Rent How much apartment can I afford? What tenants pay particular attention to when looking for an apartment depends not only on the tenant's ideas - but also on whether these are realistic and feasible. A rule of thumb is that tenants should not spend more than a third of their salary on rent including heating. However, there are sometimes big differences in rental prices even within cities: some neighborhoods are more expensive than others. With the same equipment, an apartment in Frankfurt Mitte usually costs significantly more than one in Mannheim. Important points: ID card, current salary statements, creditworthiness self-disclosure, rental debt exemption certificate, questionnaire on personal information