Copyright Goodheart-Willcox Co., Inc.
Chapter 8 Building Layout 157
Pro Tip
As an alternative to the 6-8-10 method, you can use a
construction calculator or app to calculate the overall
diagonal measurement between opposing corners of a
building. To get the diagonal dimension use the “Rise”, “Run”,
“Diag” function. This dimension can also be calculated
with a standard calculator using the Pythagorean theorem,
a2 +b2 =c2. However, converting fractional feet and
inches into decimal form, then back again is cumbersome
and increases the likelihood of a math error.
8.4 Laying Out with
Leveling Instruments
In residential construction, it is important that build-
ing lines be accurately established in relation to lot
lines. It is also important that footings and foundation
walls be level, square, and the correct size.
If the building is small, such as a 24′ garage, a carpen-
ter’s level, line level, framing square, and rule are accu-
rate enough for laying out and checking the building
lines. As size increases, however, special leveling instru-
ments are needed for greater accuracy and efficiency.
8.4.1 Leveling Instruments
The builder’s level, auto level, and transit are more
accurate instruments for building layout. A laser level
is a particularly useful tool for leveling, but is not as
useful for laying out building lines. These leveling
instruments are frequently used in construction work.
Builder’s levels, auto levels, and transits are basically tele-
scopes with accurate bubble levels that must be mounted
and leveled on a base that can be rotated. When the job
is too large for the chalk line, straightedge, level, and
square, then leveling instruments should be used.
The optical device of these instruments operates on
the basic principle that a line of sight is a straight line
that does not dip, sag, or curve. Any point along a level
line of sight will be at the same height as any other
point. Through the use of these instruments, the line of
sight replaces the chalk line, line level, and straightedge.
The builder’s level, also called a dumpy level or op-
tical level, is shown in Figure 8‑6. It consists of an ac-
curate spirit level and a telescope assembly attached to
a circular base that swivels 360°. Leveling screws are
used to adjust the base after the instrument has been
mounted on a tripod. The telescope is fixed so that it
does not move up or down, but it rotates on the base.
This permits any angle in a horizontal plane to be laid
out or measured.
The auto level, Figure 8‑7, is similar to the build-
er’s level except that it contains an internal compen-
sator that eliminates any minor variant from level.
Instrument
level vial Eyepiece
Horizontal
tangent screw
Horizontal
clamp screw
Leveling screws
Horizontal
graduated circle
Lens
David White
Figure 8‑6. The builder’s level is used to sight level lines and
lay out or measure horizontal lines.
Leveling mirror Alignment sight
Focus knob
(on side
not shown)
Eyepiece
Horizontal
graduated
circle
Baseplate
Leveling screws
Bulls-eye
leveling vial
Horizontal
tangent
screw
Objective lens
Photo courtesy of Robert Bosch Tool Corporation®
Figure 8‑7. The auto level performs the same functions as a
builder’s level, but is faster and easier to set up.
Workplace Skills
Teamwork
The ability to work well in a team can make all the
difference. Whether laying out a foundation or screwing
up sheetrock, jobs that require more than one person
require teamwork. A crew that cannot work together
cannot work. Teamwork means communicating with one
another, respecting one another, and encouraging one
another. That is not to say you cannot goof-off and have
some fun occasionally. However, a good team always
knows when to put the jokes aside and kick it into gear.
When you have a job to do, you have to rely on your
team. Make sure they can rely on you too.
Chapter 8 Building Layout 157
Pro Tip
As an alternative to the 6-8-10 method, you can use a
construction calculator or app to calculate the overall
diagonal measurement between opposing corners of a
building. To get the diagonal dimension use the “Rise”, “Run”,
“Diag” function. This dimension can also be calculated
with a standard calculator using the Pythagorean theorem,
a2 +b2 =c2. However, converting fractional feet and
inches into decimal form, then back again is cumbersome
and increases the likelihood of a math error.
8.4 Laying Out with
Leveling Instruments
In residential construction, it is important that build-
ing lines be accurately established in relation to lot
lines. It is also important that footings and foundation
walls be level, square, and the correct size.
If the building is small, such as a 24′ garage, a carpen-
ter’s level, line level, framing square, and rule are accu-
rate enough for laying out and checking the building
lines. As size increases, however, special leveling instru-
ments are needed for greater accuracy and efficiency.
8.4.1 Leveling Instruments
The builder’s level, auto level, and transit are more
accurate instruments for building layout. A laser level
is a particularly useful tool for leveling, but is not as
useful for laying out building lines. These leveling
instruments are frequently used in construction work.
Builder’s levels, auto levels, and transits are basically tele-
scopes with accurate bubble levels that must be mounted
and leveled on a base that can be rotated. When the job
is too large for the chalk line, straightedge, level, and
square, then leveling instruments should be used.
The optical device of these instruments operates on
the basic principle that a line of sight is a straight line
that does not dip, sag, or curve. Any point along a level
line of sight will be at the same height as any other
point. Through the use of these instruments, the line of
sight replaces the chalk line, line level, and straightedge.
The builder’s level, also called a dumpy level or op-
tical level, is shown in Figure 8‑6. It consists of an ac-
curate spirit level and a telescope assembly attached to
a circular base that swivels 360°. Leveling screws are
used to adjust the base after the instrument has been
mounted on a tripod. The telescope is fixed so that it
does not move up or down, but it rotates on the base.
This permits any angle in a horizontal plane to be laid
out or measured.
The auto level, Figure 8‑7, is similar to the build-
er’s level except that it contains an internal compen-
sator that eliminates any minor variant from level.
Instrument
level vial Eyepiece
Horizontal
tangent screw
Horizontal
clamp screw
Leveling screws
Horizontal
graduated circle
Lens
David White
Figure 8‑6. The builder’s level is used to sight level lines and
lay out or measure horizontal lines.
Leveling mirror Alignment sight
Focus knob
(on side
not shown)
Eyepiece
Horizontal
graduated
circle
Baseplate
Leveling screws
Bulls-eye
leveling vial
Horizontal
tangent
screw
Objective lens
Photo courtesy of Robert Bosch Tool Corporation®
Figure 8‑7. The auto level performs the same functions as a
builder’s level, but is faster and easier to set up.
Workplace Skills
Teamwork
The ability to work well in a team can make all the
difference. Whether laying out a foundation or screwing
up sheetrock, jobs that require more than one person
require teamwork. A crew that cannot work together
cannot work. Teamwork means communicating with one
another, respecting one another, and encouraging one
another. That is not to say you cannot goof-off and have
some fun occasionally. However, a good team always
knows when to put the jokes aside and kick it into gear.
When you have a job to do, you have to rely on your
team. Make sure they can rely on you too.