Adjoining Owners Equally Responsible for Shared Fences and Boundaries Commencing January 1, 2014, adjoining landowners must share equally the responsibility for maintaining boundaries and monuments between them. Adjoining landowners are presumed to share an equal benefit from any fence dividing their properties, as well as equal costs for construction or maintenance, unless otherwise agreed in writing. This new law also provides specific procedural requirements for an owner who intends to incur costs for a division fence to notify the adjoining owner of the estimated costs and other information. Existing law enacted in 1872 which requires a homeowner who fully encloses a property to refund a neighbor a just proportion of the value of a division fence has been repealed. Assembly Bill 1404.