The quality of modern lumber is simply far inferior to the quality of lumber they were using to build homes in the early and mid-20th century. Wood quality began dropping on a serious scale in the 1980s due to old-growth timber being almost completely depleted. Most wood used today is grown very fast - not only can you visibly see the difference in quality, but the newer lumber is more prone to rotting due to a lack of heartwood. Slow-growth wood yields much more heartwood, which is the longest-lasting part of the tree, whereas sapwood (new-growth wood) will rot very quickly. Modern lumber is also a lot more prone to termite damage as it is softer and easier to consume whereas old lumber is extremely resinous and naturally termite resistant. A good rule - as long as the plumbing and electricity have been updated, a well-built home from the mid-20th century is a better investment.

Newer isn't always better.

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