Lennie Hancock

There are many types of land surveying, employed for different purposes and using different techniques.

An archaeological field survey is an assessment of archaeological sites or finds, where their locations are plotted in a landscape. This can be done using a number of methods such as remote sensing, geophysical surveying, GPS, GIS and aerial photography, or perhaps even literary resources. Laser surveying can produce 3D computerised models of artifacts.

An ‘as-built’ survey is carried out during a construction project, or after one has been completed. It will evaluate the location of the constructed elements, and is often drawn in red or redline on an overlay. Layering an as built survey over original design plans will allow for an easy comparison of the construction progress.

A bathymetric survey will map the bed of an ocean, lake, river or other body of water. A bathymetric survey will measure the depth of the land below sea level, and is the direct opposite of a hypsometry survey, which will measure the height of land above sea level. They depth measurement is likely to be carried out with the use of sound measuring such as sonar, and global positioning (GPS) will measure this position on the earth’s surface.

Boundary surveys are likely to be carried out during the sale or purchase of land or when land is subdivided. Boundary surveys will ascertain the corners of a ‘parcel’, and may involve the setting or restoration of monuments or markers to mark these boundaries.

Deformation surveys determine and measure the change in structures and objects. They use geodetic measuring devices, geotechnical measuring devices and other techniques such as radar measuring devices. Deformation monitoring can be applied to measure the change of shape or movement of dams, roads, tunnels, mining sites, landslide and volcano slopes, settlement areas and earthquake areas over time. Laser scanning is one method which can achieve an accurate measurement of deformation.

Engineering surveys may use topographic, layout or as-built surveys, but feature more detailed data. Laser surveying is one way to achieve such accurate and detailed information.

A foundation survey is carried out to collect the positional data of construction foundations. It will be used to assess whether foundations of a structure or building have been laid at the correct depth and location.

Geological surveys are general recordings of the geologically significant features of an area. This is a general term, and can describe other types of survey.

Hydrographic surveys map the coastline and seabed, and are used in navigation and engineering.

A building survey or ‘as-built’ survey are types of measured survey, which is a general term to describe the survey done to produce plans of a building. Measured surveys can be carried out using any method of surveying, and may include laser surveying.

Mortgage surveys are also called physical surveys. They are carried out to determine land boundaries and building locations. Sometimes one of these surveys may be required before a lender will approve a mortgage loan.

A structural survey is often used by people buying a new home. Structural surveys inspect the structural stability of a building or structure, and will make note of their condition and what work may need doing.

A topographic survey marks the elevation of land, and presents these points as contour lines. These can be carried out in a number of ways including triangulation and laser surveying techniques, and may or may not include surface features such as trees and plants.

SUMO Services provide land surveying nationwide, with a comprehensive list of services. SUMO can provide measured building surveying, plan collation, utility detection and mapping and topographic surveying.