The relevance is that it costs a certain amount to build a house in a certain area. It's a combination of labor costs, materials, and resources required to construct a house. If you weren't a builder (the insurance thing), it would cost you $349,000 to build a average detached 2,000 sq/ft house. This doesn't include land costs and presumes you own the lot. Sure, builders don't pay that because they gain efficiencies in mass production, scheduling, and bulk buying of materials, so they have a better return.
Most builders make approximately 10% return per house. If the house sells for $350,000, they make $35,000 profit after the land is paid for, all the taxes, all the levies, all the roads, all the sewers and the cost of the house built on it including labor and materials. This is for your cookie cutter mass subdivision builder (not the luxury or custom home builder who have a much higher return)
In the states there is an index for measuring the costs related to building homes. While some things have actually decreased in price, most are up and up large year over year.
My very point is that 10 years ago a builder could easily make a profit on a 2,000 sq/ft house for $299k in Milton, now it wouldn't even cover most of their costs -- so yes, prices have to rise after 10 years. They can't ever go back down to those prices unless we have a major supply issue like in the states where houses are selling BELOW actual value (not just inflated value, they are selling for less than it costs to build).
And yes, they are still building in the states -- but it's location, location, location. Nobody is building 2,000 unit subdivisions in Detroit.
http://romaclumber.com/news/whole-house ... pril-2011/
^^ This is very dependant on physical location but it does show you, all the materials to buy a house are also commodities and as such go up and down like anything else.
Japan, China, India = more demand for commodities.