; (E) performance-based standards; (F) evaluating economic considerations under subsection (b)(4); and (G) developing model building energy codes by Indian tribes in accordance with tribal law. (3) Amendment proposals The Secretary may submit timely model building energy code amendment proposals to the model building energy code-setting and standards development organizations, with supporting evidence, sufficient to enable the model building energy codes to meet the targets established under subsection (b)(2). (4) 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. (d) Determination (1) Revision of model building energy codes If the provisions of the IECC or ASHRAE Standard 90.1 regarding building energy use are proposed to be revised, the Secretary shall make a preliminary determination, by not later than 90 days after the date of receipt of the proposed revision, and a final determination by not later than 15 months after the date of publication of the revision, regarding whether the revision will— (A) improve energy efficiency in buildings, as compared to the existing model building energy code; and (B) meet the applicable targets under subsection (b)(2). (2) Codes or standards not meeting targets (A) Preliminary determination by Secretary If the Secretary makes a preliminary determination under paragraph (1)(B) that a code or standard does not meet an applicable target under subsection (b)(2), the Secretary shall contemporaneously provide to the developer of the model building energy code or standard not fewer than 2 proposed changes that would result in a model building energy code that meets the applicable target, together with supporting evidence, taking into consideration— (i) whether the modified code is technically feasible and lifecycle cost effective