Table Of ContentElectrical Estimator's Manual
How to Estimate Electrical Construction Projects
Including Everyday Labor Installation Rates
William Penn
Houston, Texas
Copyright 0 2005 by Gulf Publishing Company, Houston, Texas. All rights reserved.
No part of this publication may be reproduced or transmitted in any form without the prior
written permission of the publisher.
Gulf Publishing Company
2 Greenway Plaza, Suite 1020
Houston, TX 77046
10 9 8 7 6 5 4 3 2 1
Printed in the United States of America.
Printed on acid-free paper.
Text design and composition by Ruth Maassen.
ISBN 0-9765113-2-0
Introduction
Th e electrical construction industry has evolved someone else) who shows responsibility, good work
from the rudimentary adage “black is the hot leg habits, dependability, and enjoys their work. The con-
and white is the neutral.” Although this is still true and tractor might encourage that employee to begin to learn
the theory is the same, much has been discovered and the estimating process; this was my personal experi-
expanded on. When you visit or speak with an electri- ence with a contractor whom I worked for as an electri-
cal contractor today about estimating, bidding, buying, cian and who led me to develop this knowledge.
etc., it is nearly the same as it was 50 years ago. Yes, the The following text has been developed after my many
estimating hardware, so to speak, has evolved from years of experience in the electrical construction indus-
handheld counters and individual wheel map measures try. The contents have been designed in such a way that
to electronic probes that count and measure and at the electrical instructors, electricians, electrical engineers,
same time keep a running total. New devices have architects, blueprint readers, etc. can draw some benefit
come into the market to make the estimating task faster from it, even if only for reference material. Those indi-
and more accurate, which, in theory, reduces the cost to viduals who have some electrical experience and want to
produce an estimate. This is all true, yet there is one advance themselves into the electrical estimators’ circle
factor that has survived all these years and will con- should study the material contained herein. The entire
tinue to survive-the hands-on ESTIMATOR. format has been designed with the beginner as well as
The ESTIMATOR has the ability to transform a set of the seasoned estimator and others in mind.
electrical construction plans and documents into a total Included are step-by-step instructions on how to
cost of labor, materials, and job expenses. All of the new interpret construction plans and specifications, what to
probes, markers, and gadgets cannot attend a prebid site look for, and why you should read all of the specifica-
investigative walk-through or actually interpret bidding tions, even those for the roofing, woodwork, wall con-
documents. This always has been, is now, and will be struction materials, plumbing, etc. Many times there
performed by a human being-an ESTIMATOR. will be items in these categories of the specifications
Estimators are constantly being sought out by elec- that impact an electrical contractor’s bidding price.
trical contractors and are in great demand. Many times Partial plans of a typical office building are in-
a contractor will have an employee (an electrician or cluded to show the utilities coming into the building,
xiv Introduction
the site lighting, interior lighting, panels and power- and installations. These have been time-tested in the
distribution devices, safety and communication devices, field and applied by many contractors whom I con-
mechanical equipment, and electrical services to prop- sulted for in the past (see “About the Author”).
erly depict the various electrical materials in place. A complete sample estimate has been included here
Rough takeoff sheets have been developed for all of to show exactly how a professional estimate is formu-
the electrical materials shown on the partial plans and lated. Although the prices of the individual materials
associated materials required for a complete installa- are not shown on the estimate pricing sheets, there
tion. This book will show you how to transfer all of the have been allowances inserted on the final recapitula-
materials shown on the rough takeoff sheets to estimat- tion sheet so that you can go through this sheet from
ing sheets for inserting prices and labor hours. The next beginning to final bidding price,
step shown is to total all of the labor (material is not At the end of this book there is a miscellaneous sec-
priced here due to each contractor’s specific pricing tion of formulas, charts, schematics, conversions, light-
structure) and transfer the hours to a final recapitula- ing levels for most common places, and blank estimat-
tion sheet. This final recapitulation sheet will include ing and related business forms.
all pricing, labor hours, nonproductive labor, job ex- There are many aspects to the electrical construc-
penses, hourly labor rates, overhead, and profit. tion industry and the feeling here is that estimating is
Following the job estimate, there is a section on the heart and soul of a successful company.
actual labor rates for thousands of items of materials
Preface
T his guide of instructional and informative material plans will lay out the services to the building, the site and
has been developed for the individual who would interior lighting, various devices, voiceldata communica-
like to add estimating of electrical construction projects to tion, the fire alarm system, and mechanical equipment
their skill set. Electrical workers, apprentices, contractors, electrical requirements.
draftspersons, engineers, architects, material handlers, The sample estimate herein includes a recapitula-
salespeople, and instructors of electrical contracting tion sheet of the sample estimate that depicts all of the
courses who are involved in the electrical construction job expenses, nonproductive labor, materials, and labor
industry can benefit by studying and applying the infor- hours for a complete installation cost. Contractor over-
mation in this guide. head as well as profit is allowed for, and these percent-
An explanation of bidding procedures, project spec- ages will be set by the contractor.
ifications, and construction plans is laid out with step- Electrical contractors are constantly searching for
by-step instructions using drawings, notations, detail qualified, experienced estimators as well as junior esti-
sheets, and a complete sample estimate. Blank esti- mators for their companies. By thoroughly studying
mating sheets for the estimator’s use when estimating this guide, you will enhance your job marketability to
are included. electrical contractors.
The guide begins by explaining the various sections A section of this guide includes more than 2,500 easily
and divisions of a sample project’s bid specifications. We accessed labor units on a wide array of electrical materi-
also review each trade’s installation responsibilities (for als, along with charts, miscellaneous formulas, and rules
example, general construction, plumbing, HVAC, and of thumb. The labor units included herein have been
electrical). Partial floor plans and site plans have been developed by this author after more than 45 years in the
developed for the electrical installation. These partial electrical construction industry (see “About the Author”).
ix
Contents
Preface ix Site Plan 5
Foundation Plans 5
About the Author xi Finish Schedule Sheet 6
Architectural Plans 6
Introduction xiii Structural Plans 6
Mechanical and Electrical Site Plans 6
CHAPTER 1 How to Estimate Electrical Plumbing Plans 6
Construction Projects 1 Heating, Ventilating, and Air-conditioning
Plans 6
Contractor’s Library: Reference Material for the
Electrical Plans 7
Estimator 1
Estimator’s Tools Required 1
CHAPTER 2 Electrical Material and Labor
Section 1: Preparing Estimates from Plans,
Specifications, and Related Documents 2 Takeoff 9
Step 1: What Documents to Look for and Typical Electrical Symbol List 9
Examine 2 Ceiling Finishes 11
Invitation to Bid 2 Text Introduction to Fixtures Takeoff 12
Form of Proposal or Bid Form 3 Text Recap of Fixtures Takeoff 12
Project Specifications 3 Text Introduction to Devices Takeoff 12
General Conditions 3 Ceiling Finishes Partial Floor Plan 13
Supplementary Conditions 3 Fixture Legend 15
Special Conditions for the Mechanical and Lighting Fixtures Partial Floor Plan 16
Electrical Trades 3 Fixtures Rough Takeoff Sheet 18
General Construction Division 3 Estimate Sheet of Fixtures Labor Hours 20
Structural Steel Division 4 Devices Partial Floor Plan 22
Plumbing Division 4 Devices Rough Takeoff Sheet 24
Heating, Ventilating, and Air-conditioning Estimate Sheet of Devices Labor Hours 25
Division 4 Text Introduction to Site Lighting Takeoff 26
Electrical Division 4 Site Lighting Partial Plan 27
Step 2: The Bid Drawings and Estimate 4 Site Lighting Rough Takeoff Sheet 29
Title Sheet 4 Estimate Sheet of Site Lighting Labor Hours 30
vi Contents
Text Introduction to Branch Wiring Takeoff 32 Field Installation of Raceways and Associated
Text Introduction to Communications Fittings for RGC 82
Takeoff 32 Field Installation of Rigid Conduit Associated
Branch Wiring Rough Takeoff Sheet 33 Fittings 84
Estimate Sheet of Branch Wiring Labor Field Installation of Rigid Conduit and
Hours 34 Associated Explosion-Proof Fittings 86
Communications Partial Floor Plan 35 Field Installation of Wireways and Fittings 88
Communications Rough Takeoff Sheet 37 Field Installation of Cable Tray and
Estimate Sheet of Communications Labor Fittings 89
Hours 38 Field Installation of Flexible Conduit and
Text Introduction to Fire Alarm Takeoff 39 Fittings 92
Text Introduction to Mechanical Equipment Field Installation of Motor Whip
Takeoff 39 Connections 93
Text Introduction to Services to Building, Field Installation of Raceways and Associated
Feeders, Panels, and Transformers 39 Fittings for EMT 94
Fire Alarm Partial Floor Plan 40 Field Installation of Raceways and Associated
Typical Fire Alarm Riser Diagram 42 PVC Fittings 95
Fire Alarm Rough Takeoff Sheet 43 Field Installation of Under Floor Ducts and
Estimate Sheet of Fire Alarm Labor Hours 44 Fittings 97
Mechanical Equipment Partial Floor Plan 45 Field Installation of Trench Duct and
Mechanical Equipment Rough Takeoff Sheet 47 Fittings 98
Estimate Sheet of Mechanical Equipment Labor Field Installation of Metal Wiremold and
Hours 48 Fittings 99
Typical Power Riser Diagram 49 Field Installation of Mineral Insulated Cable
Estimate Sheet of Panels and Transformers 600V 100
Labor Hours 50 Section 2: Devices, Boxes, Plates, and
Site Services Partial Plan 52 Flat Wiring 102
Feeder Schedule 54 Field Installation of Devices and Plates 102
Estimate Sheet of Feeders Labor Hours 55 Fie1d Ins tall a tion of Poke- Throu gh Fittings/
Typical Details Rough Takeoff Sheet 57 Devices/Covers 103
Rough Takeoff Sheets to Estimate Sheets 59 Field Installation of Sheet Metal Outlet and
Recapitulation Sheet 61 Junction Boxes 104
Estimate Sheet of Equipment Prices Field Installation of Cast Outlet and Junction
Needed 63 Boxes 105
Recapitulation of Estimate Sheets 64 Field Installation of Under Carpet Flat- Wiring
Estimate Sheets: System 106
Feeders Labor Hours 65 Section 3: Light Fixtures 107
Panels and Transformers Labor Hours 66 Field Installation of HID Lighting Fixtures 107
Indoor Feeders Labor Hours 68 Field Installation of Lighting Fixtures
Branch Wiring Labor Hours 69 (Incandescent, Exit, Emergency) 108
Site Lighting Labor Hours 70 Field Installation of Fluorescent Fixtures 109
Fixtures Labor Hours 72 Field Installation of Track Lighting
Devices Labor Hours 74 Systems 110
Communications Labor Hours 75 Field Installation of Preassembled Quick Wiring
Fire Alarm Labor Hours 76 Systems 111
Mechanical Equipment Labor Hours 77 Field Installation of Area Lighting 113
Field Installation of Wood Poles 114
Section 4: Emergency Generators 115
CHAPTER 3 Labor Rate Schedules and Forms,
Field Installation of Emergency Generator
Charts, and Diagrams 79
Sets 115
Section 1: Raceways and Fittings 82 Section 5: Grounding 117
Contents vii
Field Installation of Grounding 117 Field Installation of Multiconductor Copper
Section 6:B us Ducts 118 Cables 147
Field Installation of Copper Bus Ducts 118 Field Installation of Low-Voltage and
Field Installation of Copper Bus Ducts and Multiconductor Cables 149
Plug-in Units 119 Section 11: Voice and Data Wiring 150
Section 7: Distribution Equipment 120 Field Installation of Voice/Data Systems 150
Field Installation of Nonfused Disconnect Section 12: Miscellaneous HVAC Devices 151
Switches: 250 Volts 120 Field Installation of Wiring for Miscellaneous
Field Installation of Nema 1 Motor Control HVAC Devices 151
Centers 121 Section 13: Light Bases 152
Field Installation of Starters, Contactors, and Field Installation of Concrete Bases 152
Controls 122 Section 14: Voltage Drop Tables 153
Fiel d In stallation of High - Voltage Transformers Voltage Drop Tables for Low-Voltage
124 Circuits 153
Fiel d Installa tion of Low- Voltage Transformers Section 15: Miscellaneous 154
126 Miscellaneous Information, Formulas 154
Field Installation of Incoming Service and AC Motor Connections 155
Distribution Sections 2 28 Motor HP and Ampere Ratings
Field Installation of Meter Sockets and (Single Phase) 156
Stacks 129 Motor HP and Ampere Ratings
Field Installation of Meter Stacks 130 (Three Phase) 157
Field Installation of Indoor Surface Panel Typical Motor Control Circuits 158
Boards 131 Conversion Factors 160
Ampere Ratings of Resistance Loads (Single
Field Installation of Indoor Surface-Mounted
Panels 132 Phase) 166
Ampere Ratings of Resistance Loads (Three
Field Installation of Circuit Breakers 133
Field Connection of Preinstalled Circuit Phase) 167
BreakerdPressure Switches and Single- Wire Transformer Connections (Delta to Wye) 168
Terminations 134 Transformer Connections (Delta to Delta) 169
Transformer KVA and Ampere Ratings (Single
Field Installation of Circuit Breaker Enclosures
Phase) 170
and Circuit Breakers 136
Transformer KVA and Ampere Ratings (Three
Section 8: Fire Alarm and Miscellaneous
Phase) 171
Systems 137
Lighting Design/Footcan dle
Field Installation of Fire Alarm System
Equipment 137 Recommendations 172
Field Installation of Miscellaneous Systems 138
Section 9: Electric Heating 139 CHAPTER 4 Sample Estimate and Forms 175
Field Installation of Electric Heating 139 Estimator’s Check Sheet 176
Field Installation of Snow Melting Mats, Sample Estimate 179
Snow Melting Cable, and Heat Tracing Blank Forms 199
Cable 141 Recapitulation Sheet
Section 10: High- and Low-Voltage Cables 143 Estimate Sheet
Field Installation of High-Voltage Cable in Change Order Recapitulation Sheet
Conduit 143 Rough Takeofl Sheet
Field Installation of “Copper” Wire and Feeder Schedule
Cable 144 Request for Information
Field Installation of Multiconductor Tray Work A u tho rization Form
Cables 146 Time and Material Work Order
CHAPTER 1
How to Estimate Electrical
Construction Projects
Th is information and instructional material is de- Reference material on installations of other trades
signed for those who have experience as an electri- Pads of rough takeoff, estimate, feeder, recapitu-
cal contractor, electrician, electrical draftsperson, or lation, and change-order sheets
electrical engineer in the construction industry, and
Estimator's Tools Required
also for those who want to increase their knowledge of
the estimating field. If you have some knowledge of Triangular architect's rule
blueprint reading, electrical materials, and field instal-
Triangular engineer's rule
lations on construction projects, this material will be
Miscellaneous drafting tools (angles, protractor,
easier to learn and then apply. After you complete this
templates)
book, you will need to have access to the essential refer-
Manual hand counter
ence materials and tools that are listed below, whether
you are a beginning or a seasoned estimator. Map measuring wheels (1 inch, % inch, and M
inch to the foot)
Electronic probe counter and measurer in lieu of
Contractor's Li bray: Reference Material
manual counter and wheels
for the Estimator
Walking measuring wheel
Latest edition of the National Electrical Code
A 100-foot tape measure
Latest edition of the National Fire Prevention
Highlighter markers
Code
Access to a computer is recommended
Latest edition of the BOCA Code and local codes
in the area of construction
Estimating is the art of translating blueprints, scopes
Catalogs and digests of electrical materials
of work, prebid field inspections, and verbal requests for
Material pricing references proposals into costs of materials and labor required to
Labor unit manual for electrical materials produce a complete electrical installation with an ade-
(enclosed within Chapter 3 preferred) quate profit margin. Although there are various types of
1
2 How to Estimate Electrical Construction Projects
estimating, such as the square-foot method or the assem- A site plan and partial site services plan show the
bly method, this course will use the labor-unit ap- site lighting poles and fixtures, the wall and floor open-
proach. There may be instances where the estimator ings for the electrical service, and communications and
uses methods other than the labor-unit approach to pro- site lighting that the builder installed in the concrete
duce a budget or ballpark price. This often occurs when bearing walls below grade. Also shown are details on the
time does not allow for a labor unit estimate, but the site lighting pole bases and conduits for the service, in-
contractor feels compelled to submit a proposal to the cluding wire size, conduit size for the communications,
requesting party. These proposals are often costly to the and conduit size with wire sizes for the site lighting. The
contractor and have a negative effect on the relationship location of the temporary electric service for the project's
between both parties and perhaps others who have an construction and staging area is also shown.
interest in the project. Included in the bid package are the plans, contract
specifications including a scope of work, and a form of
SECTION 1: Preparing Estimates from Plans, proposal to be used by the bidder when submitting his
Specifications, and Related Documents or her price. The scope of work defines what is to be
included in each contractor's proposal. There is also a
For this exercise, let us assume that a shell of a 5,000-
bulletin #1 (sometimes referred to as an addendum)
square-foot (50' x 100') building has been erected for
that is to be acknowledged as received, and any cost
future office space. The floor has been poured with 4
impact must be included with the contractor's pro-
inches of reinforced concrete, the exterior walls are
posal. Bulletins and addenda often arise in response to
constructed with cement blocks, and the roofing mate-
questions of clarification asked by the contractors. This
rial is supported by steel bar joists on 4-foot centers.
method keeps all of the bidders aware of any changes in
There is a main front entrance and side and rear exit
their scope of work, which may affect their proposal.
doors. The building will be heated by natural gas and
Bulletin #1 is issued to change the bid due date only.
will be fully air-conditioned by four roof-mounted,
prepackaged HVAC units. The men's and women's rest-
STEP 1: What Documents to Look for
rooms will have a roof-mounted exhaust fan and their
and Examine
walls will be constructed of cement blocks. The entire
Invitation to Bid
building will have an automatic wet fire-sprinkler sys-
tem. The finished ceiling will be constructed with sus- The invitation may come to the bidder in the form of a
pended tee bars and acoustical ceiling tiles sized at 2' x letter, postcard, newspaper advertisement, facsimile,
4' and 2' x 2' as required. The interior walls will be steel email, or by telephone. Let us assume it was delivered
studs with sheet rock. A utility room with exposed ceil- to the bidder by letter, requesting a proposal for his or
ing construction has been provided for the electrical her portion of the work. In this case, it is for the electri-
equipment, building maintenance items, and communi- cal installation of the proposed office space. The invita-
cation space for voice and data distribution. tion usually provides a project description along with,
There are electrical floor plans that show the electri- but not limited to, other related information such as the
cal panels, lighting fixtures, switches, receptacles, ex- physical size of the building, its present condition,
haust fans, HVAC units, exit and emergency light units, location, owner, a time and date for a prebid meeting at
time clocks, fire alarm panel, fire bells, fire pull sta- the site for all the bidders (sometimes attendance is
tions, smoke detectors, telephone and data outlets, and mandatory), and a time and place to receive the bids.
detailed riser diagrams for power, fire alarm, and com- This invitation may be sufficient for the contractor to
munications systems. Most estimators will review the either submit or decline to submit a proposal. In this
electrical plans immediately and notify the various case, we will review the invitation along with the form
major material suppliers of the need for pricing and of proposal (bid form) prior to proceeding with the
the date their prices are required. decision to submit a proposal.
