Many people think that all surveys are the same, and that a survey is a survey is a survey. This could not be further from the truth. As mentioned in a previous post, land surveying is a diverse profession with many facets. Surveyors can be a part of many types of projects and for many different reasons. Our completed products can include different types of data and different levels of accuracy depending on the project type and budget. In this post, I will explain a few of the most common types of survey.
The most well known, if not the most common type, is the “boundary survey”. This is an “official” survey in that documents detailing the location of property boundaries and survey monuments are recorded with the county and become a part of the public record. The most common types (in California) are the “Record of Survey” and “Corner Record”. Essentially, any time a property corner is set or reset, one of these two document types must be created and submitted to the county. A record of survey is required by and governed by The State of California's Business and Professions Code, chapter 15 (Professional Land Surveyors' Act), sections 8762-8770, while corner records are governed by section 8773 (link). Boundary surveys are also required for subdivisions and lot line adjustments, but these are less common.
A second type is the topographic survey (aka “as-built” survey). These surveys document existing conditions at a particular location. They are typically required by a building or planning department as a part of a permit application, in order to clearly show the building official what the existing site conditions are and how the proposed development relates to the existing site. In many cases, an architect or engineer will commission the survey at the beginning of a project and use the survey data as the basis of their work. While these surveys will typically show boundary lines, they are not a “boundary survey” because they do not contain the information needed to retrace the boundary nor do they become a permanent public record.
The third common type is the construction survey (aka “staking” or “layout”). The purpose of this survey is to take design data (from an architect or engineer's plans) and establish positions in the real world. Items that typically require staking include utilities (water, sewer, and storm drain lines), roadways (curb, gutter, and sidewalk), the position and height of building foundations, and elevations for surface grading. This type of survey work is critically important to ensure that utilities and roadways work as intended, and to ensure that new work does not encroach on adjacent properties.
While these these three types constitute the majority of survey work, there are many other types of surveys, including:
Geodetic survey: A large scale survey that accounts for the curvature of the earths surface. Typically performed by government agencies such as the USGS or NGS.
Control survey: A relatively large survey to precisely locate a network of points, which are used to establish coordinate systems for smaller surveys in the area. This ensures that the smaller projects “tie” to each other.
Monitoring survey: Monitoring the position of an object over time to determine if any movement is occurring. Typically used during large construction projects to ensure that nearby buildings are not negatively impacted.
ALTA/NSPS survey: This is a combination of a topographic survey and boundary survey. These are usually very detailed and done to a very high level of accuracy. These are typically required by a lender or insurance company prior to sale of a commercial property. (Read more here).
Certification: There are several varieties, including FEMA flood elevation certifications, FAA 1A or 2C height certifications, or setback certifications. These demonstrate that a certain object complies with established rules.
There are other types as well, but the types listed above constitute the vast majority of survey work.
Hopefully this has been helpful and informative. If you have any questions or comments, please feel free to message me!