This regulatory impact statement was prepared by George Wilkenfeld and Associates and released in November 1999. This document is a supplement to the original RIS. It does not reconsider the issues of mandatory vs voluntary labelling, or mandatory vs voluntary MEPS. The original RIS found that part of the case for mandatory MEPS was that, unlike voluntary labelling, it provides a framework in which the effectiveness of energy labelling can be increased. This document supplements the original RIS, by:Describing the proposed process of transition to revised energy labels;Estimating the costs involved in the process;Establishing whether the costs are consistent with the assumptions made in the original RIS;Clarifying the benefit/cost ratios for measures to enhance labelling effectiveness, as estimated in the original modelling.