Estimating Gross Finish Areas

The BidMagic construction estimating software calculates gross finish area (the quantity with no adjustments for windows, doors and other details).

Gross Areas

The gross areas listed on this card include the overall area of interior walls, wallboard, exterior walls, siding and finished floors. Wall openings are not subtracted from the first four measurements, and the area underneath walls is not subtracted from the finished floor area.

NOTE: Gross areas are used to figure unit prices for each category for which 'Gross Area' is checked in Preferences (see page 94).

If the quantities are locked, each of these amounts will be calculated for you, based on the measurements you've entered into previous Dimensions cards. To enter your own quantity, unlock the padlock and type it in (see page 88).

Interior Walls

This is the gross area of all interior wall surfaces. It includes the inside surface of each exterior wall, plus two surfaces on each interior wall. Openings for doors and windows are not subtracted.

• For new construction, it will include all interior walls in the project.
• For an addition, it includes all interior walls in the addition.
• For a gut/rehab, it will include all interior walls being worked on, as entered in the Basic Dimensions card.
• For a remodeling project, it includes all walls with wallboard highlighted.

Wallboard

This is the total area to be covered by wallboard or other interior finish materials. It is computed by adding the ceiling area to the interior wall area.

NOTE: The actual type of materials you will use on walls and ceilings will be covered in Specifications. Here the only thing to consider is the overall area to be covered by some kind of wall or ceiling finish.

Exterior Walls

This is the total area of all exterior walls. It includes the outside surface of each exterior wall, without subtracting for door and window openings.

Siding

This is the total gross area to be covered by siding, stucco, or some other exterior finish, without subtracting for door and window openings. It is calculated by adding together the 'triangles' under shed or gable roofs, the outside surface of any parapets, the area of any dormer walls, plus the gross exterior wall area.

NOTE: If siding will be applied to the roof side of parapets, add that extra amount to gross siding area.

Finished Floors

This is the total gross area of the building to be covered by some kind of finished floor material. Finished basements will be included, but not unfinished basements or attics. The area covered by stairways and walls is included.

• For new construction, it will include all floors in the project.
• For an addition, this quantity includes all floors in the addition.
• For a gut/rehab, it will include all floors being worked on, as entered in the Basic Dimensions card.
• For a remodeling project, it includes all floors with trim highlighted.