1.3 Legal Descriptions and Surveys

Three Ways to Legally Describe Land

A legal description identifies a parcel precisely enough that a surveyor could locate it. A street address is not a legal description. Three accepted methods appear on the exam:

1. Metes and bounds — the oldest method. Uses distances (metes) and directions/boundaries (bounds), starting at a point of beginning (POB), tracing the perimeter, and returning to the POB. A description that fails to close (does not return to the POB) is defective. Boundaries are tied to monuments — natural (a river, large rock) or artificial (an iron pin, a road). Because monuments can move or vanish, this method can be imprecise.
2. Rectangular (government) survey system — also called the PLSS. Uses principal meridians (north-south) and base lines (east-west) to form a grid of townships and sections. Used in most states west of the original colonies.
3. Lot and block (recorded plat / subdivision) — references a lot and block number on a recorded subdivision map (plat) filed in the county. Most common for modern residential subdivisions; short and precise, e.g., "Lot 12, Block 4, Sunnyvale Estates, as recorded in Plat Book 9, Page 22."

Rectangular survey math (memorize these)

The grid breaks down predictably:

Worked example 1 — fractions of a section: "The NW¼ of the SE¼ of Section 10." Multiply the denominators and divide 640 by the product:

• ¼ × ¼ = 1/16 of a section
• 640 acres ÷ 16 = 40 acres

Rule of thumb: each time you read "the ¼ of the ¼," multiply the bottoms (4 × 4 = 16) and divide 640 by that number. "The S½ of the NW¼" = ½ × ¼ = 1/8 → 640 ÷ 8 = 80 acres.

Worked example 2 — square feet to acres: A rectangular lot is 217.8 ft × 200 ft. Area = 217.8 × 200 = 43,560 sq ft = 1.0 acre (because 43,560 sq ft = 1 acre). If a lot were 100 ft × 435.6 ft = 43,560 sq ft = 1 acre as well.

Reading a metes-and-bounds call and combining systems

A metes-and-bounds description reads like directions: "Beginning at the iron pin at the NE corner of Lot 7; thence S 30° E 200 feet; thence S 60° W 150 feet; thence N 30° W 200 feet; thence back to the point of beginning." Each thence is a course (direction) and distance. The description is valid only if the final call closes back to the POB. If a parcel cannot close, it is legally defective and a surveyor must correct it before title can pass cleanly.

The three systems frequently combine in one description. A subdivision plat (lot and block) is itself created by first surveying the tract using the rectangular system, and the metes-and-bounds method is used to describe irregular parcels or to set the outer boundary of a subdivision before it is platted. A reference like "Lot 4, Block 2, of the SE¼ of Section 14, Township 3 North, Range 2 East" uses both lot-and-block and rectangular survey in a single line.

Worked example 3 — combined fraction with acreage and price: A buyer purchases the "E½ of the SW¼ of the NW¼" of a section. Multiply the fractions: ½ × ¼ × ¼ = 1/32. Acreage = 640 ÷ 32 = 20 acres. At $6,500 per acre the price is 20 × $6,500 = $130,000. The exam often chains the acreage answer into a price or per-square-foot calculation, so finish the fraction first, then carry the acreage into the dollar step.

Vertical measurement: datum, benchmark, and air lots

The systems above describe the surface. To describe elevation — for a condominium unit on the 14th floor, an air lot, or subsurface rights — surveyors use vertical references:

• Datum — an established reference point of elevation (in the U.S., often the National Geodetic Vertical Datum). All height/depth measurements are figured from the datum.
• Benchmark — a permanent marker (a brass disk set in concrete) whose elevation relative to the datum is known. Surveyors run measurements from benchmarks.
• Air lot / condominium description — a parcel of airspace defined by elevations above a datum plus a horizontal boundary; this is how an upper-floor condo unit is legally described.

Do not confuse: a monument marks a horizontal boundary in metes and bounds; a benchmark marks a vertical (elevation) reference. The exam loves to swap these two terms.

What a survey does

A survey locates boundaries on the ground and is performed by a licensed surveyor. A spot survey also shows the location of improvements and any encroachments. If a fence encroaches 1.5 ft over the neighbor's line, the survey reveals it before closing — a major reason buyers and lenders order one. A legal description tells where the parcel is; the survey verifies it on the ground.