The Walk-In Bay Window Estimating Calculators should be used to estimate the Materials, Labour and Plant required to fit walk-in bay windows.

To estimate Walk-In Bay Windows, select the Estimating Calculator containing the desired style and size of window. You will see that there are Estimating Calculators set up to estimate Standard, Horizontal Bar, Georgian Bar, Sash, Dummy Sash and Bar Dummy Sash Softwood Walk-In Bay Windows together with Standard Hardwood Walk-In Bay Windows and Standard PVCu Walk-In Bay Windows.

Once you've selected a walk-in bay window template, enter the number of windows of the same size and specification. The combination of resources taken from the specification and the dimensional information will then calculate the following items automatically:

  • Bay & Window fixings
  • Combination lintel
  • Plastering
  • Window boards
  • Decorating
  • Removal of spoil (if required)

These Estimating Calculators are linked to the Specification. 


  • The wall running above and/or beneath the window must be priced for using the standard wall estimating calculators.
  • 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 Calculated Resources tab.
  • In addition to the pre-specified items you must also carefully scrutinise the bottom section of the Sundry Resources tab. This tab covers the more freeform aspects of the bay window such as the window types and the labour for fixing the various windows, which are not necessarily directly linked to the dimensions you have entered.
  • If the size of the opening is changed you must check the suitability of the selected window, frame and lintel etc.