BidMagic Material Takeoff Software-- Assembly Basics

Construction Material Assembly Basics

NOTE-- We retired the BidMagic Material Takeoff Software in 2001. It has been replaced by Goldenseal Material Takeoff Software.

We still include this BidMagic estimating software manual as a convenience for users of our older program. Many features are similar, in Goldenseal estimating.

What is a Construction Material Assembly?

A material assembly is a list of all the material items that are included in a construction unit price item that is used in the BidMagic Material Takeoff Software.

EXAMPLE: The material assembly for 2x4 exterior wall framing includes 2x4 studs, 2x4's for top and bottom plates, and fasteners.

A material assembly includes the quantity of each material component, based on the number of purchase units that you 'll need to complete one unit of the construction item.

EXAMPLE: To build one lineal foot of simple 2x4 wall (16" on center), you'll need .75 precut studs for the basic stud fill, plus an additional .2 studs for a 'normal' amount of corners and headers. You will also need two lineal feet of 2x4 for double top plates, plus another one or two lineal feet of 2x4 for the bottom plate. Finally, you 'll need a small quantity (about 0.2 lbs) of standard or air-gun nails.

Each assembly also includes a waste factor for each component, to account for trimming loss, mistakes, accidental breakage, and other losses.

EXAMPLE: For framing materials, you might want to figure an 8% waste factor.

Once you've created a material assembly, it is used to calculate the material unit price-- the total material cost for one unit of the construction item.

EXAMPLE: In the case of 2x4 wall framing, one unit will be a lineal foot of framing.

To calculate the unit price, the supplier cost of each material item is multiplied by the quantity to be used (including waste factor). The individual component costs are then added together to come up with a net unit cost.

The assemblies are also used to calculate material takeoffs after you've finished a construction bid.

Material assemblies are based on the actual way you build things, so they won't change even though the price of materials changes. In fact, unless different materials are used in the future, you'll be able to use the same assemblies indefinitely to calculate the correct material unit costs for your projects.