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Comment by varjag | Hacker News Reader

While am generally a 3d printing skeptic I feel it's not quite a fair take. The bulk of a house (and its major cost component) is the structure. So this could be useful even if it can't print you the bathroom and the fridge.

How well it going to work in practice is another matter (and here's where am skeptical).

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The bulk of a house (and its major cost component) is the structure

Using current pre-fab techniques a half dozen builders can raise the core structure of a single family house in a few days. A friend of mine is in the process of building a house and raising the core structure was the fastest and easiest part of the whole process. I don't see this being either cheaper or faster.

The bulk of the cost in many cases is things independent of the actual house, like purchasing the land, doing the ground work and the foundations and pulling in water and sewage.

Well lumbar is expensive too now.

True. The question is if that is just a temporary thing or the new normal. I suspect prices will be back to 'normal' in a year

There was a deep dive about this in Bloomberg Odd Lots podcast. Although some of the price increase was due to the industry predicting lower demand and getting rid of inventory. Another, more fundamental factor is the actual scarcity of lumber due to lower harvesting quotas set by Canadian govt. These quotas are unlikely to go up any time soon.

They aren’t going to maintain a 3x increase in price though. If they do we’re going to see a lot of new sawmills starting up.

That's misleading when comparing this.

There's a typical expectation of manufactured parts or prepared wood for a wood frame building. (It's not instantaneous to season wood for house building, and it's longer than this structure drying)

I have looked into building a house a few month ago, the wait time for the structural lumber components to be manufactured to the spec - 3 months. "Raising the barn" part is hardly the long part.

Houses can also be “stick built” from lumber on site. The trusses will usually be manufactured so that they are all identical but they are generally quick barring any backlog of work.

Absolutely not true. This is often referred to as the 'envelope' in construction and its not the majority of the cost of overall construction (or wasnt before the current outrageous lumber prices)

> The bulk of a house (and its major cost component) is the structure

That's blatantly false, the structure is the easy part.

The structure also has to accommodate those features. They’re not wholly independent.

With pex plumbing and high velocity HVAC, you only need to run small, flexible tubes through the framing. It should be relatively easy to print small, flexible holes for tubing. Agree that traditional ductwork and copper pipping would be hard to accommodate.

Drainage is the hard part. The pipes are larger and require you to cooperate with gravity.

Sewage is absolutely NOT a problem for a single story houses. No large sewage pipes are installed in the walls of all single story houses.

Sometimes they are. My house is single story and has sewage pipes in the walls. Regardless of whether that is a requirement, the pipes have to go through some part of the structure to get to the outside, regardless of whether that's a wall, floor, foundation, etc.

It’s possible but only done for convenience where it makes sense to, not a requirement for new construction since you just put the pipes in before the pad gets poured.

Yes but GP said large pipes, e.g. for a toilet or the main pipe that connects to the municipal sewer. In a single-story house these would be under the floor. Pipes in the walls of a single-story house would be sink drains or vent pipes, and are narrower.

Your toilet pipes are inside a wall? That’s pretty strange, toilet drain pipe is usually 3” dia. Are there 90 degree bends? I don’t understand how or why you’d put a toilet drain pipe in a wall when the drain pipe is in the middle of a bathroom floor, not in a wall.

Are you sure you aren’t thinking of sink drains?

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