This week Eli and his team got a start on cutting wood for the house. I want to talk a bit about Eli's process, because it's very different than what I normally see done by builders. Rather than trucking raw materials to the site and cutting them to order on site, according to a blueprint provided by the architect, Eli (who is actually an architect among his other talents) has a really high-end CAD package he uses to prepare detailed drawings and cut lists.
This gives him a degree of precision in his plans that allows him to hand his cut lists off to his team, who pre-cut all the wood in the house and pre-assemble what they can in Eli's shop. This means that they can use tools that are set up on a nice flat concrete floor, and store the wood under the roof, and not haul stuff to the site that's going to have to be hauled to the dump afterwards.
I personally find this process both frightening and inspiring. Frightening because I would not have the confidence to go from a CAD drawing to cutting in a shop and shipping the results to the site. Inspiring, because this is exactly the right way to do a custom house: you design the whole thing in a piece of software that is intended to produce accurate cut lists. You have a crack team that can follow the cut lists and reliably produce a stack of pieces that really do fit together. You do as much work as you can in the shop. Then you load it all on a truck and bring it to the site.
This is where we are in the process now. Eli calls it "making sawdust." Eli's crew is going to be cutting and assembling all next week. Nothing's leaving the shop. I think they may still be doing a bit of cutting the following week as well.
Another key aspect of this process is that as the pieces are cut and assembled, Eli's crew marks them, so that when the time comes to put them together on site, all the measuring is already done. So at that point all the team has to do is put the pieces together according to the markings.
Why do I think this is so cool? Because it's efficient. A well-built house, which I think everybody should get when they buy a new house, requires a lot of labor. But a lot of that labor is dead time where you're hunting for things, or switching tools, or whatever. Builders put a lot of thought into saving time on the site, but by doing things in the shop, the time savings are substantially more.
Also, because Eli knows precisely how many pieces are going to go into the building, we started out with a clean bill of materials that we don't expect to have any substantial surprises on it, and Eli is also able to predict with some accuracy, based on his past experience with his team, just how much labor is going to be involved in assembling this.
Many builders brag about building to code minimum, as if that were an achievement, but really building codes are intended to enforce the absolute minimum level of quality, so that if your house was built to code, you at least don't have to worry that it's going to catch fire for no good reason or fall down in a minor windstorm. Many houses built to code minimum have flimsy walls, poor air quality, poor noise isolation, noisy floors, and crooked, flimsy fixtures. This saves money, and allows the builder to sell the house for a lower price, or take a higher profit. There's nothing wrong with either of these things, but if it were possible to make something better, wouldn't that be nice?
Andrea mentioned money in her previous post, and money is a real worry in a well-built house. The problem is that a home buyer has no real idea what actually went into the house that they are buying. They can't easily tell that they are getting a well-built house or one built to code minimum. Some things are obvious, but some things aren't until you've moved in. By using his CAD/CAM system, Eli is building our house for a very competitive per-square-foot price.
The result is that when this is done, we hope to have a well-built custom house without it being so expensive that if we should need to sell it, it would be impossible to recoup our costs. Anyway, that's the plan.
Ordinary houses breathe through leaky joints and poor seals, losing heat and wasting energy. But our house won't leak, so we'll use a heat recovery ventilator (HRV) to admit fresh air and expel stale air, transferring heat from one stream to the other.