Re: would you Americans build from metric plans?
I've got a March '06 Scientific American here ... ummm, March 1906.
It says:
The standards of length of the United States are two meter bars, which are kept in the custody of the National Bureau of Standards in Washington, and preserved most carefully in its strong vault. These standards are exact copies of the international prototype meter, and were constructed after years of investigation and labor by the International Bureau of Weights and Measures, being delivered to the united States government in 1899. Three years later the international meter as thus represented was adopted as the fundamental standard of length of the nation by executive order, and to these standard bars now all measures of length in the United States must now be ultimately referred ...
So you've all been building in metres, anyway. 
Andy
'There isn't a lovelier place in all the world,' thought Dorothea.