Permissible error when surveying land plots

Establishing ownership of land involves a mandatory procedure for land surveying.

The specifics of marking boundaries are based on the use of geodetic instruments , which may provide some error.

The difficult terrain only makes the situation worse.

As a result, this can lead to serious consequences and controversial situations with the cadastral service.

The importance of defining land boundaries

Land surveying is engineering and geodetic work to establish and determine the boundaries and area of ​​the site, followed by legal registration of the relevant documents, incl. cadastral number.

From 01.01.2021, the absence of a cadastral number from the Unified State Register of Real Estate completely excludes the possibility of selling, donating or inheriting a land plot.

The documents must accurately indicate information about the boundaries of the land plot and its geometric shape.

In the absence of clearly established boundaries, the owner may have difficulties concluding legal transactions , namely:

• Division of land if it is necessary to sell, inherit or donate one of its parts;
• Purchasing land plots, especially in densely populated areas, since there is a risk of seizing someone else’s territory;
• Using land as collateral when it is necessary to obtain a loan from a bank.

In addition, there is always a risk of disputes with neighbors or the municipality regarding the appropriation of part of the territory.

Turning points

The land plot must have a certain configuration, simple or complex. The area is not always a square or rectangle with 90-degree angles - in many cases these angles can be different, which makes measurements more difficult. All places where the direction changes must be recorded - they will be called turning points.

They are easy to identify on the boundary plan, and it is by them that the position of the site is determined, and its boundaries are drawn from point to point. The cost of land surveying depends on their quantity, which means that the simpler the site is in shape, the cheaper it is to survey it. After all, to measure a simple quadrilateral, only 4 turning points are required, and if the shape of the area is more complex and it has bends, then the number of points to measure increases with each subsequent one.

Geodetic basis

Land surveying is carried out in accordance with accepted national, general and conventional coordinate systems.

In this case, reference boundary marks (RBS) serve as initial data for :

• To consolidate the local coordinate system and link it to the national one;
• Restoring lost boundary signs and solving other problems regarding the land cadastre.

Simply put, the geodetic basis for land surveying serves for surveyors to establish the boundaries of land ownership in relation to certain reference points of local or even national significance . It is on the basis of these measurements that the land plot is assigned a cadastral number.

Basic boundary markers are
points of varying degrees of national importance .
Based on these points, measurements are taken and the boundaries of the site are superimposed on the national coordinate system.

Physically, they most often look like built-in metal pipes.

The more complex the terrain of the land plot, the greater the permissible error during land surveying.

The measurement engineer's job is to accurately carry out physical calculations in accordance with the turning points marked in the digital coordinate system.

What are the coordinates of the land boundary

The main characteristic of a site is the coordinates of the site, and not the length of the boundaries.

It is the coordinates that determine the characteristics of an object in space, its position on the ground.

The coordinates provide access to the site code, its cadastral number.

The reference point for determining the coordinates of characteristic points is the reference boundary network.

To calculate the position of characteristic points and boundaries of the site, satellite, analytical, photographic, polygonometric, and cartometric methods are used.

Accuracy requirements

After designating the turning points, the boundaries of the site are drawn in the form of straight lines . Any irregularities or the presence of vegetation complicate the process of laying straight lines. The human factor and malfunction of measuring instruments cannot be ruled out.

The new calculated area and the boundaries specified on it cannot exceed the indicators specified in the cadastral document of the land plot by more than the norms established by law.

The amount of discrepancy can be reduced at the discretion of local authorities up to two times , depending on the situation in the region.

On large areas, such as agricultural land, it is quite difficult to draw the contours of the land. For this reason, there is an established permissible error rate and requirements for the accuracy of instruments.

After the study, the engineer is obliged to coordinate the boundaries with the owners of neighboring plots at a special meeting. All participants must be notified in writing. All notices are given against a personal signature.

If neighbors are absent, a notice is published in the local media. This procedure can be undertaken by the surveying company or the owner of the site.

To obtain approval, all participants in the meeting must be notified in advance that a boundary determination procedure will be carried out.

The minimum period is 30 calendar days before the measurements are taken .

The result of the work is a compiled land management file, which is transferred to the land management organization for approval of the boundary plan.

What errors can there be on the cadastral map?

This question often arises among clients when accessing a public map online. For example, how to determine whether a plot of land is located at the beginning or end of a street?

Let us clarify that the public map refers to reference resources. Accurate, up-to-date information is indicated in the USRN extract.

There are many duplicate sites on the Internet whose goal is to get money for dubious documents. There is only one official map, you can go to it from the Rosreestr website.

In life, the boundaries of the cadastral quarter do not always coincide with the boundaries of the SNT. The reason is the error of the cadastral map .

For example, our clients observed such a situation on the public cadastral map. When the background from space photographs was turned on, the area shifted by several meters.

Coordinates on paper plans or a public map may differ from the measurements of a cadastral engineer, especially when it comes to documents issued before 2010.

The reason is measurement error, the norms of which are established in legislation.

The error occurs for the following reasons:

• Features of the terrain: unevenness, ravines.
• Climatic conditions: gusts of wind, heavy precipitation, abnormal heat
• Inaccuracy of measuring instruments: untimely verification, influence of magnetic field
• Human factor: fatigue, ill health.

The error calculation is carried out on the basis of the survey justification point. It looks like this. The cadastral engineer installs the equipment at a certain point on the site. Uneven areas can cause the point to shift and increase the overall error. Therefore, in the documents this point is indicated as a survey justification point and is used for calculations.

The device, regardless of its design, distorts the readings, which may vary among different specialists.

What is error?

After taking measurements, the cadastral engineer calculates the error, which depends on :

• Characteristics of the measured territory;
• Weather conditions at the time of measurements;
• The level of training of the specialist and his work experience;
• Actual number of measurements;
• States of measuring instruments;
• Method for calculating the actual error;
• The actual distance of the site points from the OMZ.

The calculation is carried out using special formulas, one of three existing methods :

• Diagonal method;
• Permissible error method;
• Root mean square error method.

Legal regulation

The issue of land surveying is regulated by Federal Law No. 218 “On State Registration of Real Estate”, and details related to measurement methods and error calculation formulas are indicated in Order No. 90 of the Ministry of Economic Development (referenced by Article 22.13 of Federal Law No. 218).

Instructions regarding the required accuracy and permissible measurement error are also contained in the Letter of Roszemkadastre “Methodological instructions for conducting land surveying”.

In addition to those listed, there are also other legislative acts and instructions regulating the details of the land surveying procedure in general, the use of various techniques and other nuances related to land surveying and land rights. In addition to the federal level, they can also operate at the regional level. But usually all these legislative acts are of interest to the performers of the work, who will have to take them into account, and not to the owners ordering the land survey.

What maximum deviations are allowed?

Land legislation establishes the maximum permissible miscalculation when surveying land plots.

Standards are mandatory for each type of settlement and purpose of the landfill.

The permissible error when surveying land plots may vary depending on the type, category and intended purpose of the land.

Calculation examples

Let's consider a situation in which the owner of a land plot clarifies the boundaries in order to check the exact footage of the area and determine the boundaries of the land plot.

He has an extract from the state cadastre, which indicates that the maximum permissible error for a land plot measuring 663 m has reached 11.6 square meters. meters. Land surveying was carried out in 2002. After which the site was registered with Rosreestr. Since the event to clarify the boundaries, the maximum permissible standards have changed.

Engineers, when visiting the site, carried out the necessary measurements.

As a result, the difference between the land plot area according to certificates and the actual area after clarification (that is, ∆Р) reached 3.4 m. The Mt indicator for agricultural land is 0.2 m.

3.4*0.20*√663=17.5 sq. m.

The obtained result does not exceed the error standards from the cadastral extract (11.6 sq. m.).

We can conclude that the information previously recorded in the state cadastre is correct and cannot be changed in 2021. The existing error is acceptable for this category of land.

How are boundaries determined on the ground?

This process is carried out under an agreement with the customer or local administrations, private or public companies. The starting point for the activity is the drawing up of a plan that is agreed upon by all stakeholders. After this, practical work begins. To carry them out, high-tech equipment is used, which makes it possible to reduce the measurement error to almost zero. But, you need to know that the more complex and modern the devices used, the more you will have to pay for the services provided. But the absence of even the slightest errors is a very valuable factor where land is of high value or for plots of several hundred square meters, where every square centimeter counts.

The result of the measurements is a land survey, which has legal force in resolving all territorial issues.

Note: It is not allowed to change the boundaries indicated on the diagram without permission. This is subject to a large fine, which increases with repeated violations.

But, these troubles can be avoided if the change in boundaries does not exceed the permissible error when measuring land plots. Let's look at how these boundaries are formed.