The Replacement Fire Doors Estimating Calculator should be used to estimate the Materials, Labour and Plant required to replace an internal door with a fire door.

This Estimating Calculator is linked to the Specification. Therefore many of the items required for the door are specified from the Specification you have chosen.

The combination of resources taken from the Specification and the dimensional information will calculate the following items automatically:

  • Frame fixings
  • Plastering
  • Threshold board 
  • Decorating

To estimate the replacement of multiple doors of the same size and specification, enter the number of doors when prompted. For example, if you were estimating the replacement of two 762 wide doors into blockwork, you would enter 2. This multiplies all Materials, Labour and other associated Resources by two and subsequently doubles the cost.


  • Before accepting the output, you should check all the pre-specified items, and in particular any items that are highlighted in red to show that they are 'critical items' which are listed in the Resources Output screen.
  • In addition to the pre-specified items you must also carefully scrutinise the bottom section of the Resources Output screen. This section covers the more freeform aspects of the window such as the door type, lintel and the labour for fixing the various types of door, which are not necessarily directly linked to the dimensions you have entered.
  • This estimating calculator only replaces the door and furniture and not the door casing, architrave and any associated plastering. This can be carried out in the Replacement Door and Casing Estimating Calculator.