The preliminary ratings assigned to the residential mortgage-backed securities (RMBS) to be issued by Perpetual Trustee Co. Ltd. as trustee for Mortgage House Capital Mortgage Trust No.1 - Mortgage House RMBS Osmium Series 2024-1 reflect the following factors. The credit risk of the underlying collateral portfolio (discussed in more detail under "Credit Assessment") and the credit support provided to each class of notes are commensurate with the ratings assigned. Credit support is provided by subordination, lenders' mortgage insurance (LMI), and excess spread. Our assessment of credit risk takes into account Mortgage House of Australia Pty Ltd.'s (Mortgage House's) underwriting standards and approval process, the servicing quality of Mortgage House (discussed in more detail under "Origination And Servicing"); and the support