A designer should always be careful not to misinterpret what may seem to be an obvious property line. Furthermore, a copy of the deed can sometimes be obtained from the city or county office that records property ownership and its transfer. Property lines are legal boundaries of the site, and so their location should not be estimated. A record of a plot plan may also exist in the architect’s or building contractor’s office. Such a plot plan provides the most accurate dimensional information of all potential sources and is invaluable in making sure one is using correct information when preparing the base map and base sheet. Sometimes, the site and design proposal are simple enough not to warrant a survey. An experienced designer can often get the necessary site dimensions from both digital sources and on-site measuring (see later discussion). Accurate information is needed about the location of all existing site elements and legal restrictions like easements in order to prepare the base map and base sheet. The deed is commonly supplemented by a plot plan or site survey (see previous discussion regarding the plot plan) and is considered a legal document when it has been stamped by a registered surveyor. If the homeowner does not have a deed, the lending institution holding the mortgage on the house may have a copy in its files. Fences and hedges are often put in place by one of the homeowners on their own property, but not necessarily on or immediately adjacent to the property line. Exact location of property lines is essential. The deed is a written, legal document that transfers the title of property ownership from one party to another. Where two adjacent properties meet in a grassy yard, lawn mowers may create an identifiable line often misconstrued as a property line. Additionally, the centerline of the space between the sides of the two houses cannot be assumed to be the property line because of different setbacks.