Why hasn't prefab construction taken over? • Hacker News Board

Re: Why hasn't prefab construction taken over?

#111

Post by andrewflnr » Mon, Oct 12, 2020, 10:07 PM UTC

seibelj wrote: post #103

tw04 wrote: post #91

Earlier quoted context omitted.

> One big area where modular prefab can potentially make a difference is by reducing the need for skilled tradesmen, particularly electricians, plumbers and HVAC techs. To what end? As a country we're already struggling to create enough middle-class jobs and you're suggesting we try to gut another whole sector. So that owners/executives of prefab factories can pocket the money? If you think it's going to reduce cost…

This is the fallacy - The Fallacy - that is always made by those who don’t understand economics. Why did we build the car when it put all of the horse tradesmen out of business? Why do we use elevator buttons and put the doormen out of a job? Why did we create the Internet when perfectly good newspaper printers could pass information to us? You are making an age-old argument that we need to reduce productivity in ord…

This is potentially very much like saying, "we burned this little bit of fuel, and all that happened was the fire got brighter because it spread to more fuel! It can never go out!".

There's no reason to expect the job-generation cycle to last forever. In fact there's every reason to believe it can't. The question is whether it ends on a scale more like decades or centuries. To blindly assume that things will continue as they have is foolish. (To be clear, I think the solution looks more like UBI than Luddism.)

Re: Why hasn't prefab construction taken over?

#112

Post by ThatGeoGuy » Mon, Oct 12, 2020, 10:07 PM UTC

seibelj wrote: post #103

tw04 wrote: post #91

Earlier quoted context omitted.

> One big area where modular prefab can potentially make a difference is by reducing the need for skilled tradesmen, particularly electricians, plumbers and HVAC techs. To what end? As a country we're already struggling to create enough middle-class jobs and you're suggesting we try to gut another whole sector. So that owners/executives of prefab factories can pocket the money? If you think it's going to reduce cost…

This is the fallacy - The Fallacy - that is always made by those who don’t understand economics. Why did we build the car when it put all of the horse tradesmen out of business? Why do we use elevator buttons and put the doormen out of a job? Why did we create the Internet when perfectly good newspaper printers could pass information to us? You are making an age-old argument that we need to reduce productivity in ord…

I think your example isn't completely off the mark, but I do think the article itself actually answers this: there is a shortage in trade labour in the non-commercial construction sector in (North) America.

We are also at a cross-roads with regards to having a housing crisis. There are many places now (Bay Area, Boulder) where housing is skyrocketing not because the value is naturally increasing, but is instead being artificially inflated due to a shortage in homes. One "radical" solution to this: build more homes.

However, given the amount of labour and time needed to do so, we may not be able to avoid the housing crisis. One way the market is responding is moving to pre-fab construction, and trying to reduce time / costs that way. The article does seem to claim that the projects cost about the same, even if pre-fab is faster in terms of time. This _does_ identify a problem with pre-fab, namely, how come they can't fulfill this promise of being cheaper & faster. Seems strange that you save time but still cost the same when what you're proposing is taking away a significant chunk of higher-skilled labour from the equation.

Some of this is regulatory capture (wasted time / money trying to convince cities of the process), some of this is nascent technology sucking (see top parent comment, sometimes pre-fab doesn't get it right), and some of this seems to just be a lack of experience on behalf of the companies trying to "disrupt" construction.

Re: Why hasn't prefab construction taken over?

#113

Post by Ericson2314 » Mon, Oct 12, 2020, 10:09 PM UTC

Honestly I wish construction was less efficient, if only to guide us back to proper land use and dense developments.

Factory-churned suburbia is the last thing we need.

Re: Why hasn't prefab construction taken over?

#114

Post by michaelt » Mon, Oct 12, 2020, 10:09 PM UTC

hun-nemethpeter wrote: post #6

I prefer the Fastbrick Robotics ( https://www.fbr.com.au/ ) company's approach where they just creating building robots. Here is a short video on the robot in action: https://www.youtube.com/watch?v=HYsWbDA0xlc

It's neat, but where's the mortar between the bricks?

Re: Why hasn't prefab construction taken over?

#115

Post by yeetman21 » Mon, Oct 12, 2020, 10:12 PM UTC

jeffbee wrote: post #4

Prefab is the wrong optimization. It targets a minor improvement in a small part of the overall budget. Most of the time and money of construction in America is tied up in land prices, permitting, and regulation. Prefab solves zero of these issues. There is a building going up in Oakland right now where Factory_OS put out a press release that they had built it in ten days. But they spent 7 years getting approvals, 18…

Engineers can only fix so much, they can not really do permitting and regulation

Re: Why hasn't prefab construction taken over?

#116

Post by clairity » Mon, Oct 12, 2020, 10:15 PM UTC

the title is grossly inaccurate. this is an advertorial for the bone structure company's pre-cut metal framing system, not about why prefab hasn't taken over. it's central reasoning that prefab is advantageous because there's not enough construction labor is also misleading. in most places, construction labor much prefers bigger jobs and repeat clients, rather than the harder to deal with idiosyncratic, one-off homebuilder, leaving them with a perception of shortage (even the beginning anecdote mentions getting multiple bids on a project, which wouldn't happen amidst a shortage).

bone structure pre-cuts the steel framing for each project because it's not nearly as easy to deal with on-site as wood framing. it's also not cheaper, because wood framing is relatively available everywhere, flexible, reconfigurable on the fly, and easy to manipulate, unlike steel framing.

and as others have noted, framing is a small fraction of home construction, and these walls must be put together on site, so it's an overreach to even consider this prefab. it's just pre-cut.

that said, it'd be great to see more prefab systems, even just embellished boxes, to accelerate housing construction in tight markets, and ones like LA where homelessness is an already widespread and growing problem.

Re: Why hasn't prefab construction taken over?

#117

Post by Mvandenbergh » Mon, Oct 12, 2020, 10:16 PM UTC

So the question: Why hasn't prefab construction taken over?

Answer: It has, just not all the way.

Modern American construction makes extensive use of prefabricated roof trusses, for large developments it is common to see parts of the framing prefabbed. The drywall interior fixing systems are designed to substantially reduce the amount of on-site work required. Modern plumbing fixtures can often be snapped together or joined with glues/expoxies rather than needing to be soldered. Domestic electrical can come as pre-wired conduit and you better believe that large developments are selecting those sizes carefully to reduce on-site work. Windows and doors arrive as single units which just need to be fitted, again a lot of attention is paid to ease of fitting since they are selling to series building professionals for whom labour time is money. Kitchen cabinetry is supplied fully prefabbed.

Modern flooring is also based on easy-to-assemble systems. Compare the effort required to put in laminate vs old-school parquet, hardwood boards, or marble.

Of course if you just put a whole ground floor together in a few modules in a factory, you will save even more labour time. The question is whether the greater transport costs and reduction in flexibility* will make it worth it in the end.

(*) If your factory isn't mass producing the same product over and over, you're going to lose a lot of the productivity gains from factory production.

Re: Why hasn't prefab construction taken over?

#118

Post by ashtonkem » Mon, Oct 12, 2020, 10:17 PM UTC

stephencanon wrote: post #69

LatteLazy wrote: post #58

Earlier quoted context omitted.

Says the man who can afford to spend 3 years in court losing 15k :)

Anyone who takes on building a custom house can easily afford to spend 3 years in court losing 15k.

Usually they could before they built the house, but the phrase “house poor” exists in common parlance for a reason.

Re: Why hasn't prefab construction taken over?

#119

Post by v77 » Mon, Oct 12, 2020, 10:18 PM UTC

xster wrote: post #59

Depends where you are. The company that built pre-fab parts for the 10-day 1,000 bed hospital in China is building a Huoshenshan equivalent hospital in Korea too. 11% of global CO2 emissions are from construction. Using pre-fab steel modules are not only more recyclable but the building process emits about 50% less CO2 as well. Building in earthquake resistance is much easier than steel-reinforced concrete. So it's n…

You should look up some of the new structural wood techniques being used.

Re: Why hasn't prefab construction taken over?

#120

Post by yardie » Mon, Oct 12, 2020, 10:18 PM UTC

dejv wrote: post #54

falcolas wrote: post #16

This article seems to be missing some critical information - does this proposed system help with anything but the framing? Because framing a house, even a two story house, only takes an experienced crew a couple of days. And in the neighborhoods springing up around here, they are using pre-fab framed walls (still using wooden studs (which are cheap and plentiful), but they arrive on site as whole walls). Before frami…

We are buying house from company that is building them fully assembled: house is assembled indoor and include all electrical, plumbing, HVAC, insulation. Whole system is based on few types of modules that you can connect together and it scale from tiny house to standard house sizes and modules could be even stacked to get multiple floor levels.

This looks similar to the modular homes that were popular in the US in the 60s and 70s. Sadly, they went out of style because they earned the reputation of being cheap and flimsily constructed. This was because of all sorts of financial shenanigans.

At least in the US, banks are reluctant to back a mortgage to a home like this. Many of these modular homes are on leased land. Once the lease was up the house became worthless and had to be destroyed.