337 Sunnyside Avenue 337 Sunnyside Ave, Ottawa, ON is a rental apartment building with 8 floorplans available. It is located in the Old Ottawa South neighborhood of Ottawa. It has apartment amenities including in-unit laundry, dishwasher, central heat, balcony, and air conditioning. It has building amenities including controlled access, and garage parking. Cats and dogs are allowed, making it a pet-friendly building.