YamakenBlog explains how Japanese cities, building control, urban planning and property records affect real decisions and real places. The guides are written for readers who want to travel through Japan with a deeper understanding of its streets and buildings, or make informed choices about land and property.
Each article separates what public sources establish from interpretation, identifies what remains uncertain and links to the official information needed for the next step.
Historic Cities & Urban Form
Japan by rail, one urban layer at a time
Architecture and city walks from Tokyo by JR: castle towns, ports, post towns and other historic urban types, explained through geography, street plans, modern infrastructure and preservation.
Property Risk
Due diligence before a property decision
Guides to Japanese hazard information, legal controls, public records and the questions that maps alone cannot answer.
Design Tools
Yamaken Shadow Study
Compare existing and proposed building shadows, estimate direct sunlight at a point and prepare an early design report on a full-colour OpenStreetMap.
Open the Building Shadow Study and Sunlight Hours Calculator →
All English Guides
Can OpenStreetMap Building Data Support a Shadow Study?
Learn how building outlines, mapped heights, floor counts and estimates affect an OpenStreetMap-based shadow study—and what to verify.
How Many Hours of Sunlight Will My Garden Get? A Shadow Study Method
Estimate garden sunlight hours, compare seasonal dates and test a planned extension with a clear point-based shadow study method.
Existing vs Proposed Building Shadow Study: A Practical Comparison Workflow
Compare existing and proposed building shadows, read sunlight gained or lost, and document an early design decision with a practical workflow.
Matsumoto Castle Town: A Water-and-Moat Architecture Walk
Walk from Matsumoto Station through merchant streets, springs and missing moats to see how water, rail and civic preservation shaped this castle town.
Japan’s Disaster Risk Areas: What Article 39 Means Before You Buy or Rebuild
An Article 39 Disaster Risk Area can restrict rebuilding in Japan. Check the official boundary, local ordinance and your proposed work before contract.
Sendai Castle Town: Four Urban Layers on One Walk
Walk from Sendai Station to the castle to see how an Edo-period street plan, the railway and postwar reconstruction shaped the modern city.
Buying Property in Japan: What Hazard Maps Can—and Cannot—Tell You
Before you trust a color on a Japanese hazard map, find out what it shows, whether it creates a legal restriction, and which property records still matter.
About Yamaken
Yamaken is a Japan-licensed First-Class Architect, qualified building regulation conformity inspector and Real Estate Transaction Specialist. He spent more than ten years in national and local government, including building-control and urban-planning work, and now works in urban-development consulting, residential design and technical writing. Read the full profile (Japanese).