Guides

Each guide explains what a plate computes and what it does not. Read them before you use the tool, or when a plate looks odd and you want to know why. They contain the numbers we actually measured and the traps we actually fell into.

Getting started

• How to draw a site analysis diagram

  Order and principles, and which parts automation takes over.

• The panels — what to read from each

  Why the default set is composed the way it is; the questions each plate answers.

• Site overview and section — zoning limits and a 1:1 skyline cutnew

  Zoning by share of the site, the FAR and height limits each city's data carry, max floor area, the area around in numbers, and a section through the site at true vertical scale.

• Frequently asked questionsnew

  Missing buildings, gray unknowns, radius, compute times, files, SketchUp, licensing.

Sun, wind and heat

• Sun path and shadow diagrams in the browser

  How the sun-path diagram works, the 3D shadow model, changing date and hour.

• Sun hours map — a whole day of shadow in one platenew

  Shadows accumulated every ten minutes. True solar time, the criteria shown, the design we discarded, and why it is not a shadow study.

• Wind roses and urban airflow diagrams

  Sixteen-sector observed frequencies and airflow between buildings (LBM). Grid, domain, and how it differs from a wind assessment.

• Thermal comfort (UTCI) mapnew

  Weather, wind, shade and ground cover folded into a felt temperature. The 26 ft canopy assumption and the known biases.

Ground and trees

• Slope diagram — reading percent gradenew

  Bands at 5·10·15·25%, the 164 ft smoothing and what it hides, and why it is not a survey.

• Plot size diagram — urban grain from tax lotsnew

  Lot area in five bands. Where US parcels come from, the count-versus-area trap, the ownership caveat.

• Finding trees in aerial imagerynew

  NAIP near-infrared, NDVI, the offset that turned the Hudson into forest, and recall checks against the street tree records of New York (86%), Los Angeles (84.5%), San Francisco (89.2%) and Boston (86.4%).

Export and finishing

• Finishing the SVG in Illustrator

  Layer structure, recoloring, layout and print resolution, DXF.

• Exporting the 3D context model — GLB, 3DM, SKPnew

  Format differences, how the color mode carries into the file, opening in SketchUp, and which buildings are missing.

Cities

• New York City

  1,091,427 building footprints, 98.6% with year built — sample diagrams and the sources used there.

• Los Angeles

  1,097,475 building footprints, 96.0% with year built — sample diagrams and the sources used there.

• San Francisco

  162,899 building footprints, 96.2% with year built — sample diagrams and the sources used there.

• Boston

  105,587 building footprints, 96.3% with year built — sample diagrams and the sources used there.

• Washington, DC

  171,784 building footprints, 94.2% with year built — sample diagrams and the sources used there.

• Chicago

  832,475 building footprints, 96.9% with year built — sample diagrams and the sources used there.

• Miami

  72,945 building footprints, 96.2% with year built — sample diagrams and the sources used there.

• Dallas

  334,650 building footprints, 94.8% with year built — sample diagrams and the sources used there.

• Houston

  636,576 building footprints, 94.6% with year built — sample diagrams and the sources used there.

• Denver

  266,329 building footprints, 98.5% with year built — sample diagrams and the sources used there.

• Seattle

  300,350 building footprints, 97.1% with year built — sample diagrams and the sources used there.

• Minneapolis

  177,282 building footprints, 99.1% with year built — sample diagrams and the sources used there.

US datasets

• Data sources

  Every dataset behind the US edition — New York City, Los Angeles, San Francisco, Boston, Washington, DC, Chicago, Miami, Dallas, Houston, Denver, Seattle and Minneapolis — its publisher, and measured coverage.

• NYC MapPLUTO without GIS

  Tax-lot polygons with year built and land use, and how to use them.

• LA County parcels without GISnew

  The Assessor's 2.4 million parcels — use, year built, floor area — and the condominium stacks that break naive joins.

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