The landscapes of housing loan markets vary considerably across OECD countries, reflecting differences in preferences and policy settings. This paper first draws a topography of disparities in mortgage structure, documenting considerable variation across OECD countries in key features such as in use of fixed vs variable interest rates and typical maturities. The paper then discusses policies that can influence these outcomes. It highlights the scope for encouraging inclusive access to housing through tax-and-spending programmes that are neutral between renting and owning rather than through often very costly tax advantages for mortgage borrowing. The paper finally proposes a novel indicator to measure the balance between the rights of borrowers and lenders. Mortgage markets are deepest in countries where the index shows that creditor and borrower rights are balanced rather than severely tilted to one side.