Housing Costs & 3-D Printed Houses

All the different ways of solving the shelter problem. To be static or mobile? Roots, legs, or wheels?
Western Red Cedar
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Housing Costs & 3-D Printed Houses

Post by Western Red Cedar »

Technological innovations changed many industries over the last 50-100 years - journalism, transportation, traditional commerce, etc. Housing and construction are arguably much less affected. Some new technology, like cross-laminated timber seem to be infiltrating the traditional design and construction process, but the process for building a house doesn't seem radically different from 50-60 years ago. As labor and materials increase in value, this leads to higher and higher housing prices.

I think Robert Shiller said a healthy housing market has a median cost to income ratio of 3. A median household income of $100k would support median values of $300k. I recently read that the ratio in New Zealand is 7. I think the Australian market is extremely high as well.

Questions for discussion:

Is the US heading in the same direction?
Do 3-D printed houses offer a way to upend the housing/residential construction business?
Are there other technologies to limit the dramatic rise in housing?
Or is the current market just the result of cheap money and fear of missing out?
Last edited by Western Red Cedar on Fri Aug 20, 2021 1:58 pm, edited 1 time in total.

AxelHeyst
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Re: Hosing Costs & 3-D Printed Houses

Post by AxelHeyst »

Buildings are one of the most legally constrained "technology spaces" there is, with proscriptive building codes that typically only change to get more proscriptive. A major reason you don't see much significant innovation in buildings is because it is literally illegal to do so.

Also, beyond legal constraints, the risk is high. A bug in an app annoys customers and can be fixed overnight. A bug in an innovative structural approach kills a family of six, financially destroys the firm responsible for the design, and possibly sees people doing time (worst case, obviously). (Berkebile is in my professional lineage).

Even my old industry, HVAC, managed to kill a bunch of people once, which you wouldn't expect from an industry that just keeps people cool, warm, and ventilated.

So, building codes and risk are two major major negative feedback loops in terms of innovation in the built environment.

And the style of construction that is generally accepted "bakes" in a certain level of complexity and cost to buildings. California is doing things like mandating solar panels which drives the cost of new construction even higher. There are a lot of minimum square footage regulations that require homes to be >x sf, which obviously keeps costs higher.

As with many things, we certainly can build inexpensive homes, it's just that most people's hands are tied. In short, "all" we need to do are:

Build smaller homes (reduce SF)
Build simpler homes (reduce $/SF)
Build homes appropriate to their climate (reduce the amount of expensive equipment needed to heat/cool/etc the homes).
Retrofit instead of build new (we probably have more than enough sf under roofs, we're just not using it very well).

Also, I don't understand this very well, but a large part of housing prices is demand. Houses cost a lot in SF because more people want them than have them available to sell. Rapid retrofitting would help with this.

In my opinion, from a technology perspective, beyond the regulation, risk, and demand issues, costs are going up because we're using too much technology and not enough brains. I don't think throwing more technology at housing is going to help much, and I don't think 3d printing has a bright future (homes are multi-material complex assemblies, which doesn't play to the strengths of 3d printing). Homes aren't rocket science, but people keep wanting to turn them into rockets. You need to keep the rain and critters out, be able to manage heat and moisture, ventilate it, and make it comfortable. It's not actually that difficult... it's just illegal to do it anyway except The Way It's Done.

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Re: Housing Costs & 3-D Printed Houses

Post by unemployable »

Axel hits most of the major points. One issue is that homeowners function as America's largest special-interest group (about two-thirds of all households). Once they get their house they become gatekeepers and resist any action that may lower the price of it, which on some level includes new construction. The obvious solutions -- relaxing codes, building more modular or mobile homes, allowing one to live in a vehicle on one's own property -- are either socially stigmatized, highly circumscribed or flat out made illegal. Housing is probably the one marketplace that seems the freest but is in fact the most proscribed and interfered with, and I don't see that changing much on the whole.

Note modular construction is ubiquitous with some types of buildings such as hotels, and to a lesser extent apartments and condos. No one worries about staying in a modular Courtyard -- hell most people don't even know. But somehow living in a modular house makes you second-class.

Three-D printed houses may become a niche market at some point, but it's really in its infancy and I doubt it would move the needle much. They''re subject to the same barriers and biases the other solutions are. Housing mostly prices off the ability to pay the monthly payment, and in turn, the extent to which people are willing to stretch their budgets to live in a certain place. A 1br apartment in Aspen is 5x one in Akron for a good reason, and for a 2000 ft^2 house the difference is more like 30x.

sky
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Re: Housing Costs & 3-D Printed Houses

Post by sky »

The current 3d printed houses seem to be made of a line of cement/concrete drawn into patterns to make walls. This is a very crude method of building. Eventually there will be houses built over forms using a composite method, for example, wrap the form in a plastic cloth coated with wet cement, cover it with construction foam, add a few more layers of plastic cloth and cement, deflate the inner form, then finish up with an inner and outer stucco coating. The automation part of it will be a way to move rolls of fabric across the building to lay fabric down in the right place while spraying it with cement. It shouldn't be too hard, set up three or more cranes and use cables and computer controlled winches to move the fabric rolls and cement sprayers.

AxelHeyst
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Re: Housing Costs & 3-D Printed Houses

Post by AxelHeyst »

If I had to put money on cost-reduction innovation in the built environment, it’d actually be pre-fab. Don’t think “mobile home”, think “how they make cars” - in the controlled environment of a factory, where they can apply a century’s worth of automation and process engineering to the production of complex assemblies. One of the reasons homes are expensive is because so many of them are one-offs, requiring custom design and construction for each one. If they built cars that way every car would cost 100’s of thousands of dollars. And don’t imagine a fully built home rolling out of a factory, think of a flatbed full of manufactured “parts” that just have to be more or less bolted together on site. They’re doing this more with commercial buildings (you can watch timelapses of high rises in Asia going up in a couple days), I assume they’ll start doing it more with homes once they get the hang of it.

horsewoman
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Re: Housing Costs & 3-D Printed Houses

Post by horsewoman »

That's how a typical *Fertighaus" (ready-made house) in Germany is built - which are most of new houses these days. There is a concrete slab poured on the ground as a base, and after this has dried out a few trucks from the factory with parts and a crane arrives. My friends house was erected in 3 days. Afterwards a crew did all plumbing and wiring in a few days. These houses still cost several 100k Euros and have the charm of shoe boxes.
the building laws in Germany are even more extreme than those in the US, I assume
Germans do like rules and regulations :)

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Re: Housing Costs & 3-D Printed Houses

Post by unemployable »

AxelHeyst wrote:
Sat Aug 21, 2021 3:18 pm
If I had to put money on cost-reduction innovation in the built environment, it’d actually be pre-fab. Don’t think “mobile home”, think “how they make cars” - in the controlled environment of a factory, where they can apply a century’s worth of automation and process engineering to the production of complex assemblies.
That's modular and it's done already, although granted, currently has a small share of the single family residence market.

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Re: Housing Costs & 3-D Printed Houses

Post by rube »

Prices are mainly up by two parts
1: cost of building (construction), i.e. labour and material (and permits and stuff)
2: plot (location).
#1 is pretty fixed based on the type of house, construction method etc. You can shave off a bit and there but it is relatively limited and within a certain price range per square meter / foot.
#2 is the result of what people are able to pay (low interest) and supply-demand minus #1. Also known as residual land value.
https://www.efinancialmodels.com/knowle ... -calculate

In high demand places and a low interest environment, the prices for plots (location) is shooting up. Even if you're able to come up with a cheaper building technique/house style, it probably means that the price which people are willing to pay stays the same and so the value of the land goes up.

Only for locations where there is no high demand, the price of the plots are (much) lower. Here you can influence the total cost (and price) (much) more by cheaper constructions.

I used to look to make a cob-, strawbale building, earthship house myself: the construction materials of such houses are relatively/very cheap and it is easier to do a lot by yourself. So the construction cost is cheaper.
But I found out that when you add the costs for the land, the permits, and a few other difficult to avoid costs, the construction cost (at least in the area we looked) came "only" at out about ~40% of the total costs. The "savings" by doing a lot yourself and choosing an alternative method is likely limited to a 50% of the total construction costs, so it would "only" save 20% of the total costs compared to a more traditional home build by others.

But if land is cheap and you can build "differently" yourself it can be much cheaper. I don't know what @theanimal spend on his house, but it is probably a fraction compared to house prices of the same square footage in the bay area.

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Re: Housing Costs & 3-D Printed Houses

Post by 7Wannabe5 »

I think “shelter” conveys “something like a roof” as most minimal design to most modern humans, but “something like a hearth” would actually be most minimal design of “home.” Therefore, the easiest, most efficient way to reduce housing costs in populous area (almost everywhere now since we are down to 2 acres per human) that require safety codes would be to increase the number of humans per kitchen/furnace/electrical outlet. If you think about it, electrical outlets are kind of like the hearths for all of our “energy slaves.”

Western Red Cedar
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Re: Housing Costs & 3-D Printed Houses

Post by Western Red Cedar »

I forgot about this thread and then saw this video from Kirsten Dirksen pop up on my YouTube thread. It hits on a lot of points I was thinking about. Namely that we are still building using antiquated technology and methods in the US. It also speaks to the issue of navigating strict building and land use codes. Of course, you have to take this with a grain of salt as it is coming from a small firm in the 3-D house printing business.

https://www.youtube.com/watch?v=TxO46yjE8dI

I agree with most of what everyone said upthread. I think the one major factor missing from @AH's analysis is the financial component of building and developing. Some of this is tied to codes of course, but some of the problem is that banks are risk-averse and don't want to lend money to new methods. They like models that have made money in the past. Those tend to be larger houses, developed on greenfields.

One of the major reasons developers aren't building smaller houses is that they have a higher profit margin with more sf. It is the same reason why american car manufacturers are making a lot of $65,000 trucks, rather than small, compact, fuel efficient cars. There is a certain upfront cost with the labor and material, and larger, more expensive products provide a higher profit.

@rube - Interesting link! Thanks for posting that. I hadn't seen the financials broken down quite like that.

ETA - I had mostly focused on housing costs in my initial post, but the video also talks a lot about the environmental rationale for moving towards 3-D printing in residential construction.

oldbeyond
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Re: Housing Costs & 3-D Printed Houses

Post by oldbeyond »

It’s hard to achieve economies of scale in construction (to do so you end up with cookie cutter suburbia or Soviet apartment blocks, and even then landscape/utilities/wind/solar exposure/soil etc won’t be uniform). It’s extremely capital intensive, location bound, and the invasiveness of the process and the result, the high risks (structural, fire, health and safety) as well as the long time scales involved (construction taking years and the finished structure standing for decades) invites a lot of regulation. Basically it has a lof of features that do not play to the strengths of global capitalism, compared to making gadgets.

But the real issue is the value of land. There are a lot of affordable housing and ample land in many countries, but not in the places where economic activity concentrates.

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Re: Housing Costs & 3-D Printed Houses

Post by oldbeyond »

Also there has been a major shift towards prefabrication (everything from concrete slabs to exterior walls to entire bathroom suites), to avoid work on site as much as possible, 3D-printing being one (high tech) version of that not much used as of yet.

Western Red Cedar
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Re: Housing Costs & 3-D Printed Houses

Post by Western Red Cedar »

oldbeyond wrote:
Wed Sep 22, 2021 12:52 pm
Also there has been a major shift towards prefabrication (everything from concrete slabs to exterior walls to entire bathroom suites), to avoid work on site as much as possible, 3D-printing being one (high tech) version of that not much used as of yet.
Do you think the shift to prefab has actually affected costs much in the US? Will it in the future? I believe Europe is a decade or two ahead of the US on this front, at least in terms of CLT. Prefab seems to have gotten a bad reputation in the US due to some low-quality manufactured homes, but it seems like you can develop some pretty nice buildings with this approach.
oldbeyond wrote:
Wed Sep 22, 2021 12:46 pm
But the real issue is the value of land. There are a lot of affordable housing and ample land in many countries, but not in the places where economic activity concentrates.
I totally agree with this. One thing the causal observer may miss in places with high economic activity is the amount of infrastructure invested in these locations. Valuations will naturally increase when governments or business make massive investments in certain locations.

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Re: Housing Costs & 3-D Printed Houses

Post by oldbeyond »

Prefabrication is really a matter of degree, as you have to go way back in time to find people making doors or roof tiles on site for example. The dynamic is more one of prefabricating more than it being a wholly new concept. It does give you some of the productivity gains from the rest of the industrial production system, becoming more of a specialist and less of a generalist. The fundamental trade-off is the increased complexity and lessened understanding of the whole system. Doing things on site is less efficient but more resilient (managing errors, late revisions, supply errors, tolerancea etc). A high level of prefabrication places higher demands on the design process and the project management during construction. On the whole I think prefabrication has helped to depress costs, but other factors have pulled in the opposite direction (energy requirements, building codes, more tech embedded in buildings, health and safety standards). The push for specialization (prefabrication) will likely continue. There are quite a few players doing modular apartment buildings (prefabricating apartment modules, erecting a structure and then finishing off the exterior). Most likely the reduction in construction costs will be modest, and the reduction in project cost smaller still as per rube’s example.

Infrastructure certainly plays a part. The biggest factor I’d say is the sort of rockstar network effects you get in places like Silicon Valley or Manhattan. Also an example of specialization in action.

Frita
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Re: Housing Costs & 3-D Printed Houses

Post by Frita »

Check out Apple TV’s Home series’ year 1, episode 9: https://m.imdb.com/title/tt11639494/?ref_=tt_eps_top

What could happen if we would adopt a smaller footprint as seen in these all-you-need-sized homes?

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Re: Housing Costs & 3-D Printed Houses

Post by chenda »

The timber framed Huf Haus style design which @horsewomen mentioned are quite popular here. It comes on the back of a lorry from the factory in Germany, complete with German builders in toe who assemble it on site in just a few days. It's high quality build and very energy efficient, although it's not cheap and largely caters to a private affluent market. However, I believe in Germany the technology has been scaled up for multi-unit occupation and some social housing projects. I expect similar methods to be more common in both public and private residential construction in the future, as much for the assurance of speed, quality and regulatory compliance as anything else. As others have noted, the land price underpins much of the cost.

The main issue with timber framing (and I note there are other types of prefabricated building methods) may be you are probably limited to 4-6 stories. Beyond which you will likely need reinforced concrete framing, and the height limitations of timber framing may limit its cost effectiveness in high density urban areas. It would be interesting to compare the CO2 footprint of prefabricated timber construction and other building methods. Of course, converting and retrofitting existing buildings rather than new build will be much closer to carbon neutrality.

Another area where we may see more 3d manufacturing might be high end construction. If you look at lavish 18th and 19th century high end construction like the Beaux Art school in the Belle Epoque, you realise it simple wouldn't be remotely affordable to build those sort of buildings today. The labour costs and specialist skills required for such detailing and quality would be prohibitive even for the wealthest. 3D technology might see a return to such architectural detailing and design complexity.

oldbeyond
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Re: Housing Costs & 3-D Printed Houses

Post by oldbeyond »

Kit homes have a long history. You could order them through the Sears Catalog way back when: https://youtu.be/su3tYI78EGg

It’s an interesting hybrid between traditional (incremental, small-scale, family driven) development and industrialization. It seems like its era ended when large-scale institutionalized development became the norm.

oldbeyond
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Re: Housing Costs & 3-D Printed Houses

Post by oldbeyond »

@chenda: It’s possible to create hybrid structures where some concrete is used (core walls around the elevator/staircase or in some floors to increase mass) that are quite a bit higher. See Treet in Bergen, Norway for example: https://urbannext.net/treet/
(Built using a modular design for the apartments as well!).

They had to resort to trusses in the facade and outrigger floors as well, though. A concrete core would simplify things. From what I can gather, Treet was a proof of concept, so they might have been willing to push the envelope a bit.

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Re: Housing Costs & 3-D Printed Houses

Post by 7Wannabe5 »

You could pretty easily buy 5 fixer-uppers for $200,000 inclusive of land in my neck of the woods, because the population has declined by 20% over the last decade, and even more over the last 40 years. Of course, as an investment you'd have to be looking at long run global climate change potential buying depressed property over latitude 42 near plentiful fresh water and productive agricultural/woodlands. There's an entire abandoned going-back-to-nature urban mobile home court across the street from my property.

Western Red Cedar
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Re: Housing Costs & 3-D Printed Houses

Post by Western Red Cedar »

chenda wrote:
Thu Sep 23, 2021 9:31 am
The main issue with timber framing (and I note there are other types of prefabricated building methods) may be you are probably limited to 4-6 stories. Beyond which you will likely need reinforced concrete framing, and the height limitations of timber framing may limit its cost effectiveness in high density urban areas. It would be interesting to compare the CO2 footprint of prefabricated timber construction and other building methods. Of course, converting and retrofitting existing buildings rather than new build will be much closer to carbon neutrality.
They are working on going taller :) :

https://www.youtube.com/watch?v=2DPp2NcnTb0

https://www.youtube.com/watch?v=Xi_PD5aZT7Q

One of the environmental benefits of prefabricated timber is carbon sequestration. In the Pacific Northwest, they've also been able to use much smaller trees which, at least in theory, can lead to more sustainable forest management.

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