Swiss rental agencies are risk-averse. They use a strict formula to decide if you can afford an apartment. Test your numbers here.
Swiss agencies strictly apply the "One-Third Rule". Check if you'll pass.
Agencies generally require that your monthly rent does not exceed **one third** of your gross monthly income. This includes "Nebenkosten" (utility charges).
If you sign the lease together (*Solidarhaftung*), you can combine your incomes. This significantly increases your budget limit.