David is looking to rent out his residential property as a source of income whilst he plans to backpack across Wallaroo. He has recently vetted suitable lessees and through the help of his real estate agent has decided to enter into a landlord and tenant contract with Molly. The lease document describes the property in detail, outlining its status as residential, the number of rooms, square footage etc. It goes on to stipulate an agreed upon sum of $300 weekly rent, on top of electricity and gas bill coverage. The contract names David as the lessor and Molly as the lessee and states that the duration of the contract will be until David returns from his backpacking adventure.

Does the property lease contain all essential requirements, and if not what requirement/s are missing which may make it invalid?