What do the British know about sustainable, energy efficient Modular Construction that the US is just now learning?

The European home construction marketplace has thoroughly embraced off-site construction.  Over 30% of all of the new housing in the UK is built using factory construction methodology.  Why then has the US been slower to adopt modern modular construction techniques such we employ here at Capsys?  Interestingly, the author of the following article suggests that the UK was forced to adopt sustainable construction earlier than the US due to its adoption of the Kyoto Protocol in the late 90’s that required substantial reductions of greenhouse gas emissions. 

While we talk a good Green game here in the US, the British have become leaders in Energy Efficient building and Modular Construction is their secret weapon.

http://www.jetsongreen.com/2011/10/modern-methods-offsite-construction-mccaughey.html