Bluestone Flag

Usage: Historic

Historic stone unit paver with subtle variations in color, grain, and surface. The preservation and in-kind replacement of bluestone flags are typically required in new construction projects within historic districts; the installation of new bluestone flags is typically recommended in locations adjacent to existing bluestone.

Bleecker Street, Manhattan
Sidewalk with bluestone flag


  • Reinforces historic character
  • Adds distinction and visual enhancement to sidewalk
  • Stone conveys connection to natural environment


  • Vulnerable to breakage
  • Substantially higher cost than concrete


  • This material is Standard in historic districts where LPC sidewalk regulations remain in force or other areas with existing bluestone pavers where historic fabric remains intact, per LPC guidelines


Specification source: LPC guidelines, DOT Standard Specifications Section 6.07

  • Bluestone: minimum 2.25-inch thick New York State bluestone to match size and color of existing flags Finish: Thermal
  • Joints: Hand-tight
  • Sustainability opportunity: Salvaged bluestone


  • In historic districts, adjacent property owners are generally responsible for maintaining this material
  • Use of this material outside historic districts requires a maintenance agreement
  • Due to the possibility of bluestone pavers cracking or becoming uneven, application requires attentive maintenance
  • Wherever possible, existing material should be salvaged and reused
  • Bluestone-tinted concrete can be used to fill gaps when recycling existing bluestone flags
  • All sidewalk repair or replacement in historic districts requires written approval from LPC
  • Repairs and maintenance are more complex and require more highly-skilled labor