Construction Physics

Here’s the blog, by Brian Potter. If I can craft useful questions I’ll ask Brian for an interview. If you sample 3% of every good blog you find, the benefit to you is much larger than 3% multiplied by blogs you sampled! Highlights from Brian’s five earliest posts to convince you to sample more of it:

Look at an old set of construction documents, and you'll find construction details and structural systems nearly identical to the ones used today. Open up a design manual from the 1920s or the 1930s, and you'll find it depressingly applicable to today's buildings. Dimensional lumber, plywood, reinforced concrete, hot-rolled and cold-formed steel sections, metal roof deck, pre- and post-tensioning - almost every building framing system currently in use has been in use since the 1950s, and in many cases far earlier.

Materials remain similar as well. Modern construction steels are only slightly stronger than those of the early 1900s. Higher strength concretes are available, but any given project will likely use a 3000 psi mix no stronger or more durable than was used 100 years ago. Woods have actually gotten weaker over time in many cases, as lumber from old growth forests has been replaced with younger, farmed trees.

And:

Manufactured homes are one of the few building types that are decoupled from the land they sit on - the purchaser generally needs to buy the land separately (though around 30% of manufactured homes do get placed in manufactured home communities).

And:

Other than economizing on materials, manufactured home suppliers are able to achieve such low prices by relying on alternate sources of revenue (much like Costco). Skyline Champion sells transportation services through Starfleet Trucking. Both Clayton Homes and Cavco (combined around 60% of the manufactured home market) offer financing for the homes they sell. Cavco makes 20% of its profit from its financial services division, and Clayton, in addition to offering home financing, also offers insurance.

And:

Homes are built essentially as wide as transportation laws will allow - the homes have gotten wider as the transportation laws have changed to accommodate them (40 years ago few states allowed 14 foot wide homes to be transported, now that has become the standard home size). And despite their size, they can be installed with a small crew without using a crane.

And:

And where a site-built home tends to appreciate in value, a manufactured home will lose value if it’s not financed as real estate, which few are. They’re generally financed as personal property, and subject to higher interest rates than typical mortgages.

And:

95% of the energy required for manufacturing lumber products comes from the kiln drying process, which brings the moisture content of wood below 20%. But this process can be fueled by burning the wood detritus left over from sawing the logs down into planks. 65% of a sawmill’s energy comes from burning this waste wood - an energy source that has no transport, logistics, or refining costs (since it’s right where the wood has been sawn) and is carbon neutral (since it’s just releasing the carbon the wood fixed in the first place).