In France about 4.2 million households have benefitted from similar tax incentives between 2005 and 2008 which equals about 13% of the residential building stock, (see case studies in the annex for more information on tax incentives in France and Italy). Through tax credits for energy-efficient new homes in the US, the market share of eligible homes37 rose from 1% in 2006 to 10% in 2009 (ACEEE 2011a, pp. Another example can be found in US tax credits for non-business energy improvements put in place 2006 and extended several times until 2010. The most impressive effects of the US programme are found for Energy Star windows: the national market share rose from 49% in 2005 to 93% in 2010. Even though the incentive was cut back sharply in 2011 (from originally $1500 to $200), the market share stayed high at 89% in 2011 (ACEEE 2011a, pp. It is very difficult to assess how ambitious are performance requirements for the different schemes.