I'm an electrician, I have worked on all kinds of housing and buildings, old, new, prefab etc.

What I think he is saying is that it is similar to prefab buildings. With such designs, wires, plumbing, and general utilities are all pre installed and simply need to be hooked up to mains once the structure has been put together. In Altman's example, I believe he is looking at 3D printing specifically. Similar ideas have been proposed for Luna and Mars bases.

Essentially utilising the raw materials within the proposed structures environment. Piping would actually be pretty simple. It can be ceramic, for example. However, when it comes to electricity, you need conductive material that is not found just anywhere.