The 木造建築士試験 is a Japanese qualification exam; a 2020 guide, now a legacy document subject to review, describes 学科 I 建築計画, 学科 II 建築法規, 学科 III 建築構造, 学科 IV 建築施工 and 設計製図. The 2025 problem collection covers 学科 I and II only and states a five-option format for those booklets; it does not establish every current subject, weighting, pass mark, fee, rule or examination availability. This English knowledge preview is a knowledge check, not an exam simulation: it teaches transferable planning, regulation-arithmetic, wood-structure, drafting and integrated-judgment skills through four-option MCQs. Verify current official requirements and check current legal thresholds and procedures against applicable current law; no current rule is asserted here beyond what these documents state. Use this guide to build traceable reasoning: write formulas with units, sketch sun and airflow paths, follow structural load paths, and convert drawing scales before judging a plan. The MCQs check supporting knowledge only; they are not an official simulation, and current legal or procedural requirements must be verified separately.
What This Exam Rewards
Focus your preparation on four connected capabilities: planning, regulation arithmetic, wood structure and construction, and drawing-based judgment.
The supplied 2025 problem collection identifies 学科 I 建築計画 and 学科 II 建築法規; the supplied 2020 guide, now subject to review, also lists 学科 III 建築構造, 学科 IV 建築施工 and 設計製図. Treat that 2020 structure as legacy context rather than proof of current availability or exact format.
The practical target is not isolated trivia. A candidate must read a brief, choose plausible dimensions, test solar, ventilation and condensation logic, calculate site and form numbers, understand load paths, and communicate the result on drawings. The 2025 booklets state five-option multiple choice for 学科 I and II. This preview uses four-option MCQs only as a supporting-knowledge check; it is not a simulation and does not copy official questions.
Priority Map: Where Study Time Goes
Build calculation fluency and drawing-based error checking first; add vocabulary and legal landmarks after the core mechanisms.
High-yield areas are scale conversion, coverage and floor-area arithmetic, simple ventilation and thermal reasoning, wood shrinkage direction and load-path concepts, and stair or room dimension coordination. Medium-yield areas are room zoning, daylight geometry, symbols and notation. Lower-yield at first is memorizing isolated numbers without a context. A number is useful only when tied to a drawing, a stated condition or a check you can perform.
A productive weekly balance is two short mechanism reviews, one timed mixed set, one drawing review and one oral walk-through of a plan. Keep a correction log with three columns: what you assumed, what the drawing or data actually showed, and the stable principle that fixes it. Do not spend time trying to infer current pass marks, fees or exact weightings from this preview; the 2020 guide and 2025 booklet do not establish them.
Planning and Environment: Mechanisms and a Worked Scenario
Solar, daylight, ventilation and moisture decisions become easier when you draw the path or angle before choosing a room arrangement.
For daylight geometry, tan of the obstruction angle equals obstruction height above the reference point divided by horizontal distance. If an obstruction rises 3.0 m above a sill and stands 6.0 m horizontally from it, tan θ = 3.0/6.0 = 0.50, so θ is about 26.6 degrees. At 9.0 m, tan θ = 0.33 and θ is about 18.4 degrees. A south-facing living room benefits from lower obstruction angles, but the designer must also check summer overheating and privacy.
For ventilation, a useful path is a low inlet on the windward side and a high outlet on the leeward side, with an unobstructed route between them. If a 4.0 m by 3.0 m by 2.5 m room is checked at a hypothetical 0.5 air changes per hour, volume is 30 m³ and flow is 0.5 times 30 = 15 m³/h. For two rooms of 30 m³ and 60 m³ at the same rate, total flow is 15 plus 30 = 45 m³/h. These are arithmetic illustrations, not a legal ventilation rule.
For moisture, a thermal bridge makes an interior surface colder. If the indoor dew point is 11°C and the corner surface is 8°C, that surface is below dew point and condensation is plausible. The design response is to make insulation continuous, reduce moisture sources and provide controlled ventilation. Painting over a cold, damp corner is not a substitute for correcting the thermal and moisture balance.
Regulations Arithmetic and Building Form
Write the formula, units and limiting condition before calculating; then check the drawing against the number.
Coverage ratio equals building footprint divided by site area. A 72 m² footprint on a 180 m² site is 72/180 = 0.40, or 40%. If a hypothetical limit is 50%, the maximum footprint is 0.50 times 180 = 90 m², leaving 18 m² of unused coverage capacity. Floor-area ratio equals total floor area divided by site area. On a 200 m² site with a hypothetical 120% limit, total floor area is capped at 240 m². If 130 m² and 100 m² already exist in a two-part proposal, 230 m² is used and 10 m² remains. These calculations use only the stated numbers; do not import a current legal limit from the sample.
For form and daylight, the sun comes from the south. A building on your site shades its own north side and can shade a northern neighbour. A massing that keeps the taller portion toward the south and steps down or sets back near the north boundary is generally less obstructive to the northern neighbour than a tall wall at the north edge. For a north-facing room, the critical check is often the obstruction angle from the relevant opening, not simply the height of the building.
Fire and district questions require due diligence. If a site lies in a mapped fire-prevention district and the proposal uses exposed wood, the safe exam answer is to verify the applicable fire-resistant construction route and obtain specialist review before finalizing. Do not assume that small size, a sprinkler idea or a particular cladding automatically proves compliance. The supplied 2020 guide is legacy; current law and local interpretation must be confirmed.
Wood Structure and Construction: From Grain to Load Path
Wood is directional; connections and bracing decide whether a post-and-beam frame acts as a system.
Shrinkage is directional. Using hypothetical values for a 200 mm-wide board: tangential shrinkage of 7% gives 200 times 0.07 = 14 mm; radial shrinkage of 3% gives 6 mm; longitudinal shrinkage of 0.2% gives 0.4 mm. The tangential change dominates, which is why wide flat-grain boards can cup and why detailing should accommodate movement. Strength and stiffness are generally greatest parallel to grain for tension and compression; cross-grain bending or tension is weak and should not be treated as equivalent.
For lateral resistance, a post-and-beam frame with large openings needs a clear load path. Diagonal bracing or structural shear panels in both plan directions, continuous ties and fastened sheathing work together. Finish boards, ceilings or a few longer nails are not a substitute for a designed system. Under lateral load, the frame must transfer force from roof to foundation without soft-storey behaviour.
For foundation connection, suppose a base connection has a stated uplift of 18 kN and three bolts share it equally before safety factors: 18 divided by 3 = 6 kN per bolt. This is a conceptual share, not a design recipe; an engineer must check bolt capacity, wood embedment and concrete. If edge distance is too small, the concrete can break out at the edge. The connection must be detailed so uplift and shear reach the foundation, not merely be drawn as a bolt.
Drafting and Integrated Plan Review
Convert scale early, then use the drawing to test circulation, egress and structure together.
At 1:50, real length 4.8 m = 4800 mm; drawing length is 4800 divided by 50 = 96 mm. At 1:100, a rectangle drawn 42 mm by 36 mm represents 4200 mm by 3600 mm, or 4.2 m by 3.6 m, area 15.12 m². Always convert units before dividing. A common mistake is to divide by 5 for 1:50 or by 10 for 1:100 and then misplace the decimal.
On plans, a door leaf with a quarter-circle arc from the jamb to the opposite jamb indicates hinge side and swing direction. Check door swings against furniture, corridor width and stair approach; a symbol can be technically present but functionally wrong. Wall hatching and line weights should make structural walls, partitions and openings distinguishable without guesswork.
For integrated review, take a small two-storey house. Stack bathroom, kitchen and laundry near a service core to shorten plumbing and simplify maintenance; keep living and sleeping areas as destinations; check that the stair is reachable without passing through a wet or cooking zone. Calculate floor-to-floor rise: 2.88 m divided by 16 risers = 0.18 m = 180 mm per riser. This is arithmetic only; verify the chosen dimensions against the applicable code and the users' needs.
Common Errors and How to Catch Them
Most lost marks come from answering a nearby concept, skipping units or ignoring the drawing condition.
Planning errors include choosing a room arrangement because it is conventional while ignoring orientation, obstruction or cross-ventilation. Catch this by sketching the sun path and airflow arrows. Environment errors include confusing relative humidity with absolute humidity, or thinking heating adds moisture. If moisture is unchanged, water vapour pressure stays approximately constant while relative humidity falls as air warms.
Arithmetic errors include mixing m² with m, dividing site area by footprint, or forgetting to subtract existing area. Catch this by writing a one-line formula and carrying units. Structural errors include assuming any diagonal looks like bracing; a brace must be connected into a continuous load path. Drafting errors include using the wrong scale or trusting a symbol without checking clearance.
Integrated Practice Task and Self-Check Rubric
Use one original brief to connect planning, arithmetic, structure and drafting, then grade the process rather than a remembered answer.
Prompt: a narrow urban lot is 8.0 m wide by 20.0 m deep. The proposal is a two-storey wooden house with a footprint of 64 m². Ground floor: entry, kitchen, bath and living-dining facing south. Upper floor: two bedrooms, a small study and one stair. On a 1:100 sketch, show the site boundary, building outline, room zones, door swings, stair and main structural walls. Calculate coverage ratio, draw the cross-ventilation path and mark one thermal-bridge risk. State one connection check at the foundation. Add an obstruction rising 3.0 m above the living-room sill and 6.0 m horizontally south of it; calculate its obstruction angle.
Self-check rubric, 0 to 2 each: arithmetic, including formulas, units and coverage result; planning, including south living, service stacking and privacy; environment, including inlet and outlet path and obstruction angle; structure, including continuous bracing and foundation tie; drafting, including scale conversion, door swings, stair and line hierarchy; integrated judgment, including egress route and plumbing coordination. A score of 9 to 12 is a sound draft to revise; 5 to 8 means repeat the mechanisms; below 5 means redo the brief with one constraint at a time. This rubric evaluates your process, not official scoring.
Open-task practice for written or design components: write a one-page design note explaining your zoning, two calculations, one moisture detail and one structural load path. Then redraw the plan at 1:50 and mark every change. This is representative practice, not a simulation of the official 設計製図 task and not a substitute for current official instructions.
Study Sequence and How to Use the MCQs
Study mechanisms in short cycles, then use mixed questions to expose errors, not to rank yourself.
Week 1: planning and environment mechanisms; draw sun angles, airflow and dew-point scenarios. Week 2: coverage, floor-area arithmetic and form checks. Week 3: wood shrinkage, grain direction, bracing and foundation load paths. Week 4: scale conversion, symbols and integrated plan review. In each session, do 10 minutes of recall, 20 minutes of a worked scenario and 15 minutes of a mixed MCQ set. Review every wrong answer by writing the principle and a corrected sketch.
Use the 20 questions below as a diagnostic preview. They cover all 20 assigned items exactly once in the coverage map, but they do not cover the full syllabus. For any question involving a legal limit, current code or official procedure, treat the answer as a prompt to check the current applicable source, not as a statement that the sample's number is law. The goal is calm, traceable reasoning under time pressure.
References and further reading
Use these references to explore the concepts and check the latest information from the relevant organizations.