1.3 Legal Descriptions and Surveys
Key Takeaways
- Three accepted methods of legal description: metes-and-bounds, rectangular (government) survey, and lot-and-block (recorded plat).
- Metes-and-bounds uses a point of beginning (POB), directions, and distances, and must always return to the POB to close.
- In the rectangular survey system a section equals 1 square mile = 640 acres; a township is 6 miles square = 36 sections.
- 1 acre = 43,560 square feet — the most-tested constant in real estate math.
- A datum and benchmarks establish elevation for condominium air lots and subsurface rights.
Three Methods of Legal Description
A street address is not a legal description. The law recognizes three methods that precisely identify a parcel:
| Method | How it works | Where used |
|---|---|---|
| Metes and bounds | Boundary lines by direction (bearings) and distance, starting and ending at a point of beginning | Original 13 colonies, irregular parcels |
| Rectangular (government) survey | Grid of principal meridians (N-S) and base lines (E-W) forming townships and sections | Most states west of the Appalachians |
| Lot and block (recorded plat) | References a lot and block number on a recorded subdivision plat map | Subdivisions everywhere |
Metes and Bounds
A metes-and-bounds description begins at a point of beginning (POB), traces each boundary by compass bearing and length ("thence N 45° E, 200 feet..."), and must close by returning to the POB. A description that does not return to the POB is defective. Monuments (an iron pin, a tree, a road) may mark corners; when a monument conflicts with a stated distance, the monument generally controls.
Rectangular (Government) Survey System
Land is laid out on a grid of principal meridians (running north-south) and base lines (running east-west). The grid creates:
- Townships: 6 miles by 6 miles = 36 square miles, divided into 36 sections.
- Sections: 1 mile by 1 mile = 1 square mile = 640 acres. Sections are numbered 1–36 in a boustrophedon (back-and-forth) pattern, starting in the northeast corner.
Worked Acreage Problems
The foundational constant: 1 acre = 43,560 square feet.
Problem 1 — fractional section. How many acres is "the NW 1/4 of the SE 1/4 of Section 12"? Multiply the fractions: 1/4 × 1/4 = 1/16. Then 640 acres ÷ 16 = 40 acres.
Problem 2 — nested fraction. "The S 1/2 of the NW 1/4 of the NE 1/4." Multiply: 1/2 × 1/4 × 1/4 = 1/32. Then 640 ÷ 32 = 20 acres.
Problem 3 — lot size in square feet. A rectangular lot is 0.5 acre. How many square feet? 0.5 × 43,560 = 21,780 sq ft.
Shortcut: to read any government-survey call, read it backwards (largest unit last) and multiply all the fractional denominators, then divide 640 by that product.
A parcel is described as 'the SW 1/4 of the NE 1/4 of Section 8.' How many acres does it contain?
Lot and Block, Datum, and Air Lots
Lot and Block (Recorded Plat)
When a developer subdivides land, a plat map is recorded that divides the tract into numbered lots within numbered blocks. A deed can then describe a parcel simply as "Lot 7, Block 3, Sunrise Estates Subdivision, as recorded in Plat Book 12, Page 45." This is the simplest and most common method for residential subdivisions because the plat already contains all dimensions.
Datum, Benchmarks, and Vertical Measurement
Legal descriptions can also measure elevation. A datum is a defined point of known elevation (the U.S. Geological Survey uses mean sea level) from which heights and depths are measured. A benchmark is a permanent reference marker tied to the datum. Vertical measurement is essential for:
- Air lots — condominium units described as a volume of space above a datum.
- Subsurface rights — mineral or utility easements measured below grade.
Trap: A condominium unit's legal description is not just a floor plan; it is a three-dimensional air lot defined by elevations above the datum, plus an undivided interest in the common elements.
How many sections are in a standard township, and how many acres are in a full section?
Survey Math You Must Have Memorized
Legal-description questions are really math questions in disguise. Memorize these constants cold:
| Measurement | Equivalent |
|---|---|
| 1 acre | 43,560 square feet |
| 1 section | 1 square mile = 640 acres |
| 1 township | 36 sections = 36 square miles |
| 1 mile | 5,280 feet |
| 1 square mile | 27,878,400 square feet |
Worked Price-Per-Acre Problem
A section sells for $1,920,000. What is the price per acre, and what would the NE 1/4 cost? A full section is 640 acres, so $1,920,000 ÷ 640 = $3,000 per acre. The NE 1/4 is 1/4 × 640 = 160 acres, so 160 × $3,000 = $480,000.
Worked Lot-Dimension Problem
A builder needs a 0.25-acre lot that is 90 feet wide. How deep must it be? First convert: 0.25 × 43,560 = 10,890 sq ft. Then divide by width: 10,890 ÷ 90 = 121 feet deep. The exam expects you to move fluidly between acres and square feet using 43,560, then apply area = width × depth.
Choosing the Right Description Method
The three methods are not interchangeable in every region. A precise irregular boundary in an old colonial state usually requires metes and bounds; a quarter-section ranch in the Midwest uses the rectangular survey; and a suburban tract home almost always uses lot and block because the subdivision plat is already recorded with all dimensions and easements shown.
A single deed can even combine methods — for example, a metes-and-bounds call that begins at a monument located by reference to a section corner. When two methods in one description conflict, courts apply an order of priority that generally favors natural monuments, then artificial monuments, then courses and distances, and finally area. The takeaway for licensees: never rely on a street address alone, and always confirm the recorded legal description against the survey before contract.