Thomas Edison's Concrete Houses | Hacker News Reader

Thomas Edison's Concrete Houses

atlasobscura.com

107 pointsadrian_mrd87 comments

Notable that the Edison houses aren't form-cast like we do today, which is just structural and rather rough; the concrete was meant to be the finished wall both interior and exterior, including the roof and all interior and exterior ornament. The forms were nickel-plated cast iron.

https://www.scientificamerican.com/article/edisons-system-of...

so hot in summer, cold in winter, best of both worlds :)

Uh, quite the opposite. Thermal mass is a thing.

How houses are built in Iceland: https://youtu.be/7RuTizbnH4s?si=JxRjqzVFy4NLg3wa

(Spoiler; we cast them from 1 foot thick concrete slabs)

"Thermal mass" and thick concrete isn't what keeps that house at a comfortable temperature from summer to winter.

It's comfortable for the same reason as any other house: because it has thick insulation both outside and inside the concrete. See @4:30 in your linked video.[0]

If you like, sit down and do the math for how thick concrete you'd need in order to store heat for 6+ months and average out the summer/winter temperature change. It's not 1 foot thick, it's more like 30 feet thick!!

In general, the effect of thermal mass tends to be strongly overrated by people who aren't experts in building science.[1]

[0] https://www.youtube.com/watch?v=7RuTizbnH4s&t=270

[1] https://web.archive.org/web/20130509032945/http://www.greenb...

Does anyone know where there are pictures of the interiors of these homes? I'm very curious about the concrete bath fixtures, but can't seem to find anything online that definitively shows the inside of an Edison concrete home. It's also interesting to see this in light of all the news recently about 3D printed concrete and how there are many of the same challenges now that Edison must have had to deal with then. Plumbing, electrical, insulation, and so forth all have to be incorporated into the design or tacked on afterward.

Check out some urban exploration videos https://youtu.be/-knB658OpC0

Insulating concrete form (ICF) is popular in some quarters:

* https://en.wikipedia.org/wiki/Insulating_concrete_form

Instead of setting up formwork [0] with rebar, pouring and curing concrete, and then spending time (=money) tearing things down, the formwork is an insulating foam that is left in place. One consideration is that you then have to put some paneling in front of it (on either/both interior and exterior faces).

Depending on the aesthetic you wish to have, you can have smooth concrete exposed or have textures, e.g., board-formed:

* https://www.youtube.com/watch?v=W1JLy8ZSH2Q

* https://www.youtube.com/watch?v=688MeG_RKRM

[0] https://en.wikipedia.org/wiki/Formwork

I built a 100'x60' 2 story building using these blocks with just me at age 20 and a 16 year old kid. Spent the days building lego brick wall and laying and tying rebar. Cement day was mostly a rest day watching the pump truck fill the section of wall. This is a fantastic construction method in many climates. The biggest downside of raw concrete structures is the lack of insulation.

Amazing! How did you learn this at age 20? Now I feel like a pathetic underachiever

On this job. Pretty much read the instructions and off to the races. The GC that hired me stuck around for a week or so to make sure everything was going smooth then he was off keeping the supplies flowing and would just check in every few days. The ease of building with ICF is a huge draw. It takes zero experience with concrete or building forms.

Learning something new every day. Thanks much for this.

Ironic because the technology is called insulated concrete forms. Newer ones are supposed to have an ok r value unless the older ones were much different. https://buildersontario.com/icf-r-value

Yes, I was saying that ICF fixes the problem of concrete not being insulated. Without insulation a concrete building feels like a cave.

My neighbour used the same technique to built his house here in Germany together with his wife. Their house know fullfils the requirements for one of the highest insulation standards here in Germany, called "Passive House". So I assume there must be great insulation materials available that can be attached to the outside of the walls.

there is a blogger that built a 'momplex' for her mother and mother in law in Alaska out of ICF forms, and she has some great blog posts on how they built it, the steps and work involved, as well as many plans and designs for the furniture, cabinets, etc, she built for inside the duplex. Her site is execellent for people interested in learning about woodworking, but the momplex series is facinating

* https://www.ana-white.com/woodworking-projects/maincategory/...

Ha, I've used a couple of her plans to build simple furniture. I didn't know about this backstory. Neat!

I was surprised to see a concrete pour below freezing temperatures. I'll have to read more about that.

The curing process is exothermic so it's possible the insulated forms keep enough of that heat in to make the process work even in the cold.

I once had to patch some broken pavement for insurance during mid December when it was 38 F out. After some research and speaking to a friend I covered the wet concrete with a trash bag and placed an old cargo blanket on top for insulation secured with a sheet of plywood weighted down with rocks. Cured just fine and ins agent was happy.

They do concrete work in Canada in freezing temps all the time. It just can't be "too cold" or even the insulation / heating isn't enough. But in general 38F is "laughable" so to speak ;) Seen them do it in sub 0 (C of course, it's Canada) all the time.

The Orlando Public Library is a little too brutalist for my taste, but is an interesting example of board-formed concrete:

https://en.wikipedia.org/wiki/Orange_County_Library_System#/...

Yeah a big downside of concrete construction seems to be that a significant proportion of builders/architects just say "fuck it, we'll leave the bare concrete exposed" and you end up with monstrosities like that.

They're not saying "fuck it", it's a deliberate aesthetic.

Not all bare concrete construction is a brutalist nightmare, look up Tadao Ando's work.

This is pretty much the first thing that came up when I searched for him:

https://lh3.googleusercontent.com/p/AF1QipPq8IzhBMH8PJBuKcVS...

ngl I think it looks pretty good. Way more visual interest than I expected

There's also some inversions of ICF where the insulating foam is on the inside and the concrete blocks are layers on the outside. OmniBlock is the manufacturer that I can remember but there may be others.

Not sure what the tradeoffs are but I'd assume two big pros are (1) concrete's easier to attach things to and (2) concrete can be directly finished both on the exterior and interior.

I'm not sure how people run electrical and other utility through these. And I'd expect that half the inspection / code in the US has no idea how to handle either ICF or related, but I'd love to be wrong.

The concrete houses reminded me of the George Eastman (founder of Eastman Kodak camera company) [estate](https://en.wikipedia.org/wiki/George_Eastman_Museum) which is now a museum in Rochester.

Built in 1905 of reinforced concrete.

Worth a visit.

You can still custom-build a concrete house today and put regular siding so it looks just like any other house. You can't tell it's concrete from the outside, but the house is a lot tougher - especially against hurricanes.

Prior to tech, I primary worked in construction during and right out of high school.

Cast-in-place concrete dwellings have never caught on despite it making a tremendous amount of economic sense. While it has a foothold in the market for specific applications (basements, retaining walls, commercial buildings, etc), a concrete house form in-a-box poses some logistical challenges and human ones.

First, the vision here was to be able to drop a form and creates a single pour/unibody structure (like injection molded plastic). That is very difficult to do and most concrete work is done in multiple stages for this reason. The main challenge is the creation a form that is sufficiently supported on the inside to create the “void” of the living space. You’re having, instead, to pour a slab, wait a sufficiently long time for it to cure enough to support weight, and do the walls and ceiling next.

The other logistical issue is internal reinforcement, which is what rebar is for. Concrete, as a building material, can really only resist compressive loads, which makes unaided concrete highly unsuitable for applications where there is a void underneath (in our home, for example, under a window frame, under a ceiling, or in infrastructure, as an overpass) However, by using iron-reinforced concrete, we can turn shear forces into compressive and by using pretensioned concrete (stretching of reinforcement cables prior to concrete pour), we turn tension into compression as those stretched steel wires want to return back to their original shape, it’s like an internal lasso keeping it together.

The last logistical challenge is installation of all utilities, which means in/under slab and wall piping (water supply lines, in floor heating, DWV, etc), electrical with conduit setup going to masonry boxes, outlets, switches, light fixtures.

The point here is, setting up for a concrete pour is not as simple as erecting forms. When the concrete pour is cured into a structure, it’s now a very inflexible material to work with and any wall penetration needs to be checked against blueprints, new electrical need to be run on the surface, leak repairs need to be done with very specialized equipment and a tunnel created under the dwelling, etc.

The other main problem is that people don’t want complete concrete homes. Without in-slab heating, it is a cold, hard, unforgiving material that allows for zero flexibility and repairs are a nightmare. Just like software, homes should be built with maintenance in mind because that’s the normal state in which it is worked on. Plus, it feels like a prison. At least it won’t burn down?

I have a lot of gripes with slab-on-grade construction[0] for this reason, and every dwelling I’ve built has had at least a crawl space, often a basement where everything is serviceable. The basement is usually CMU (concrete masonry units, aka cinder block), precast concrete (slabs trucked in), or, rarely, ICF (insulated concrete forms, basically in-place formwork with concrete in the middle of two pieces of foam insulation like an ice cream sandwich[1]).

I think there are some things we can learn from commercial buildings where you can have concrete skeletons[2][3] but large cut-outs where you can build walls. Inside the concrete pillars are PVC channels that let you thread wiring and plumbing, and other things through without having to do a concrete penetration. To built the house part, you effective put up wood frame walls in the voids or an aluminum-framed window installation (like a storefront assembly).

Side note: If you have ever wondered why you see basements in colder climates (and conversely more slab-on-grade in warmer ones) is because the bottom of your construction need to be situated under the frost line to prevent shifting caused by the ground freezing. So if you have to dig 4ft down anyway to reach that point, maybe just dig out a 5ft hole and install a basement instead, then your can have your home’s first/ground floor about 3-5 feet elevated. Slabs made to handle the shifting of ground due to freezing, liquefaction, or unstable building surfaces are called “rafts” and are not used very often compared to other methods.

[0]: https://anchorfoundationrepair.net/blog/slab-foundation-how-...

[1]: https://images.finehomebuilding.com/app/uploads/2017/10/3011...

[2]: https://en.m.wikipedia.org/wiki/Concrete_frame

[3]: https://www.understandconstruction.com/concrete-frame-struct...

Many thousands of these (perhaps 17k) were built in Dublin, Ireland from mid 1930s-40s. Poured/shuttered concrete and rebar, concrete floor at ground level, internal walls are block work.

I live in one -- recently had insulated externally (100mm EWI) which has drastically improved its thermal properties. About 50% of the floor area downstairs is the original bitumen sealed, uninsulated concrete. No ducts, you want extra wires or pipes you make a hole in 250mm concrete :D

https://digital.ucd.ie/view/ucdlib:47011 https://digital.ucd.ie/index.php?q=crumlin+area+6 https://www.irishtimes.com/culture/heritage/remembering-herb...

Just to add: there were many identically dimensioned houses built in parallel, of brown or yellow brick. These were at junctions, roundabouts and along major roads, but the majority are concrete. I've seen it humorously referred to as "Simms City".

Timber-framed or post-and-beam are a great alternative to concrete skeleton, but sadly very few residential areas are zoned for it. Much cheaper and faster than platform framing, works for both commercial and residential.

Post and beam was significantly more expensive than stick frame, as of the last time I looked into building a house.

How? You use fewer materials, simpler installation, it goes up faster. Specialized contractors?

Likely because you need to hire a structural engineer to sign off on the project.

Building codes allow us to do this sort of thing without direct engineering input and most municipalities have not adopted a code that define safe practices for this sort of construction. Additionally, materials selection and availability is geared towards stick frame construction and you may not have everything you need from big box hardware stores or local supply houses.

You need a special contractor, and structural insulated panels for walls/floors. That said, the total man-hours of labor are probably less, and according to timber-framing contractors I've spoken with over the past three years, the price gap is now less than 10% more than traditional stick-built.

Stick frames can go up remarkably quick. The install also doesn't need any specialized tools that contractors don't already have, so speed and labor isn't much of an issue.

Getting long beams from a log tends, I think, to be harder than getting small dimensional lumber. The timber also tends to need to be higher quality, especially if you opt for a design where they are exposed (such as vaulted ceilings).

Mostly, it probably comes down to where you live and how available the materials are; if good timber is easy to get, there's probably more contractors available who are accustomed to working with it.

> If you have ever wondered why you see basements in colder climates (and conversely more slab-on-grade in warmer ones) is because the bottom of your construction need to be situated under the frost line to prevent shifting caused by the ground freezing.

The other reason I've heard is that many warmer climates in the US are also very wet. Along the Gulf Coast, you basically can't have a basement unless you want there to be an unanticipated swimming pool in it because the water table is only a few feet below the surface.

There are some very cold areas where nobody builds a basement for this reason, they dig in footings or drive pilings to get below the frost line. where water table is not an issue though the cost to dig out a full basement isn't much more than just the footing and you get some semi-usable space.

To slightly contradict my original statement, cabins (or recreational use homes) are an example of buildings in colder climates where a foundation may be pier and beam rather than basement. Part of this has to do with the fact that mountains are literally raised areas of bedrock with some tiny amount of topsoil on them so it's likely you'll dig and hit solid goddamn limestone.

I have heard that too, I am not sure how true it is. You pretty much won't find a basement in Texas anywhere, even though the water table is hundreds to a thousand feet deep most places. In Harris county (where Houston is) 1 out of 11 measurement wells is cutting it close (17 feet) the rest are over 90 feet deep.

https://waterdatafortexas.org/groundwater

Texas has expansive clay in much of the state. This type of clay makes basements impractical.

I figure that is the answer in general. Most places have ground conditions of some variety that add cost and have special engineering considerations specific to the region. A second floor above ground is cheaper, easier, and the same everywhere.

This is very true and something I didn’t mention (I don’t live in an area where this is a problem). If it’s just a little bit of water and a sump pump can be used or you are able to install a water-resistant concrete sealant, a basement is possible, just cost prohibitive for your average house.

Many countries of the former Soviet Bloc built entire neighbourhoods from prefab concrete slabs -- I'm sure you're familiar with the awfully drab aesthetic these brought.

The construction of these was relatively straightforward though, and (especially important in apartment buildings), the solid concrete walls have great soundproofing qualities.

With a bit more expense, these buildings could've been made to look more attractive, and have more variety in terms of floor plans. I've been following some of the building automation trends, and the pre-fab components approach seems to best balance the many concerns.

As you mentioned, I'd attribute this to the cost and not the material. In Latin America having "exposed concrete" walls or ceilings is it's a whole trend right now. The look of course involves nicer, well-worked cement, and tends to be paired with either dark woods and metals painted matte black, or light woods and linen whites.

Some examples:

[1]: https://www.planosdearquitectura.com/diseno-departamento-dup...

[2]: https://www.lahaus.mx/ed/tulum/nativa-tulum

[3]: https://www.legacysir.com/sales/detail/10-l-647-c9gshd/av-de...

[4]: https://www.icasas.mx/venta/departamentos/ph-estilo-industri...

[5]: https://www.portalinmobiliario.com/MLC-1421396709-moderno-de...

This rhymes with the tend in the US pre 2020 of fancy live/work, urban lofts that look like industrial spaces with exposed brick, masonry, metals, etc.

Cottagecore was a sort of backlash to that movement - especially during a time where we needed to stay physically distance from one another and had to make solitude look more attractive a la provincial life.

Edison's Patents Regarding Concrete Houses:

Process of constructing concrete buildings: https://patents.google.com/patent/US1219272A/en

Apparatus for the production of concrete structures: https://patents.google.com/patent/US1326854A/en

The first was cited by John Zachary Delorean in a patent titled "Building construction." [0] DeLorean managed the development of a number of vehicles throughout his career, including the Pontiac GTO muscle car, the Pontiac Firebird, Pontiac Grand Prix, Chevrolet Cosworth Vega, and the DMC DeLorean sports car, which was featured in the 1985 film Back to the Future. He was the youngest division chief in General Motors history, then left to start the DeLorean Motor Company (DMC) in 1973. [1]

0. https://patents.google.com/patent/US3778953A/en

1. https://en.wikipedia.org/wiki/John_DeLorean

Even outside the US, concrete houses are not very common outside specific architectural styles like brutalism. What is very common are reinforced-concrete structural elements, but the walls themselves are made of bricks and mortar, or even concrete blocks, but rarely cast concrete.

A non-profit just created a 3D printed concrete home in Detroit. It cost over $230,000 although they expect in volume the cost would drop.

https://www.detroitnews.com/story/business/2022/10/18/detroi...

You can buy a pretty nice house in a nice neighborhood in Detroit for under $150,000 and a decent one for $75,000. Both far larger than 1,000 square feet and featuring two car garages as well. So the only market I can see for these homes is government subsidized projects.

First cars vs horses would be an apt comparison here. Automation had been slowly displacing human labor... the question is when, not if.

I can buy a shed from Home Depot for <$1,000 which is $229k less than that concrete home in Detroit if all we want to compare is price. So the question is how good are those $150k and $50k houses? If they're anything like the rest of American housing stock, they have utter shit for sound insulation, andmoft aren't much better for heat/cold insulation. Not that concrete is any good for thermal insulation, but sound insulation is a very underrate but very critical aspect for anything resembling dense housing.

> You can buy a pretty nice house in a nice neighborhood in Detroit for under $150,000 and a decent one for $75,000.

That’s probably under cost of construction, though, right? Maybe this is just way cheaper in the US than here, somehow, but current all-in cost of construction in Ireland for a one-off house is on the order of 2500eur/sqm, so about 250k eur for a house this size.

Anyone reminded of Tesla's gigacasting? Pop out an entire car frame as a single part from molten steel, versus 400 separate parts:https://www.reuters.com/technology/gigacasting-20-tesla-rein.... Wonder if we could do this with houses now.

Perhaps cast from AL a set of standard panels which can then be bolted together and have shotcrete and insulation be sprayed against them. The AL would remain on the exterior. All kinds of cool designs possible. They could do all that in a factory and ship out modules.

If it can't fit down a highway or requires a crane to install you're not going to save much money when compared to labor is my understanding.

Menlo park was also made of Edison concrete. https://www.menloparkmuseum.org it looks like it's in great condition, so is a certain road on the east coast. Forgot the Edison concrete contracts, but the old stadium was also made of Edison concrete. I always wondered about it's makeup, it's an excellent concrete.

Concrete is probably underutilized as a building material for homes in the US. Though there are high carbon costs for cement production, there are a lot of benefits to concrete: very strong against wind, very fire resistant, impervious to most pests, sound proofing, air-tight, good insulator when sandwiched with foam. https://www.iconbuild.com/ isn't yet 3D printing concrete homes at scale, but they have a small neighborhood of some really good looking homes going up in Texas.

> there are a lot of benefits to

One disadvantage: much harder to do changes / remodelling down the road.

Cinder block may be better for later flexibility than poured concrete:

* https://en.wikipedia.org/wiki/Concrete_block

Most of the time, rebar and concrete is placed and poured in the vertical column created by laying the block effectively turning into a vertical slab. It’s so much easier to build a wood-frame dummy wall on the inside to house utilities.

Unfortunately, concrete production is a pollution problem.

Cement industry accounts for about 8% of CO2 emissions

https://www.cbsnews.com/news/cement-industry-co2-emissions-c...

This number keeps growing because all of the other emissions are finally going down. I memorized it as five percent a decade ago.

It's a point source of carbon, which is the best case for capture. Some of the carbon could be made into plastic (particularly polyoxymethylene would be easy) although you might find that demand is saturated well before you have used up all of the capture.

Bigger problem is that due to the extreme temperatures required (the essential crystal structure, called alite, can only form above 1250 C) the facilities are large, expensive to construct and difficult to modify. Because the reaction produces a dust plume, they are often sited in less regulated jurisdictions, which compounds the problem. But capturing the carbon and capturing the dust likely require some common components.

This is arguably an opportunity for Latin America, which has historically had low local cement production due to tighter environmental regulations vs Asia. Its road and rail infrastructure lags as a result. (The durability of PC is also highly desirable in tropical environments!) But a proper implementation of clean cement is not yet well understood, and economic incentives for cleaner imports are merely theoretical at this point.

Cement is so c02 intensive largely because the chemical reaction which occurs release a large amount of c02. From what I remember the energy use for the furnace is 10% compared to 90% from the fundamental chemistry.

This is what I remember from working for a start up that was helping make low carbon cement, the numbers could be wrong, but it's more complicated than just the energy to reach the high temps.

We need to bioengineer vines or something, actually bacteria would be best, to grow insanely fast. Then grow them while the slab cures.

Then after grind them up as mulch abd fertilizer.

We can outfit the bacteria with a natural inhibitor. Maybe a lack of lysine.

Yeah. That'll work.

Some researchers are experimenting with additives of various sorts to use concrete for carbon sequestration: https://news.mit.edu/2023/new-additives-concrete-effective-c...

The obvious economic quirk about capturing carbon in concrete is that given time and pressure you can convince carbon to harden. Concrete that continues to pull in carbon in its process in theory has good chances to be stronger and hardier. If it continues past the initial set, you get "self-healing" concrete.

You joke about plants, but yes plants have been doing variations on that for epochs now, there is probably some more lessons to apply from them if we want to build a "diamond age" with all the excess carbon we've spewed as a culture.

Additives might be useful, but there is potential to weaken the concrete, and that'd make things worse, not better. EG, forcing rebuilds too often.

The reason I diverged from vines, is because multi-cellular is too slow. I think what we'd need to do, is create some sort of thin mat you lay over the concrete, just unroll it, and it has dormant bacteria along with whatever input(food) it requires to consume CO2.

So it then, much like yeast in bread, multiplies quickly, and you're left with a thicker mat to roll up and dispose of, grind up, say for fertilizer.

I envision the mat to be thin, akin to plastic rolls you get to keep insulation in place. They could be comprised of entirely organic materials, food for the bacteria. You know, such a thing should be possible, but would the bacteria multiple quickly enough? And likely water would be required as an additional.

High carbon cost of cement for sure (until we find viable new materials to bring that down which companies are actively investing in). That said a concrete home, if properly built, lowers the lifetime costs of CO2e as you have better heating and the product life is exceptionally longer!

Too many contractors can’t get concrete right. I see so many new builds with cracks and spall damage. So many basement or garage slabs with a few big cracks in them. Stick frame is more fool proof for sure

The problem is too many contractors are crooks.

Most of the world lives in concrete buildings.

There's a problem of where to put the infrastructure. If you lay pipes inside concrete, they're really hard to maintain. So, often plumbing, electrical, and HVAC just punch through the walls to outside equipment, plumbing, and conduit. Look at small low-cost housing in Asia. Mini-split air conditioners and pipes all over the exterior.

<So, often plumbing, electrical, and HVAC just punch through the walls to outside equipment, plumbing, and conduit.>

That's true for commercial bldgs, but almost all home dwellings in America with slab foundations have the plumbing and some hvac lines inside the slab. Repairing water and sewer lines in these homes is very expensive.

If I understand correctly from my neighbors’ experiences, they just cut up your walls and put new pipes in there and in the attic when the time comes that you inevitably develop a slab leak. it seems like this is probably a case where it has plenty of advantages for the first owner/1st 30 years (pipes neatly out of sight on the first floor) and when it eventually fails, it will be someone else’s problem besides the original builder or even original owner in most cases. Maybe this has changed in recent years though with the switch from copper to PEX, idk if they can just put that in the slab.

In New Zealand PVC pipes are used in concrete slabs for sewage, which in theory should last something like 75+ years. Water, I think, is still put in the dry wall cavity.

That's correct for water lines, and is expensive. But drain and sewer lines are in the slab. Just imagine the cost of removing your tile flooring, then cutting up the slab, removing the usually copper drain line (on older homes), laying new PVC, back filling with sand or gravel, THEN recovering the floors. Carpet would be a little cheaper.

Doesn't that just imply that a concrete home would have this problem everywhere, instead of just in the foundation?

You could do what they do in larger US buildings. Non load bearing walls are not made of concrete so vertical pipes go into those walls and are encased in drywall. Bathrooms and so on have their horizontal pipes below the ceiling of the space underneath, covered by drywall, so just need to punch a single hole in the concrete floor per pipe.

> If you lay pipes inside concrete, they're really hard to maintain.

I'd like to introduce you to a magical invention... it's called "ducts" :-)

You can have them behind walls, above ceilings, between rooms, between housing units etc. Of course, if the building was not build with maintenance in mind, or neglected to consider future potential needs (e.g. HVAC not catered to in buildings from the early 20th century) - then you have to run things on the outside; but even in those cases, new external ducts can often be constructed, using concrete or other materials (e.g. metal frames and whatever you like as cover, e.g. cement-board, sheet metal etc.)

Yes, you can, but people don't like it. There's classic Wiremold, but put that in a house and the value drops. There is an exposed plumbing as an aesthetic thing, but it's not popular.[1]

[1] https://www.graana.com/blog/concealed-vs-exposed-plumbing-di...

Didn’t know that was a thing. I love it.

The link gives me:

"The owner of this website (www.graana.com) has banned the country or region your IP address is in (IL) from accessing this website."

I guess maybe it's a protest against that genocidal war the government here is waging on Gaza.

Sure, if you were smart enough to have… all your ducts in a row. Ahem

In Latin America hollow brick is often used for walls. I'm not in the construction business, but I'm guessing it has to do with cost, insulation, and the ease of breaking in a crevice to lay conduit lines.

If you want to install a line and there isn't a pre-existing conduit in the wall, you do have to chisel one in. It's definitely more effort than with a "hollow" wooden wall, but it's not terribly bad.

> Look at small low-cost housing in Asia. Mini-split air conditioners and pipes all over the exterior.

I'd attribute this to the "low-cost", not necessarily the "brick/concrete". I'd imagine in the USA houses would be pre-fitted with more conduit, and homeowners could afford the installation of more as needed.

Wood is also very strong against wind if engineered correct. Both need something else to air seal as air will go through. Yes it is fire resistant, but unless your insulation and other building material is also fire resistant you gain nothing important: either way a fire will gut the house and need expensive work to repair. Wood is also a good insulator when paired with insulation.

Concrete is a useful material to build with. However it isn't the miracle that many advocates claim.

Here's a detailed walk through of the Lennar development from last month by a pretty detailed home builder/contractor:

Revisiting Lennar & ICON's 3D Printed Neighborhood 6 Months Later with Matt Risinger

https://www.youtube.com/watch?v=fPTps7e9SqY

Here's one of the homes at the level of a lay person's level of knowledge:

Inside a 3D Printed House That's Actually (kind of) Affordable

https://www.youtube.com/watch?v=qG7KMjV8zMk

That Matt Risinger video is exactly the one I watched that educated me that this process has gotten beyond the prototype stage. Great videos, but I usually watch on 2x speed because the information density is kind of low otherwise.

The purchasing power equivalent of $1,200 in 1990 is about $40,000 today.

I mean… 1900. Noticed it too late for an edit.

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