Chapter 12 Building Information Modeling 287
Cost Estimating
One of the fi rst steps in a design project is
to prepare a preliminary estimate of material
and labor costs to construct the building. The
preliminary estimate is used to obtain approval
from the client and helps in making design
decisions. Generally, the preliminary estimate
is a rough estimate of costs. Once the design has
been approved, a more accurate estimate, called
a detailed estimate, is prepared. The tools of a
BIM system help streamline this process.
A BIM model supplies all of the building data
used in cost estimating. Each object in a BIM model
has properties that identify information such
as material, type, manufacturer, part number,
and size. This information can be used to create
a material takeoff. A material takeoff is a list
of quantities of materials used in constructing
a building. A material takeoff accounts for all
building materials used in construction. For
example, each material in a 2 × 6 exterior wall
with brick veneer, including the brick, plywood
Sun
Model courtesy of Autodesk
Figure 12-9. A solar study can be used to simulate
the location and path of the sun in relation to the
home. Shown are the afternoon location of the sun
and the total sun area over a period of a year.
Goodheart-Willcox Publisher
Figure 12-10. This structural analysis shows load and strength calculations for a beam and column assembly.
Copyright Goodheart-Willcox Co., Inc.