Whether you can rent out your house, if you have a mortgage on it, can be found in the mortgage conditions of the bank or lender. Most conditions state that you may not rent out the owner-occupied home without the permission of the mortgage provider. The lender does not have to give permission for this, every lender handles this differently.
One option may be to convert your mortgage into a rental mortgage. With a rental mortgage you have explicit permission from the lender to rent out the house. It is best to inquire with a mortgage advisor for this.