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.
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.
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?
from email@example.com contains these words:
Or, if you fancy a grand scheme, try this one from 1931...
Or this bloke from the 30s as well...
Pay no attention to that man behind the curtain.
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'
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
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.
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
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
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
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.
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.
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?
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.
On 14 Sep 2006 07:17:28 -0700, firstname.lastname@example.org 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.
Dave Fawthrop <dave hyphenologist co uk> Google Groups is IME the *worst*
method of accessing usenet. GG subscribers would be well advised get a
Aah! I see. Thank-you.
I agree completely that a 4 foot thickness of wet earth can potentially
be a good thermal store. How good it is as an insulator, I'm not sure.
I'm pretty certain a 4 foot thickness of dry earth would be better.
I'm sure someone (possibly even you) may have tables that include the
numbers comparing celotex, wet earth, dry earth, straw, concrete, you
name it. A quick Google gives:
"Dry materials are better insulators since water is a good conductor -
so dry insulation is better than wet insulation. That's especially
important with earth-insulated buildings.
Here are some very rough approximate r-values of materials per inch of
Dry earth: 0.33 per inch
Wet earth: 0.05 per inch
Wood: 1.25 per inch (assume the same for cardboard - not the corrugated
kind but solid cardboard)
Fiberglass insulation: 3.5 per inch
Styrofoam: 5.0 per inch (use packing material or cut up a Styrofoam
So in order to compare a house wall with 3 inches of fiberglass
insulation and 1/2 inch of plywood siding (total r-value of 11.125) to
the same r-value of earth-sheltering, you'd need about 36 inches of dry
earth. Once the earth wet, you'd need 222 inches (18 feet) to get the
The problem is that water tends to move through wet earth - having
heated the water up, it's difficult to guarantee that it will stay in
the same place, unless you take measures like enclosing the wet earth
in a water-tight membrane of some type. If it is not enclosed at the
top, heating it above ambient will mean you increase the evaporation
rate. Ground-water movement also means it will be replaced by cooler
water at varying rates depending on the environment. I'm not saying
you can't make it work, the point I was alluding to about needing
'decent isolation/insulation' was simply that you will have to take
As an afterthought, here's a page from CSIRO, admittedly talking about
My, tentative, conclusion is that you would want to use something other
than just plain in-situ earth as an insulator in a subterranean home -
possibly your 50mm of Celotex.
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