Electrical Estimating Methods

WAYNE J. DEL PICO is president of W. J. Del Pico, Inc., where he provides litigation support services and expert testimony for construction-related matters. He has more than 35-years of experience in construction project management and estimating and has been involved in projects throughout most of the United States. He is a member of the adjunct faculty at Wentworth Institute of Technology in Boston. Mr. Del Pico is a nationally recognized lecturer and author on estimating, scheduling, and project control. He is the author of Plan Reading and Material Takeoff, Estimating Building Costs, and Project Control: Integrating Cost and Schedule in Construction, and coauthor of The Practice of Cost Segregation Analysis. He is also a practicing Neutral with the American Arbitration Association, where he hears construction-related arbitration cases. More information about the author is available at www.wjdelpico.com

About the Author xiii PART 1 THE ESTIMATING PROCESS 1 CHAPTER 1 Components of an Estimate 3 CHAPTER 2 Types of Estimates 7 Order of Magnitude Estimates 8 Square Foot Estimates 9 Assemblies Estimates 10 Unit Price Estimates 11 CHAPTER 3 Before Starting the Estimate 15 Obtaining Bid Documents 15 To Bid or Not to Bid 15 Document Study 16 Estimating Team Meeting 17 CHAPTER 4 The Quantity Takeoff 19 Beginning the Quantity Takeoff 19 Rules to Follow for Accurate Takeoffs 20 Accounting for Waste 24 Other Factors that Affect Quantities 26 CHAPTER 5 Pricing the Estimate 27 Sources of Cost Data 27 Cost Categories 29 Types of Costs 29 Profit 29 CHAPTER 6 Direct Costs 31 Material 31 Labor 33 Equipment 37 Subcontractors 38 Project Overhead 40 Bonds 42 CHAPTER 7 Indirect Costs 45 Home Office Overhead 45 Profit and Contingencies 48 CHAPTER 8 The Unit Price, Project Overhead Summary, and Estimate Summary Sheets 55 Unit Price Sheet 55 Project Overhead Summary Sheet 56 The Estimate Summary Sheet 59 CHAPTER 9 Prebid Scheduling 69 Scheduling Theory 69 Critical Path Method (CPM) 70 Value of the Prebid Schedule 71 Task Types 72 Task Durations 73 Calculating Durations 74 Milestones and Constraints 76 CHAPTER 10 Bidding Strategies 77 The Business Plan 77 Competitive Bidding 78 Resource Analysis 80 Market Analysis 81 General Bidding Strategies 82 Maximizing the Profit-to-Volume Ratio 84 CHAPTER 11 Project Cost Control and Analysis 87 Cost Control 87 Productivity and Efficiency 90 Overtime Impact 91 PART 2 COMPONENTS OF ELECTRICAL SYSTEMS 93 CHAPTER 12 Raceways 95 Cable Tray 95 Conduit (to 15 High) 99 Conduit Fittings 102 Conduit in Concrete Slab 104 Conduit in Trench 105 Cutting and Drilling 106 Wire Duct Plastic 108 Trench Duct 109 Underfloor Duct 110 Surface Metal Raceways 113 Wireways 114 Flexible Metallic Conduit 116 CHAPTER 13 Conductors and Grounding 119 Wire 119 Armored Cable 123 Cable Terminations (to 600 Volt) 123 Shielded Power Cables 125 Cable Terminations (High Voltage) 126 Mineral Insulated Cable 127 Nonmetallic Sheathed Cable 128 Fiber-Optic Cable Systems 129 Special Wires 130 Grounding 131 Undercarpet Wiring 133 Undercarpet Telephone Systems 135 Undercarpet Data Systems 137 CHAPTER 14 Boxes and Wiring Devices 141 Pull Boxes and Cabinets 141 Outlet Boxes 142 Wiring Devices and Low-Voltage Switching 144 Fasteners 145 Hangers 147 CHAPTER 15 Starters, Boards, and Switches 149 Circuit Breakers 149 Control Stations 150 Fuses 151 Load Centers 153 Meter Centers and Sockets 154 Motor Control Center 155 Motor Control Center Components 157 Motor Connections 159 Motors 160 Motor Starters and Controls 161 Contactors 165 Relay 166 Panelboards 167 Panelboard Circuit Breakers 169 Safety Switches 170 Switchboards 172 Substations 174 Control Switches 176 CHAPTER 16 Transformers and Bus Duct 179 Transformers 179 Isolating Panels 180 Bus Duct 182 Bus DuctBusway 100A and Less 184 Uninterruptible Power Supply Systems 186 CHAPTER 17 Power Systems and Capacitors 187 Capacitors 187 Generator Set 188 Automatic and Manual Transfer Switches 190 CHAPTER 18 Lighting 193 Interior Lighting Fixtures 193 Exit and Emergency Lighting 196 Exterior Fixtures 197 Lamps 199 Track Lighting 200 Fixture Whips 201 CHAPTER 19 Electrical Utilities 205 Electric Site Work 205 CHAPTER 20 Special Systems 211 Special Systems 211 Clock Systems 211 Detection Systems 212 Doorbell Systems 214 Electric Heating 215 Lightning Protection 218 Nurses Call Systems 220 Closed-Circuit TV Systems 222 Residential Wiring 224 CHAPTER 21 Electrical Demolition and Temporary Facilities 229 Defining the Electrical Demolition Scope 230 Electrical Demolition 231 Temporary Facilities 232 CHAPTER 22 Contract Modifications 235 Contract Modifications 235 What Makes Change Orders Different 238 Effects of Overtime 240 CHAPTER 23 Project Closeout 243 The Closeout Process 243 Objectives of the Closeout Process 245 Contract Closeout 245 Administrative Closeout 246 Lessons Learned 246 CHAPTER 24 Computerized Estimating 249 Basic Spreadsheet Programs 250 Stand-Alone Estimating Software 252 Quantity Takeoff Software 253 APPENDIX Symbols and Abbreviations 255 Trade Specific Symbols 255 Index 265