Flat house sharing agreement Flat/house sharing agreements between tenants and other flatmates are not covered under the Residential Tenancies Act 1986. Tenants and other flatmates will, however, find it useful to have a written agreement. This is an example of what could be included in an agreement. Flat house sharing agreement Flat/house sharing agreements between tenants and other flatmates are not covered under the Residential Tenancies Act 1986. Tenants and other flatmates will, however, find it useful to have a written agreement. This is an example of what could be included in an agreement.