The Residential Tenancies Act does not specifically address this issue. There is no sure way of preventing tenants from installing a washer and dryer in their unit. You can include a clause in the tenancy agreement that states the tenant is not allowed to install these appliances in their unit. However, if they install them anyway and damage is caused, electrical problems occur or the noise from the washer and dryer interferes with other tenants THEN you can issue a notice to terminate the tenancy using Form N5. This notice gives the tenant seven days to correct the problem. If the tenants do not comply with the notice the landlord can apply to the Landlord and Tenant Board for a hearing.