WEEKLY rents in Perth have increased by 60 per cent in the past three years, almost double the average national growth, according to the latest property pulse report from RP Data. The average weekly rental rate for houses has risen 61 per cent over the past there years, reaching $391 in October 2008. Rents for units rose 62 per cent in that time to $409 a week, with the average weekly rent across all dwellings rose 60 per cent to $391. The most affordable suburbs for renting a house include Hillman ($240 a week), Orelia ($250), Parmelia ($250) and Cooloongup ($250). For units, the cheapest rents were found in Rockingham ($205), Safety Bay ($230) Bayswater ($240) and Midland ($240).