; and (v) other technologies, practices, and building systems regarding building plug load and other energy uses. (B) Requirement In developing and adjusting the amendments, the Secretary shall use climate zone weighted averages for equipment efficiency for heating, cooling, ventilation systems and water heating systems, using equipment that is actually installed. (5) Economic considerations In establishing and revising amendments under paragraph (1), the Secretary shall consider the economic feasibility of achieving the proposed amendments established under this section and the potential costs and savings for consumers and building owners, by conducting a return on investment analysis, using a simple payback methodology over a 3-, 5-, and 7- year period. The Secretary shall not propose, or provide technical or financial assistance for, any provision in the code or amendment that has a simple payback greater than 10 years. (d) Analysis methodology The Secretary shall make publicly available the entire calculation methodology (including input assumptions and data) used by the Secretary to estimate the energy savings of code or standard proposals and revisions. (e) Methodology development The Secretary shall establish a methodology for evaluating cost-effectiveness of energy code changes in multifamily buildings that incorporates economic parameters representative of typical multifamily buildings. (f) Determination (1) Analysis If the provisions of the IECC or ASHRAE Standard 90.1 regarding building energy use are revised, not later than 90 days after the date of the publication of the revised code, the Secretary shall conduct a return on investment analysis of the entire code, by climate zone, using a simple payback methodology over a 3-, 5-, and 7-year period. (2) Determination If the provisions of the IECC or ASHRAE Standard 90.1 regarding building energy use are revised, the Secretary shall make a determination not later than 15 months after the date of the publication of the revised code, on whether or not the