Landlord Approval is Generally Required. A commercial sublease is a scenario where the original lessee or tenant, now the sublessor, rents out their leased space to a third party.Tenants in Washington must obtain explicit written consent from their landlord before subleasing a rental property. Edit, sign, and share Commercial Sublease - Washington online. No need to install software, just go to DocHub, and sign up instantly and for free. A Washington sublease agreement is a contract used when a tenant wants to rent part or all of their residence to another person. Subletting your office space or commercial property? Easily customize your own Commercial Sublease Agreement. Use our step-by-step builder to create a Commercial Real Estate Application.