
Mighty Buildings (YC W18) can 3D-print houses, even the roof - jseliger
https://www.fastcompany.com/90534917/these-cute-backyard-houses-are-entirely-3d-printed
======
syedkarim
"350-square-foot studio, starting at $115,000"

$330/square foot is not cheap.

I live in a prefab home that was trailered in and placed on the basement with
a crane. I visited the factory in Indiana, which was basically a lot of
carpenters building homes inside of a warehouse.

[https://www.rochesterhomesinc.com/tiptown](https://www.rochesterhomesinc.com/tiptown)

My house is 1568 square feet and looks almost exactly like the picture on the
website. The price from Rochester was $120,000. From the factory, the house
was almost completely finished (drywall, bathroom, cabinets, etc).
Carpeting/flooring was done after the house was delivered, as well as some
customizations and modifications for code (sprinkler system).

$77/square foot.

There are tons of other costs with building a house on vacant land, but those
are the same regardless of how the house is constructed.

Mighty Homes has some really interesting technology, but there is definitely a
premium to be paid for it. It's really, really hard to beat the economics of
stick-built construction. At least right now.

~~~
walrus01
One of the problems I ran into when researching 'manufactured homes' is that
it's difficult to distinguish from the marketing materials, the homes which
are built from the cheapest possible lumber, particleboard, MDF and chipboard.
Such as:
[https://en.wikipedia.org/wiki/Clayton_Homes](https://en.wikipedia.org/wiki/Clayton_Homes)

And those which are built to a higher quality standard, indoors in a factory
as you describe, but are not something that will begin falling apart after
5-10 years.

Unfortunately in many parts of the US and Canada any 'manufactured home' may
be prohibited by zoning laws, because cities don't want more trailer parks.
And they can be totally ineligible for the same rates of mortgage as a home
built on site.

~~~
syedkarim
The term you are looking for is modular home—a house that comes in pieces and
is finished on site, though smaller modular homes can be just a single piece.
The big difference between the two is modular homes are put on a foundation,
whereas manufactured (previously called mobile homes) housing is built on a
frame that has temporary axles. If a manufactured house is set on a
foundation, it might not be considered a manufactured home anymore.

The quality of the build can be good or bad for either type, though cheaper
materials tend to get used in manufactured homes since cost is usually the
driver on those homes.

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Animats
_The homes are made of Light Stone, a thermoset composite material that
hardens when exposed to UV light._ \- Mighty Buildings.

The material used is more interesting than making prefab houses this way. Lots
of companies make prefab houses, many of which are better and cheaper than
these. Being able to 3D print big, weatherproof parts is useful in itself.

"Light Stone" appears to be a name used by Mad Maker Filament for NatureWorks
3D870.[1] It's high-temperature PLA (polylactic acid), a better version of the
plastic used with 3D filament printers. I'm puzzled at the use of UV lighting.
That's not something normally done with PLA, but it's not unknown. Also, PLA
is a thermoplastic (melts and re-hardens to the same form) as opposed to a
thermosetting plastic (changes molecular structure when heated.) Did they find
something that can be heated to make it soft, put in place, and then hit with
UV to crosslink the strands, like the plastics used for dental fillings?

[1] [https://www.natureworksllc.com/Products/3D-series-
for-3D-pri...](https://www.natureworksllc.com/Products/3D-series-
for-3D-printing)

~~~
tootie
I was surprised by that too. All the human-scale 3D printed construction I've
seen before used some form of concrete and not polymer.

~~~
Animats
3D printing in concrete remains more a curiosity and artistic device than a
useful way to make strong concrete objects. There's no compaction.

Compare the Lil Bubba Curb Machine.[1] This is a simple slip-form device for
making road curbs and such. You pour in concrete, and it pushes itself along
by pushing concrete into the slip form. The concrete is compacted by the push,
and a smooth curb emerges from the output end of the form.

Somebody should combine pumped concrete 3D printing with a compacting device
like the Lil Bubba. Then you could get smooth surfaces, not things that look
like stacked layers of toothpaste.

[1] [https://youtu.be/NJZMpu4MKn8](https://youtu.be/NJZMpu4MKn8)

------
elihu
> The startup, which launched from stealth today and graduated from Y
> Combinator’s tech accelerator in 2018, developed a synthetic, lightweight
> stone material similar to Corian, a material sometimes used in countertops.
> As the material is printed and exposed to light, it creates a reaction that
> immediately hardens it. “It literally freezes in air,” says Solonitsyn. It
> can support its own weight, making it possible to print horizontally in the
> air.

This seems like the most interesting part; they're using a new material rather
than just coming up with a new kind of 3D printer. The obvious follow-up
questions are whether it's cheap enough, or strong enough, or environmentally
sustainable to manufacture on a huge scale, and whether the material has a
long usable lifetime and doesn't have flammability issues or off-gas any
unpleasant chemicals.

------
simonebrunozzi
> Correction: We’ve updated this article to clarify that the units currently
> under construction by Mighty Buildings are not entirely 3D-printed, but the
> next iteration will be.

Very important correction.

~~~
tintor
Fake it, 'till you make it.

------
elihu
I think that an important missing piece in realizing the full benefit of
machines that print houses is software that does automated building design.

The way most suburban residential construction is done these days (at least in
the U.S.) is to start with a large area, split it up into relatively
homogeneous lots, and flatten them out as much as possible so that they fit
the requirements of one of some set of floor plans that were designed without
regard for any specific lot.

The alternative to this is to do custom designs that take the considerations
of particular lots into consideration, like the position of the sun during the
day, the direction of the best views, layout of the yard, etc.. This is
expensive and hard to do on a large scale, because you can't amortize the cost
of the architect over multiple buildings.

Another alternative is to have a software package that takes a given lot and
generates a floorplan optimized for that lot (and the needs of the buyer, if
known). This is a hard problem, but I think it gets easier, or at least more
interesting, when combined with machines that can build houses. With 3D
printing, the design can be as complicated as you want, with little impact on
cost. You can have funny-shaped walls that aren't at right angles with each
other, vaulted ceilings, gothic arches, flying buttresses, or any kind of
ornamentation or functional feature without regard for having to consider the
difficulty of expressing the design to human workers. If done well, it could
be a major step forward for well-designed residential construction -- you get
a custom building on every lot that's optimized to match the site rather than
forcing the site to match the builder's requirements, and the marginal cost of
the design work is low (probably more than zero, since you'd need a human to
review the design and possibly negotiate with customers).

~~~
lazyasciiart
> You can have funny-shaped walls that aren't at right angles with each other,
> vaulted ceilings, gothic arches, flying buttresses, or any kind of
> ornamentation or functional feature

You're going to have to allow for a _lot_ more negotiation with customers once
you start adding "frills" \- one reason that houses built in bulk are so plain
is that tastes vary hugely and you have to bet on what flavor is going to be
popular right when you want to sell them all. Flourishes are the kind of thing
that will rarely make a sale but will easily break it.

~~~
elihu
Sure, but if one were to design the software to construct houses in a
distinctive style that a lot of people like, then it probably won't be too
hard to find people willing to buy.

Part of the developer's "brand" could be to invent new and interesting styles
without getting too carried away with ornamentation for its own sake, or
adding features that most people don't want.

Flying buttresses and gothic arches were kind of a silly example; probably
most houses wouldn't benefit from looking like Notre Dame (especially if
everyone started building their houses to look that way), but there may be
other styles that would look nice and would fit well into their environment,
but which wouldn't catch on now because it's too complex and therefore too
expensive to build.

~~~
notahacker
It's not difficulty in planning that's responsible for the ubiquitous right
angle, it's the tendency of people to like familiar features and want their
furniture to fit (they're also often fond of materials not particularly
amenable to 3D printing). Architects would love to design the sort of
curvaceous things from concrete, steel and glass they went to architecture
school to admire, but the need to sell the houses gets in the way.

I'm struggling to see procedural generation of the designs as doing anything
but subtract from the ability to conceive 'distinctive style a lot of people
like', given that architects _are_ people with likes, can talk to prospective
purchasers about their likes and understand at a high level how people might
use [or not use] particular design features and what designs regulators might
reject.

Neural networks, on the other hand, produce outputs which are just a function
of their inputs. Procedural building generation is what designers of 3D worlds
use for the bits whose appearance they _don 't_ care enough about to detail by
hand. The one place software design might lead to improved efficiency is
randomising features for McMansions on a street from a simple library of
squares and automatically generating the docs...

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djrogers
> Compared to an average house in California, the new homes cost as much as
> 45% less.

> The company is making homes in a variety of sizes, ranging from a
> 350-square-foot studio (starting at $115,000,

These two statements do not compute. I’m in the process of planning an ADU,
and $115k for 350sq ft is smack dab in the middle of the ‘really nice’ prefab
ADUs in the Bay Area, and as much as 50% higher than the less expensive
options.

If these truly were cheaper, I’d be willing to take a risk on it.

~~~
titanomachy
Probably, they are taking the average over all homes built rather than just
prefabs.

------
robomartin
I would be interested in learning more about how it is that YC accepts a
company like this into the program, which, by definition, excludes others.

I place 3D printed homes right up there with flying cars. It makes for great
futuristic articles, sure, yet, outside of corner cases _nobody_ wants or
needs a 3D printed house or a flying car. One could make an argument that
these are places where dollar bills go to die and will be so for twenty-five
years or more.

I am puzzled because of notions such as product-market fit, traction, and
“build something people want”.

Outside of that, anyone with experience in construction can rattle-off at
least a dozen ways for which a 3D printed home could be undesirable.

Even better, anyone with experience dealing with construction regulatory
bodies (Building and Permit, inspections, zoning, planning, fire) knows full-
well how much of a surreal nightmare this can become.

As a simple example, LA County Building and Permit added six months and at
least $50K to my solar energy project simply because it didn’t fit within
checkboxes the people I was dealing with were used to. Trying to introduce
materials not on the approved lists could take decades and millions of
dollars. I learned more about this than I care to admit.

So. Yeah. Why?

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JoeAltmaier
Isn't a large part of house building, installing the plumbing and electrics?
Is this handled by 3D printing? Or is it just the framing that is accelerated?

I'm thinking this may be a more expensive prefab approach, and may not be
better than current approaches.

------
jseliger
May dovetail with this story:
[https://news.ycombinator.com/item?id=24051907](https://news.ycombinator.com/item?id=24051907)

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thrill
Very nice. Having worked in home construction weekends and summers to pay for
about half of my college, any technology that can reduce the labor and time to
build homes, especially if it's cheaper, is a winner.

