As a general rule, a tenant is prohibited from substantially altering leased premises without the landlord`s consent. A tenant may make minor alterations to the premises. Determining what may be a minor alteration is often difficult. It is best for a tenant to get written approval from the landlord before altering the rental property. A tenant is required to return the premises in the same condition as when received, subject to normal wear and tear. If the tenant fails to return rental property in such condition, the measure of damages is the reasonable cost of restoring the premises to their original condition. In these circumstances, if the lease so provides, the landlord could retain as much of the security deposit as is necessary to return the unit to its original state. If the security deposit does not cover the full amount of the repair cost, the landlord can file suit against the tenant seeking to recover the amount spent on repairs.