Civil Engineering Reference
In-Depth Information
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Survey Foot
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The difference between the survey foot and international foot is small (2 parts per
million) and for most small boundary surveys the differences between the survey
foot and the international foot will not matter because measurement errors will
exceed the difference. However, when working on surveys in which measurements
may be miles in length, the differences become more important.
There have been attempts to change surveying measurements in this country
to the metric system. The metric system is commonly, almost exclusively, used
by the scientific community. During these attempts some boundary surveyors did
show both feet and meters on their plans. Showing two sets of dimensions is cum-
bersome and when you write the something twice you are twice as likely to make
a mistake. As it turned out, almost no one was interested in writing deeds with
distances measured in meters. Most boundary surveyors reverted to using feet
exclusively. The reader will have noticed that the survey foot is actually defined
in meters. However, it is still common for deeds to call out dimensions in feet.
The tradition of using feet is so well entrenched in the law of property that it will
probably require legislation before the metric system becomes widely used in this
country for boundary surveying.
4.4 Area
Area is the amount of space contained within a two dimensional geometric figure.
In the United States, area is usually measured in square feet or acres. Legend has
it that an acre was the amount of land that a yoke of oxen could plough in one day.
Today, one acre contains 43,560 square feet of land.
Consider a simple example of calculating area. A perfectly rectangular room
measures 10 feet by 12 feet. It would contain 120 square feet (10 12
=
120). In
this example, area can be thought of as the number of 1 foot square floor tiles that
would cover the floor. Note, that if the room were not rectangular, but was skewed
into a parallelogram, the area would be less.
Area in boundary surveying is always measured in the horizontal plane. A
square parcel of land measuring 100.00 feet by 100.00 feet would contain the
same area (10,000 square feet.) on a level and flat meadow as it would on a steep
mountain side. Although the actual surface area of a steep mountain side would be
substantially greater than that of the flat meadow, in boundary surveying, the area
of both are considered to be the same.
If a parcel of land contains 190,000 square feet, it could be described as
containing “4.36 acres” or “4 acres and 15,760 square feet”. For smaller parcels, con-
taining a few acres or less, acreage is often stated in square feet. For large parcels it is
usually described in decimal acres or acres with the remaining fraction in square feet.
