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3D printing doesn't relieve any important construction constraints and probably raises costs because unfamiliarity increases risks and increased risk increases

3D printing doesn't relieve any important construction constraints and probably raises costs because unfamiliarity increases risks and increased risk increases price. Superstructure is about the easiest and fastest part of residential construction. Sitework, finishes, and MEP systems are harder, tend to take longer, and cost more. Anyway, market rate housing sells at market rates no matter how it is built.

liontwist 2y ago
> market rate housing sells at market rates no matter how it is built. This is true. Do you see any opportunity for efficiencies in rebuilds?
- brudgers 2y ago
  What do you mean by “efficiencies?”
  - liontwist 2y ago
    Like you mentioned the market for housing is more about where people want to live, and the actual building on it is less important (up to first order quality and space), so that optimizing construction costs doesn’t really save money on housing. But suppose we have a country of aging housing. Could prefabrication techniques result in lower costs when replacing existing buildings without a land transfer?
    - brudgers 2y ago
      1. In successful businesses, lower costs usually correlate to greater profits not lower prices. This is particularly the case with the narrow section of the real-estate market that is single family housing (single family housing is about the lowest and worst use of real-estate (i.e. the opposite of highest and best use)). 2. Single family home construction in the US is highly prefabricated. You can go into any Home Depot and get lumber, fasteners, fixtures, appliances, and anything else you need to build a house. All of it movable and installable without much mechanization beyond a truck (and Home Depot will rent you one of those). 3. Tearing down existing houses for replacement only makes economic sense in two cases. The first is when the value of the land justifies more expensive construction (e.g. MacMansions). The second is when redevelopment is not for the market (e.g. Habitat for Humanity). 4. It is a mistake to look at construction as inefficient. Construction is just one component of real-estate markets. 5. We have very efficient prefabricated housing. It tends to look like mobile homes. 6. Wealth preservation is the primary function of the real-estate industry. Buying and selling for profit is the low end. The real money in real-estate resides in income producing property not single family houses.
      - eightysixfour 2y ago
        > 3. Tearing down existing houses for replacement only makes economic sense in two cases. The first is when the value of the land justifies more expensive construction (e.g. MacMansions). The second is when redevelopment is not for the market (e.g. Habitat for Humanity). Interesting you chose “MacMansions” as the example instead of increased density. In my (very) urban area they tear down single family homes and replace them with 6-9 town homes.
        brudgers 2y ago
        I chose MacMansions because it was clear and ordinary and uncomplicated. Building a six pack is driven by the same basic economic condition, the existing building is economically obsolescent.
- aleph_minus_one 2y ago
  > This is true. Do you see any opportunity for efficiencies in rebuilds? When this technology has become much more established, the "risk premium" can be decreased by a lot. Then one can start to find methods to make the process more economic. And I see quite some potential there, because 3D printing can potentially be done in a much more "automatic" way than other existing house building processes.
pxmpxm 2y ago
>Superstructure is about the easiest and fastest part of residential construction. I'm perpetually confused on that front - interior, especially drywall, is stupid labor and time intensive (have to wait for taped joints to dry). There should be huge econmomies of scale for prefab walls with electric and ducting built in, yet all we see is this sort of 3d printing stuff.
- brudgers 2y ago
  How do you finish the joints between sections of prefabricated walls? Where do you store hundreds of running feet of prefabricated wall during construction delays? How do you move sections of prefabricated wall into and within a dryed-in building? How do you trim a section to fit and extend another when construction is not ideal? Who is responsible when something is not right? And of course there’s getting UL listings for any proprietary electrical connections and issues of inspection for code compliance. Prefabricated walls are common and are suitable for cubical farms. They tend to cost more psf than regular construction but can be depreciated as furniture and reconfigured more easily than site built walls and fixtures.
  - wombatpm 2y ago
    Standardized wall sections, JIT inventory management, dedicated install teams?
    - dhosek 2y ago
      My parents’ home, built in the 1950s was built from pre-fabricated components. From what my dad says (his mother was the original owner of the home), the fit of walls was very poor and they had to do a lot of patching to fill in gaps between the walls and the ceilings. There have been numerous attempts at prefabricated building but all have failed to gain any traction.
      - teruakohatu 2y ago
        A lot of homes in New Zealand were sent over 150 years ago from Australia and Europe as prefabricated kits. Apart from the abysmal lack of insulation, they are still going strong. Right now most new houses have the wood framing CNC manufactured based on plans, shipped to the building site and assembled, then modified as needed by the builder. Our roofs are almost exclusively steel, which are also CNC cut and shipped to the site and installed by roofers.
cbames89 2y ago
It's ~21% the cost of a home, it's actually the single most costly and labor intense category. That being said it does only take 14-21 days to frame a home.
- brudgers 2y ago
  At scale it takes significantly less time because the designs are familiar and there are not mobilizations and demobilizations. The next framing job is on the next lot.
  - janalsncm 2y ago
    So if a technology could cut that cost in half it would be desirable even if it took twice as long because in real terms your final cost drops 10% and only takes 2 more weeks.
    - brudgers 2y ago
      It would depend on what else was in the spreadsheet.
jqpabc123 2y ago
Anyway, market rate housing sells at market rates no matter how it is built. This is a demonstration project. If there were any economic advantage, I would expect them to be eager to demonstrate it. But such does not appear to be the case. $450-600K for a simple, single story ranch 30 miles outside of Austin is not exactly awe inspiring.
Dig1t 2y ago
Many of these printed homes just leave the concrete exposed inside the home. They can just be painted directly, and they are also well insulated already so you don’t need to fill the wall with insulation. So not only are you framing differently but you can skip the drywall and insulation steps of construction as well. This is the type of finish work you are talking about I think.
- brudgers 2y ago
  You still have to mobilize a drywall crew for ceilings. And your painter needs to use another primer and paint system for the concrete. Hanging interior doors and trimming them out is no longer a job for nails. Same for crown and base moldings and kitchen cabinets. And you still have to insulate. Four feet of concrete wall thickness is needed for a nominal R10.

liontwist 2y ago

> market rate housing sells at market rates no matter how it is built. This is true. Do you see any opportunity for efficiencies in rebuilds?

brudgers 2y ago
What do you mean by “efficiencies?”
- liontwist 2y ago
  Like you mentioned the market for housing is more about where people want to live, and the actual building on it is less important (up to first order quality and space), so that optimizing construction costs doesn’t really save money on housing. But suppose we have a country of aging housing. Could prefabrication techniques result in lower costs when replacing existing buildings without a land transfer?
  - brudgers 2y ago
    1. In successful businesses, lower costs usually correlate to greater profits not lower prices. This is particularly the case with the narrow section of the real-estate market that is single family housing (single family housing is about the lowest and worst use of real-estate (i.e. the opposite of highest and best use)). 2. Single family home construction in the US is highly prefabricated. You can go into any Home Depot and get lumber, fasteners, fixtures, appliances, and anything else you need to build a house. All of it movable and installable without much mechanization beyond a truck (and Home Depot will rent you one of those). 3. Tearing down existing houses for replacement only makes economic sense in two cases. The first is when the value of the land justifies more expensive construction (e.g. MacMansions). The second is when redevelopment is not for the market (e.g. Habitat for Humanity). 4. It is a mistake to look at construction as inefficient. Construction is just one component of real-estate markets. 5. We have very efficient prefabricated housing. It tends to look like mobile homes. 6. Wealth preservation is the primary function of the real-estate industry. Buying and selling for profit is the low end. The real money in real-estate resides in income producing property not single family houses.
    - eightysixfour 2y ago
      > 3. Tearing down existing houses for replacement only makes economic sense in two cases. The first is when the value of the land justifies more expensive construction (e.g. MacMansions). The second is when redevelopment is not for the market (e.g. Habitat for Humanity). Interesting you chose “MacMansions” as the example instead of increased density. In my (very) urban area they tear down single family homes and replace them with 6-9 town homes.
      - brudgers 2y ago
        I chose MacMansions because it was clear and ordinary and uncomplicated. Building a six pack is driven by the same basic economic condition, the existing building is economically obsolescent.
aleph_minus_one 2y ago
> This is true. Do you see any opportunity for efficiencies in rebuilds? When this technology has become much more established, the "risk premium" can be decreased by a lot. Then one can start to find methods to make the process more economic. And I see quite some potential there, because 3D printing can potentially be done in a much more "automatic" way than other existing house building processes.

pxmpxm 2y ago

>Superstructure is about the easiest and fastest part of residential construction. I'm perpetually confused on that front - interior, especially drywall, is stupid labor and time intensive (have to wait for taped joints to dry). There should be huge econmomies of scale for prefab walls with electric and ducting built in, yet all we see is this sort of 3d printing stuff.

brudgers 2y ago
How do you finish the joints between sections of prefabricated walls? Where do you store hundreds of running feet of prefabricated wall during construction delays? How do you move sections of prefabricated wall into and within a dryed-in building? How do you trim a section to fit and extend another when construction is not ideal? Who is responsible when something is not right? And of course there’s getting UL listings for any proprietary electrical connections and issues of inspection for code compliance. Prefabricated walls are common and are suitable for cubical farms. They tend to cost more psf than regular construction but can be depreciated as furniture and reconfigured more easily than site built walls and fixtures.
- wombatpm 2y ago
  Standardized wall sections, JIT inventory management, dedicated install teams?
  - dhosek 2y ago
    My parents’ home, built in the 1950s was built from pre-fabricated components. From what my dad says (his mother was the original owner of the home), the fit of walls was very poor and they had to do a lot of patching to fill in gaps between the walls and the ceilings. There have been numerous attempts at prefabricated building but all have failed to gain any traction.
    - teruakohatu 2y ago
      A lot of homes in New Zealand were sent over 150 years ago from Australia and Europe as prefabricated kits. Apart from the abysmal lack of insulation, they are still going strong. Right now most new houses have the wood framing CNC manufactured based on plans, shipped to the building site and assembled, then modified as needed by the builder. Our roofs are almost exclusively steel, which are also CNC cut and shipped to the site and installed by roofers.

cbames89 2y ago

It's ~21% the cost of a home, it's actually the single most costly and labor intense category. That being said it does only take 14-21 days to frame a home.

brudgers 2y ago
At scale it takes significantly less time because the designs are familiar and there are not mobilizations and demobilizations. The next framing job is on the next lot.
- janalsncm 2y ago
  So if a technology could cut that cost in half it would be desirable even if it took twice as long because in real terms your final cost drops 10% and only takes 2 more weeks.
  - brudgers 2y ago
    It would depend on what else was in the spreadsheet.

jqpabc123 2y ago

Anyway, market rate housing sells at market rates no matter how it is built. This is a demonstration project. If there were any economic advantage, I would expect them to be eager to demonstrate it. But such does not appear to be the case. $450-600K for a simple, single story ranch 30 miles outside of Austin is not exactly awe inspiring.

Dig1t 2y ago

Many of these printed homes just leave the concrete exposed inside the home. They can just be painted directly, and they are also well insulated already so you don’t need to fill the wall with insulation. So not only are you framing differently but you can skip the drywall and insulation steps of construction as well. This is the type of finish work you are talking about I think.

brudgers 2y ago
You still have to mobilize a drywall crew for ceilings. And your painter needs to use another primer and paint system for the concrete. Hanging interior doors and trimming them out is no longer a job for nails. Same for crown and base moldings and kitchen cabinets. And you still have to insulate. Four feet of concrete wall thickness is needed for a nominal R10.