1.3 Legal Descriptions and Surveys
Key Takeaways
- The three legal-description methods are Metes and Bounds, Rectangular (Government) Survey, and Lot and Block (recorded plat).
- Metes and bounds starts and ends at the same point of beginning (POB); failing to close means the description is defective.
- A section is 1 mile square = 640 acres; a township is 6 miles square = 36 sections; an acre is 43,560 square feet.
- Lot and block descriptions reference a recorded subdivision plat map and are the simplest, most common method for platted urban land.
- A street address is never a legal description; benchmarks and datum are used for vertical (elevation/air-lot) measurements.
Three Methods of Legal Description
A legal description identifies a parcel precisely enough that a surveyor can locate its exact boundaries. A mailing address is never a legal description. Three accepted methods appear on the exam:
- Metes and Bounds — The oldest method. It describes the boundary by distances (metes) and directions/angles (bounds), tracing the perimeter from a fixed point of beginning (POB) around the parcel and back to that same POB. If the description does not return to the POB (does not "close"), it is defective. Uses monuments (natural or artificial markers) and compass bearings such as N 30° E.
- Rectangular (Government) Survey System — Also called the Public Land Survey System (PLSS). Uses principal meridians (run north-south) and base lines (run east-west), divided into townships and sections.
- Lot and Block (Recorded Plat) — References a lot and block number on a recorded subdivision plat map filed in the county. Simplest method; dominant for platted urban and suburban land.
Rectangular Survey: The Numbers You Must Know
The rectangular system divides land into a grid. Commit these conversions to memory:
| Unit | Size |
|---|---|
| Acre | 43,560 square feet |
| Section | 1 mile square = 640 acres |
| Township | 6 miles square = 36 sections = 23,040 acres |
| Mile | 5,280 feet |
- Townships are formed by range lines (vertical strips east/west of the meridian) and township lines (horizontal tiers north/south of the base line).
- Each township contains 36 sections, numbered 1–36 in a boustrophedonic (back-and-forth) pattern: Section 1 is the northeast corner, numbering snakes west to Section 6, drops down, and runs east again.
- A section is subdivided by halves and quarters: the NW 1/4 of a section is 160 acres; the NW 1/4 of the SE 1/4 is 40 acres.
Trap: When a description chains fractions, multiply the denominators and divide into 640.
Worked Acreage Math
Problem 1: How many acres is "the SE 1/4 of the NW 1/4 of the NE 1/4" of a section?
Multiply the fractions: 1/4 × 1/4 × 1/4 = 1/64. Then 640 ÷ 64 = 10 acres.
Shortcut: Count the quarters. Each "1/4" divides by 4, so three quarters means 640 ÷ 4 ÷ 4 ÷ 4 = 10.
Problem 2: A buyer pays $7,500 per acre for the "N 1/2 of the SW 1/4" of a section. What is the total price?
- N 1/2 of SW 1/4 = 1/2 × 1/4 = 1/8 of a section.
- 640 ÷ 8 = 80 acres.
- 80 acres × $7,500 = $600,000.
Problem 3: A rectangular lot is 220 ft × 198 ft. How many acres? 220 × 198 = 43,560 sq ft ÷ 43,560 = exactly 1 acre. Memorizing that 43,560 sq ft = 1 acre lets you size lots instantly.
A parcel is described as the "SW 1/4 of the NE 1/4" of a section. How many acres does it contain?
Surveys, Datum, and Vertical Measurement
A survey is the process of measuring boundaries and producing a legal description; a plat is the resulting map. For three-dimensional and vertical measurement (condominium air lots, subsurface rights), surveyors use:
- Datum — A defined point, line, or surface from which elevations are measured. The U.S. Geological Survey datum is mean sea level at New York Harbor.
- Benchmark — A permanent reference marker (often a brass disk) whose elevation relative to the datum is known. Surveyors run elevation measurements from the nearest benchmark.
- Air lots / subsurface lots — Condominiums create stacked legal descriptions using elevation above and below a datum so each unit's airspace is precisely defined.
Monuments (a river, a road, an iron pin) used in metes-and-bounds descriptions generally control over stated distances if the two conflict, because a fixed physical marker is considered more reliable than a transcribed measurement.
More Worked Acreage and Frontage Math
The rectangular-system questions are pure arithmetic once you trust the two memorized constants (640 acres per section, 43,560 sq ft per acre).
Problem 4 - value per section fraction: A parcel is the "NE 1/4 of the NW 1/4" of a section selling at $5,200 per acre. Acreage = 1/4 x 1/4 x 640 = 40 acres. Price = 40 x $5,200 = $208,000.
Problem 5 - mixed fractions: "The S 1/2 of the NE 1/4 and the NW 1/4 of the SE 1/4." Compute each piece, then add: S 1/2 of NE 1/4 = 1/2 x 1/4 x 640 = 80 acres; NW 1/4 of SE 1/4 = 1/4 x 1/4 x 640 = 40 acres. Total = 120 acres. The exam loves the "and" that forces you to sum two tracts.
Problem 6 - lot frontage: A rectangular lot contains 1.5 acres and has 150 feet of street frontage. What is its depth? 1.5 x 43,560 = 65,340 sq ft; 65,340 / 150 = 435.6 feet deep.
Why the Method Choice Matters
The three description methods are not interchangeable on the exam. Expect a question asking which method is used in a given scenario:
| Clue in the description | Method |
|---|---|
| Bearings, distances, monuments, "point of beginning" | Metes and bounds |
| Township, range, section, principal meridian | Rectangular (PLSS) |
| "Lot 7, Block 3, Sunset Addition" | Lot and block |
Trap: A street address or tax-parcel ID is not a legal description because it does not let a surveyor reconstruct the exact boundary. Also remember the metes-and-bounds closure rule: a description that fails to return to its point of beginning is fatally defective, and when a monument conflicts with a stated distance, the monument controls.
Which statement about legal descriptions is correct?