7 Comments

Could a whole new lightweight structural approach become feasible with industrialisation? Early cars were built much like horse drawn carriages in some senses, but as tools and components evolved in tandem over decades we can now see stamped aluminium chassis which were inconceivable once, yet are capable of travelling at hundreds of miles per hour, turning corners, remaining watertight etc.

Cover seems to be experimenting with a stamped metal system. It would be nice to think the future still holds one or two huge leaps forward in building technology!

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I see how cheap water is per cubic foot, and I can't help but wonder if it could be used as a building material somehow? Surely, someone's already thought of this, and there's probably many problems with it, but if you want to just add mass to a building, water seems to be the cheapest thing just in terms of bulk costs. There's an article on ice architecture here https://www.architectmagazine.com/technology/the-future-of-ice-architecture_s - "reinforced ice construction" is a phrase I'd never thought I'd see - and here's one on where the walls are made of water curtains, though that's probably less applicable: https://sap.mit.edu/article/standard/building-made-water

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Brian, thanks for pointing out how the qualitative effects of material influence construction decisions. On that note, don't get too optimistic about cold formed metal framing---it's been around for nearly 100 years and dominates interior partitions for commercial buildings. It's possible to build exterior walls with it and avoid supplementary structure, but it requires exterior insulation to achieve optimal (and code required) thermal performance.

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founding

There are 7.5 gallons in a cubic foot so water should be priced at $0.02 per cubic foot, not $2.00 per cubic foot.

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I'm not entirely convinced by the cost-volume argument. Take a simplified model for a 2000 square ft = 185 sq m house, conceptualized as a cube with a 8m side. The cube has 6 faces of 64 sq.m each, and 2 interior floors, for a total of 512 square meters of structural walls.

Assuming walls are 35cm thick and made from a 50% combination of concrete and 50% polystyrene foam on average, the structure and thermal insulation of the house will require 180 cubic meters of material, which I'm going to round up to 250 cubic meters to account for foundation, interior walls, stairs etc., or 9000 cubic feet.

So the TOTAL volumetric cost for the main building materials is $27.000 (with your stated prices $4.5/foot of concrete and $1.5/foot of polystyrene). This covers structure, foundation, roof, interior walls, drywalling or equivalent, siding, waterproofing and any other cheap, bulk material.

$27.000 in bulk materials sounds excelent, a "3d printer" type of contraption that could magically arrange the concrete, foam and other cheap materials into the desired shape, function, aspect and performance has room to dramatically reduce total building costs. Sure, not all houses are cubes and not everyone wants a concrete roof, but as you say, that's already in the realm of tradeoffs rather than being a fundamental cost barrier for low cost building.

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