Written descriptive examination (記述式): boundary and area determination
Scope
The 記述式 paper is the calculation and drafting test: typically one land problem (求積, 地積測量図, 登記申請書) and one building problem (床面積, 建物図面, 区分建物).
Core rules
- 座標法: S = ½ |Σ(xᵢyᵢ₊₁ − xᵢ₊₁yᵢ)| with vertices taken in order around the parcel. Check the sign and that the list closes.
- 三斜法 splits the parcel into triangles (½ab·sin C, or ヘロン); 倍横距法 works from a reference meridian.
- 地積 is reported in ㎡ to two decimals on the 地積測量図; intermediate values are never rounded.
- The 登記申請書 needs 目的, 申請人, 原因 and its date, 添付情報 and the tax base - each a scored element.
- Building areas: 壁芯 for 一棟, 内法 for 区分建物の専有部分; verify that 専有部分 plus 共用部分 reconciles to the total.
Worked example
A parcel has vertices (0,0), (30,0), (30,40), (0,40) in metres. Products: 0·0 − 30·0 = 0; 30·40 − 30·0 = 1,200; 30·40 − 0·40 = 1,200; 0·0 − 0·40 = 0. Sum = 2,400, so S = ½ × 2,400 = 1,200 ㎡. Write 1,200.00 ㎡ and state 求積方法 = 座標法 on the 地積測量図. If the 登記記録 shows 1,180 ㎡, that gap is the trigger to check whether the 図 is newer and a 地積更正登記 is required.
Traps
- Listing vertices out of order or omitting the closing vertex.
- Rounding coordinates before multiplying.
- Omitting 求積方法 or 作成者 from the drawing.