Originally Posted by
Neuro
I recommended a friend of mine who was building a villa in Sweden some 15-20 years ago to pre-treat it with iron sulfate, and he did, because you never need to paint the house again, and it gets this silvery tone like really old untreated houses get over time, but within a year, and it cost like $10. So today I decided to read up on it re the science. Apparently untreated houses generally last better than painted houses, depending a little on the paint, and if you build the wall correctly with roof protection against moisture (like your roofs), the iron sulfate may add some extra protection against fungus, but not very much against UV-decay. The problem with most paints is that it keeps the moisture within the wood, and if you don't repaint it with proper intervals (which almost always happens in a life time of a house), you'll get a crack in the paint that lets in water, and the paint doesn't let it out and rot starts.
There are wood houses in Sweden that were built 300 years ago, with your type of construction, untreated, that are still standing somewhat intact today.
Good you didn't paint it!
Another option if you want to paint it later on, which would protect against UV decay (about 1/3-1/2 inch in a 100 years) would be to use this Swedish paint which essentially is a mix of iron oxide, rye flour and water. Called in Sweden "Falu Red", may be known other places as "Swedish Red". Which my 130 year old outhouse is painted in, and I repainted a couple of years ago, you have to keep repainting it every 10-15 years though, as it starts looking ugly.
Btw, will you be able to keep your fancy tax payer funded swimming pool?