Surveying Glossary

Most of the definitions presented below are taken in substance from "Definitions of Surveying and Associated Terms" prepared by a joint committee of the American Congress on Surveying and Mapping and the American Society of Civil Engineers, dated 1972. Presented below publication is available from the American Congress on Surveying and Mapping and other sources.

Accuracy: a degree of conformity with a standard. Accuracy relates to the quality of a result and is distinguished from precision, which relates to the quality of the operation by which the result is obtained. see Accuracy and Precision for further information

Boundary surveys: will locate visible evidence of improvements within the surveyed site and visible physical evidence of possession or occupation either way from the exterior lines of the survey with dimensions. A complete Boundary Survey will produce a drawing entitled "Plat of Survey" which can then be used for real estate closings and/or permits. Read more...

Discovery Reports: is not a survey. It is a report prepared based on site visit and research of records.. Read more...

Easement: an area of land owned by the property owner, but in which other parties, such as utility companies, may have limited rights granted for a specific purpose.

Encroachment: a structure or part of a structure that occupies the property of another.

Elevation Certificate: shows property's location, flood zone, building characteristics and the base flood elevation on a map as compared to the elevation of the property's lowest floor. Read more...

Encumbrance: an interest or partial right in real property which diminished the value of ownership but does not prevent the transfer of ownership. Mortgages, taxes, and judgments are encumbrances known as liens. Restrictions, easements, and reservations are also encumbrances, although not liens.

Error: the difference between a measured value and the true value. Error in measurement is inherent but is separate and distinct from a blunder (a mistake).

Exception: Exception from a title insurance policy, portions of the land containing encumbrances and in which free and clear title is subject to certain conditions. from a legal description, portions of land which are included in the description of a larger parcel of land but then excluded from it by a subsequent legal description.

Improvement: usually some sort of manmade structure, such as a building, garage, driveway, walkway, etc., although perhaps not always a literal "improvement".

Legal Description: a description of real estate that is sufficient to identify it for legal purposes. When preparing a deed, it is important to use the correct legal description. In most situations, the best practice is to use the legal description from the most recent deed to the property, title commitment or other purchase document. It can also be obtained from a county recorder, tax assessor, or similar official.  A new legal description for determination of title or real property rights to any portion or volume of the earth's surface, subsurface, or airspace involving the lengths and directions of boundary lines, area, parts of platted parcels or the contours the earth's surface, subsurface or airspace should be prepared by a Professional Land Surveyor. This will allow you to ensure that your description is correct and valid.

Measurement: an estimated value that is, by its nature, subject to error. A person can count (an absolute value) one hundred beans and get the same quantity as someone else counting one hundred beans. However, if two people each measure (an estimated value) a cup of beans, it is likely that they will have a different quantity of beans. Two surveyors measuring the same distance may obtain different values. Both of the values should be similar, but they will only approach the true theoretical value through repetition and statistical analysis.

Monument: object or mark placed to identify the physical location of a position. A property corner monument is often a length of an iron rod driven vertically into the ground so that the top is at or below natural grade. A cap identifying the registration number of the surveyor responsible for placing the monument may be placed atop the monument. Another surveying monument could be a cross cut in the sidewalk or pk nail often place in the alleys.

Non-Stake Survey: a Plat of Survey complying with the "Minimum Standard of practice for boundary survey." The existing substantial improvements are outlined on the plat . Existing survey monuments or monuments near the corner found during the fieldwork are flagged or painted in the field and noted on the Plat but the missing or obliterated survey monuments are not staked and the new monuments that control the boundary are not be set. Read more...

Offset: Offset in boundary: a point located at the extension of a line and marking the direction of the line. An offset monument may be placed on the extension of a line because the offset position can provide a more durable monument. A common practice is to place offset monuments in a sidewalk or curb header, as these monuments are less likely to be disturbed than a monument marking the actual position.
In construction: a short distance usually measured at a right angle to a line, to preserve the position of the line when it is anticipated that points marking the line itself would be disturbed.

Plat of Annexation: is prepared when a property is presently unincorporated, not part of a city, town, or village. The territory must be contiguous to the annexing municipality. The new boundary of the annexing municipality as described in the petition for annexation will extend to the far side of any adjacent highway and must include all of every highway within the area to be annexed. Read more...

Plat of Easement: An easement is a legal right given to another person or entity to trespass upon, or use land owned by somebody else for a specific limited purpose. Read more...

Plat of Subdivision: a legal instrument intended to take a large parcel of land and divide it into smaller parcels of land. A subdivision plat may also create public rights-of-way or easements, and is usually filed with the public real estate records of the county. Read more...

Plat of Vacation: is prepared to assist a Land Owner in "Vacating" an Easement, Right-of-Way, or other encumbrance that may no longer be needed and thereby free up the land for another use. Read more...

Precision: the degree of refinement in the performance of an operation or the degree of perfection in the instruments and methods used when making measurements. An indication of the uniformity or reproducibility of a result. Precision relates to the quality of an operation by which a result is obtained, and is distinguished from accuracy, which relates to the quality of the result. see Accuracy and Precision for further explanation.

Professional Land Surveyor: any person licensed under the laws of the State of Illinois to practice land surveying.

Right-Of-Way: a parcel of land granted by deed or easement for construction and maintenance according to a designated use. This may include highways, streets, canals, ditches, or other uses.

Staked Survey: a Plat of Survey complying with the "Minimum Standard of practice for boundary survey." The existing substantial improvements are outlined on the plat. The missing or obliterated survey monuments on accessible property corners are staked (replaced). All survey monuments found or set during the fieldwork that control the boundary are flagged or painted in the field and noted on the Plat. Read more...

Surveying or Land Surveying: the technique, profession, and science of accurately determining the terrestrial or three-dimensional position of points and the distances and angles between them commonly practiced by surveyors, and members of various engineering professions. These points are usually on the surface of the Earth, and they are often used to establish land maps and boundaries for ownership, locations like building corners or the surface location of subsurface features, or other purposes required by government or civil law, developers, homeowners for property sales, construction, site planning, land development and permits for new site improvements.

Tax Division: a process of reconfirming tax parcel boundaries. It includes both dividing and consolidating parcels as well as other actions that affect legal descriptions or geographic boundaries of tax parcels Read more...

Title Commitment/Title Insurance: a commitment to provide title insurance to a parcel of land. The surveyor is interested in the legal description and the exceptions.

Tolerance: a mathematical term indicating the allowable variation from a standard or from specified conditions. It is an indication of the accuracy and the precision of a measurement.

Wetland Delineation: Establishes the existence (location) and physical limits (size) of a wetland for the purposes of federal, state, and local regulations. Read more...

Title Commitment/Title Insurance: a commitment to provide title insurance to a parcel of land. The surveyor is interested in the legal description and the exceptions.

XYZ Coordinates: a grouping of three numbers that designate the position of a point in relation to a common reference frame. In common usage, the X and Y coordinate fix the horizontal position of the point, and Z refers to the elevation.