The Structural Opening Estimating Calculator estimates the Material, Labour and Plant required to form large openings in walls.

The Structural Opening Estimating Calculator is linked to the Specification. Therefore, many of the items required for a structural opening are specified by the Specification.

The combination of information taken from the Specification and the dimensions you enter will calculate the following items automatically:

  • Formation of opening
  • Lintels
  • Plastering
  • Decorating


  • Please check all pre-specified items listed in the Calculated Resources tab, and in particular the red highlighted “critical items” before accepting the output.
  • You must also carefully  scrutinise the Sundry Resources tab which covers the more free form aspects of the structural opening.
  • For smaller openings, such as doorways or windows, use the Small Structural Opening Estimating Calculator.
  • For openings which require steels, use the Structural Steelwork Estimating Calculator.