Scale Grid

Architect Scale · 1:20

1:20 detail grid - every 25 mm cell equals 500 mm on site.

Scale Grid 25 mm pitch 1:20 12 sheet variants

About Architect Scale · 1:20

Detail-scale grid for the part of a drawing set where construction actually happens. At 1:20 a 25 mm cell represents 500 mm in the world, comfortable for window heads, junction details, stair sections and sanitary fittings. Lines are calibrated so a single A3 sheet holds an entire wall section. Further reading: A practitioner reading list covers the standards lineage in more depth.

Standards lineage

Recommended detail scale per ISO 5455:1979.

A short history

1:20 detailing standardised across British and Northern European practice in the 1960s, replacing the older 1:24 (1/2" = 1'-0") imperial detail scale.

Where designers reach for it

  • Wall-section construction details
  • Stair detail drawings
  • Window head, jamb and sill details
  • Bathroom layouts and wet-room sections

Printing this grid

Every variant on this page is delivered as a vector SVG with physical millimetre dimensions baked into the file, so a compliant printer driver will reproduce it at exact 1:1 scale by default. Choose the sheet size that matches your printer tray, set scaling to 100 % (never "fit to page"), and verify with the calibration check on our how-to-print guide. Buyer's guide: Comparing the major architectural scale rulers can help you pick the right physical scale rule to use over the printed grid.

Available sheet sizes (12)