The more I look at the average urban and suburban sprawl the more I feel that actually what we should be doing is putting the roads deep down, the houses just under the surface with light pipes and the gardens and parks on top...Hobbiton? possibly :-)
What do you think are the pros and cons of this from a cost/benefit environmental and general living feeling?
Costs of excavation (especialling tunneling for roads $$$). Somewhere to put the spoil. Very large amounts of concrete used. Vulnerability to flooding.
Earth sheltered housing has a lot going for it - but will be the option of the well off - can't be done for the price of starter homes.
This has been suggested as an approach to dealing with much higher population levels in future. You can have much higher density housing below the surface yet retain a green countryside appearance above. You can have fields orchards and houses occupying the same space. If on todays housing estates houses occupy 1/3 or 1/4 the area, undergruond they could occupy almost 100%, tripling or quadrupling density.
The biggest problem is cost. Building a house underground requires a far stronger structure than one on the ground. There are also additional costs such as soundproofing for houses under roads, drainage, fire escapes, climate control, etc.
The requirement for window area also means that above ground wont be clutter free, and cant be used like a ploughed field. It can however be used for some growing applications.
The inability to look out the window is very undesirable to most people, though periscope windows are a possibility.
Tunnels are vastly more expensive than surface roads, and having roads on the surface with houses underground would support far more population than all on top as now. In the distant future, as populatoin rises even more, roads underground might become desirable too. Such roadways could be on a different level than the housing, so one could have separate fully packed layers of roads, housing, factories, and basic services.
Lets say (havent checked figures now, just ballparking) that 5% of British land is built on, and out of that the house occupies 33% of that land. Converting to underground housing on 2 storeys would then give us an increase in total housing area of around 60 times the present house area.
Nearly everything comes down to cost in the end, and the cost of doing this today on a mass scale is prohibitive. Its also not well enough accepted to support good sale prices for such properties. It also brings more disadvantage than advantage in reality, though when populations are 50x as large it may be the other way round.
NT
If its done as a one off house, yes it costs, though jcbs make that not excessive any more. But if it were done en masse, one would only need to excavate a foot or so, build the layer of housing then put the soil on top of them. The ground level would become higher. More concrete would be required to support a foot of earth on the roof, but not as much more as sinking just one house would need. Also with no exterior walls on dense housing there would be no need for brickwork, poured and block walls would be the standard, saving on brickwork.
NT
Cons ====
o Damp/drainage. o Radon, and other heavier than air poisonous and toxic gases. o Sewerage and waste water disposal becomes more difficult. Either considerably deeper, and therefore more expensive, or widespread use of S*n*f*o*s. Oh joy. o Careful insulation required, otherwise heating bills will skyrocket as you try to heat up the surrounding earth.
Cheers,
Sid
Mmm. excavating foundations wasn;t that hard here..
I had considered that you would put that back on top...
Mmm. Thats a good point isn;t it?
Not with huger sewers ^H^H^H^H^H roads underneath...;-)
OK. lets look at it another way. Suppose you took a blockwork house and simply covered it over with soil? I accept the construction would need to be a bit more robust than for a plastic roof tile..e.g. prefab concrete beams..and a DPM all round etc..but drainage is not an issue provided that there is somewhere lower to drain TO.
I am thinking of a half cylinder made of say prestressed beams - like a tube tunnel - that stands weight well. All drainage is down the tunnel base, and the think has natural air ventilation with hot steamy air suing to a stack and heat exchanger and cool air being drawn in.. Light pipes for natural lighting...even a big periscope for a 'picture window'
You could grow anything on top of it - nice and carbon negative that..even fuel. Or collect water and so on.
The house would more be 'covered in soil' than 'below ground'
I like that. No external finish at all is there? No DG windows, woodwork and paintwork.. Access to 'ground' level might be an issue with stopping water ingress down the inevitable ramp..cattle grid and drain at the base?
You would certainly save on heating costs as the ground temp a couple of metres down is pretty constant. In fact with all the latest gov. ideas in underground thermal storage, it may not need any at all john2
First of all thanks for contributing some excellent points.
They said the same of tower blocks too..
Now, lets get detailed on that.
Does it need to be stronger? Some yes obviously, but I am not thinking of a house 400 foopt down,. just 4 ft down..maintaining enough topsoil to have an insulating and organic production layer above. Plenty of roof gardens are built on unamplifed structures..
Soundproofing. Yes. I accept that, but the roads would be deeper underground, and nothing proofs as well as soil IME..vibration, not sound would, I suspect,. be a greater issue.
Drainage is not an issue..as long as there is somewhere deeper to drain TO - and there would be - this is 'cut and cover' not tunnelling - I dio not see a huge problem.
Climate control I feel is easy. 4ft of soil is going to be a damn good insulator and a fairly massive block or concrete structure will equalize temperatures hugely.
Heat exchangers and judicious use of insulation OUTSIDE the structure..so that its both protected from soil movement and retains good thermal mass inside - should make it almost free of heating needs at all. Compared with the copious amounts of celotex and rockwool,. 4ft of earth on a polystyrene block is cheap..
Fire escapes are definititely an issue, however climbing up a flight of stairs rather than jumnping out of a window is no worse..
That was never the intention. I envisaged say 6ft tall pipes with galss tops..above 'peering' height for provacy..
And maybe perisocopes. Also top plant trees on top for further climate control.
Is it? Most people today spend more time peering into a TV/PC screen than out of the window, and in an urban environment I have never ever had a room with a decent view outside of extremeley expensive hotels and apartments I have visited.
I disagree with the 'vastly' bit. All roads need some earth moving, and a road in a cutting is more a problem because the spoils have to be physically removed..the further they have to go the worse it is. In this case however one is talking about digging a trench for the access roads and the services and then piling the material on top of the houses. Not very expensive at all..cut and cocver tunneling is far less expensive than real tunneling - where every cubic cm of spoil has to be removed out of the whole current tunnel length.
My vision is that the surface is the place where cyclists and pedestrians and dogs go, and trees and parks and so on. The houses are just underneath and the roads and shops are a bit deeper.
In the distant future, as populatoin
Yes..I just wanted to identify the costs and major technical problems with this.
The fact is that major city right now pours billions of megawatt hours into the sky and general environment. Putting a city underground would reduce all of that..any stray heat from streetlights would be trapped within the complex and contribute to warmer living space etc, as would proper heat exchangers on e.g. exhaust fumes..a climate controlled CITY with an eco area on top seems to me to be almost a no brainer..
Heck, you could build one on Mars...;-)
I am not so sure the costs are as prohibitive as you might think.
However there would be extreme issues with making it a small scale build. It has to be done on a whole neighborhood, or by a wealthy individual as a quirky 'grand design'..what a Phd project for an architecture graduate in conjunction with a civil engineer..design and cost an underground city..
I'm not sure about that - if you fully cover the ground with housing, that is a 3x increase, add 2 storeys below a two storey upper, that is a further 2x increase - 6x in total?
Much more economically achieved with basement parking, semi-basement apartments with "area" access and steps up to the ground floor, and of course medium and high-rise building. All achievable at lower cost than the large-scale construction of tunnels. Unfortunately much of that is now illegal for new build because of Part M requirements for disabled people. Fire regulations (which are a Good Thing, of course) make constructing new houses of 3 storeys more difficult.
Also it would be unpopular with many people - very few people want to live in even a fabulous detached modernist house in spacious private grounds, they would rather have tiny semis that look like 1930s metroland shrunk in the wash. Especially in England, they will not even buy flats unless nothing else is available. (A large part of this of course is the appalling English system of leasehold.) Spec builders will build what they can sell quickly at lowest cost, nothing innovative. Everybody buys houses with the "utility room" off the kitchen, so all the clothes and linens get carried down from the bedrooms upstairs, washed and dried, then carried back upstairs again. The house with an upstairs laundry-room or even a laundry chute is a rarity, even though with modern washing machines putting the laundry room next to rooms little-used during the day would not be a noise issue.
If new houses could be constructed with a basement, and a third floor in the attic, they could provide significantly better quality of living space in a smaller ground footprint. Compact residential areas, designated car-free, intermingled with commercial districts would allow many more people to walk to work.
However building new houses in Southern England is not the answer. It only encourages more people to live in the area, increasing the demand for schools, hospitals, etc, which in turn increases the demand for teachers, nurses, etc, who all need housing too. The only way is for the SE to have a major recession and house price crash, with jobs and investment moving to less populated areas of the UK.
Owain
I can't help thinking of David Essex as the Artilleryman in War of the Worlds
We'll build shops and hospitals and barracks right under their noses - right under their feet! Everything we need - banks, prisons and schools... We'll send scouting parties to collect books and stuff, and men like you'll teach the kids. Not poems and rubbish - science, so we can get everything working. We'll build villages and towns and... and... we'll play each other at cricket!
Covered. Noit a serious issue i think..designed right=no problem.
That is a good one I hadn't thought of.
Hmm. Down to effective ventilation and monitoring then.
No..my solutiuon was to cut and cover and raise the average ground level by say 50%..as long as the water course retained their places - usually at valley floors - no problem with rainwater. Sewage is simply a matter of running te sewers lower than the houses - as is done in london anyway under the embankment - and puumping up to the works...thats standard practice in any low lying aresa.
I think you should think that one through..carefully..I would say that heat and moisture buildup, not cold, is the problem.
Been on the tube lately?
I've mislaid my building regs, but IIRC a meter of rock is about the same as 50mm of celotex..and so I guess 4 ft of soil would be somewhat better.
No: getting it cool and dry and ventilated would be the problems - not heating.
The message from snipped-for-privacy@care2.com contains these words:
Or, if you fancy a grand scheme, try this one from 1931...
Not quite. The average depths of sewers will be lower, so cost more to fault find later. inital installation may well be the same as now, if you are cut-and-covering.
Of course, it depends how deep you go - far enough down and the rock is molten! However, at reasonable depths, the temperature is relatively constant, and lower than the standard 18-25 degrees centigrade many people are most comfortable at. Humidity will be a problem, although ventilation will help.
The earth does have large thermal inertia, so to start of with, moisture will condense on the walls like crazy, unless ventilation is adequate. After lots of heat input, the walls (and floor, and roof) will have heated up to a comfortable temperature. The problem then is to avoid overheating (like the underground, as you say). A lot of this is climate dependant - in a hot, dry, climate massive walls and sunken homes are an advantage. In a cold, wet, climate, a layer of sodden earth at between zero and 10 degrees centigrade against the walls of your dwelling makes it No Fun At All. Hence, decent isolation/insulation is required, otherwise you will be trying to heat the groundwater. You'll be looking at needing cavity walls, floor and ceiling - not a bad idea for drainage anyway - increasing construction costs. You'll need to ensure the drainage does not get blocked, otherwise the cavity will become a nice cold water jacket. Allowing for reasonable access for this will start to get expensive. Most of the water in the UK is hard water, so the drainage cavity will start to fill up with limescale deposits - even more fun to get rid of.
Cheers,
Sid
On 14 Sep 2006 07:17:28 -0700, snipped-for-privacy@mail.com wrote: | Most of the |water in the UK is hard water, so the drainage cavity will start to |fill up with limescale deposits - even more fun to get rid of.
Only in the dry South and East. In the wet North and West water is soft. Whichever a good cavity will be a must.
Some practical economics of getting it to work:
Greenfield sites are cheaper to build on than brownfield.
Flat land is cheaper to build on than not.
Low water table/low susceptability to flooding is good.
Moderately dense, well drained stony/gravelly soils is probably best (sand requires too much proping of excavations, clay is unstable, rock requires blasting and may trap water)
In city areas it would be more difficult to acheive compatability with existing services and flood drainage as well as having a large enough site to be economic.
Ideal would be an edge of town site for a new estate - somewhere where there's a well-heeled population to support higher costs, and somewhere with current overpopulation problems e.g Cambridge.
Better still if you can get greenbelt land on the basis that the development will be largely hidden from view. e.g. Cambridge - North of the A14
Given all the above, a cut-and-shut earth sheltered housing estate might be economically feasable - especially if you can get a bit of government assistance to pioneer it.
Gas, oil or solid fuel heating is probably out - unless it's open one side, earth sheltered rather then underground houses. That said, passive houses (no additional heating required) may be possible.
Underground roads require lots of forced ventilation. Underground fires/vehicle accidents are a special hazard. Probably not worth the cost as yet. Underground parking ramps would be a particular flood-route hazard.
Whatever you do - you MUST get the nod from mortgage and home insurance companies - without that, you'll struggle to sell any of them.
There's a need for continuous electrcity supply to run forced ventilation - possibly battery backed for power cuts.
You would probably need to include an insurance-backed warranty that the properties will be dampfree.
You might need to offer a guaranteed buy-back price to inspire consumer confidence.
AIUI earth sheltered/underground housing - the concrete has to be thick
- as the soil backfill will sink and apply greater and greater pressureover the years.
To keep concrete quantities reasonable, casting concrete against the exacavation wall (and one sided shuttering) is undesirable as the quantities are significantly increased. So double sided shuttering is prefered, but does require a lot of proping if there's no convenient pit walls to brace against.
Earth sheltered has the advantage of solar gain - and with good design, the concrete mass to act as a thermal store.
Finally you will need a local authority that's keen to support the project, and a developer willing to take an unknown financial risk - when there's probably plenty of safer investments about.
The tube is heated by all the traction motors of the trains. The tunnel air continuously flushed through by the trains themselves.
As a reference have a google for the cave houses in spain, around the town of Guadix. Briefly, they are dug out of the local soft rock (shale) and have walls *at least* 5 feet thick. A lot of them are over 100 years old and are still "standing". The first thing you notice is the quiet - there's literally no noise except that made by people/appliances in the house. A lot of people find that too spooky, or claustrophobic. They also tend to have much narrower temperature swings: staying cooler in summer (even in Andalucia, where outside temps. hit 40+) and very well insulated in winter.
Pete
Also the town of Coober Pedy in Australia;
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