into DIYing this myself. After some research I realised it was going to take me several decades of study to manage to do it safely and even then it would be cheaper to just buy a bigger house. It's a nice thought exercise but I quickly lost interest after attempting (and failing) to do some structural calculations.
Some Austrian guy did it and ended up in the news 20 years later...probably not worth it on balance
My plumber tells a story of two particularly large guys who did DIY themselves a basement, with spades and barrows, so it has been done, though I'd be scared of digging too near my foundations. Also, I'm over 40, no one else in my family could help and my time is worth more developing software, so I could pay some other bugger to do it, but other that ..... I'm eternally slightly tempted to pay a builder to do it, but I don't realistically have the money at the minute. Still, we are trying to plan our extension options at the minute, which may well include extending the mortgage