The goal is to encourage the uptake of energy-efficient technologies in buildings and increase the numbers and scope of refurbishment that would otherwise not take place. Therefore it is important that tax relief be targeted at new and innovative technologies with little market access and high upfront costs (Geller 2006, pp. Surveys of free-riders for various former US tax incentive programmes in the buildings sector have indicated possible rates between 53% and 94%. The number of free riders clearly depends on the design of each programme and in order to address the issue, the US federal government is now targeting incentives at only the most efficient measures and appliances with a market share below 5% (Neuhoff et a!.,