Chapter 31 — Exercises

These are meant to be done with a pencil and a calculator, not read. Selected answers live in Appendix J; the calculation items in Part C carry their numeric answers here in a <details> block so you can check your arithmetic without checking your reasoning.

Markup percentages, notice periods, credit rules, and whether impact costs are recoverable at all vary by contract and by jurisdiction and change over time. Every exercise states the schedule it is using; on your own job, find yours in Division 01 before you price anything.

Difficulty legend: ⭐ basic · ⭐⭐ applied · ⭐⭐⭐ judgment and synthesis · ⭐⭐⭐⭐ extension and research

Part A — Conceptual Understanding ⭐

A1. In one sentence each, define: change, change order request (COR), change order (CO), construction change directive (CCD), field order, claim. For each, say who issues it and whether you proceed on it.

A2. Name the four sources of change from §31.1 and, for each, state whose entitlement is usually strongest and what the emotional temperature of the negotiation is. Then name the one category of rework that is not a change, and say why you log it anyway.

A3. State the chapter's threshold concept in your own words in one sentence, then state its mirror image — the sentence that protects the owner rather than the contractor.

A4. Why is "we'll sign the cost now and deal with time later" described as one of the most expensive sentences in construction? Attach a dollar figure from Northgate.

A5. A field order is the architect's authority to direct a change with no cost and no time impact. Describe the failure mode, and write the two sentences of fact you would put in a same-day written response if a field order is not actually free.

A6. Explain the difference between markup and margin using the chapter's example of a subcontractor who submits "$84,000 plus 15%, total $98,824." What is the correct number, and how much does the confusion cost?

A7. Nineteen of Northgate's forty-six changes carried zero dollars. Why do those nineteen belong on the change log, and what argument do you lose if they are not there?

A8. What does a time-and-material ticket signature from the owner's representative actually mean? Quote the disclaimer language in your own words, and explain why that limitation is exactly what makes the signature obtainable.

A9. Distinguish an excusable, compensable delay from an excusable, non-compensable one, in dollars, using Northgate's rates. Why is the second only a partial win?

Part B — Applied Analysis ⭐⭐

B1. The Thursday problem. Your owner's representative directs changed work verbally at 4:50 p.m. on a Thursday with a Monday pour. You are going to proceed. List, in order, the four things you do before you go home, and name what each one is worth if you skip it. Then name the one circumstance in which you should hold the pour instead — and say who you call.

B2. Which instrument am I holding? For each document below, say what it is, whether price and time are agreed, whether you proceed, and what your very next action is. (a) An email from the architect: "Please provide a price to add card readers at four doors." (b) A letter from the owner: "Proceed immediately with the revised duct routing shown on SK-14. Pricing shall be per Article 7 on a cost-plus basis. Contract Time is not adjusted by this document." (c) A drawing returned "approved as noted" with a comment adding a second layer of board at a rated corridor. (d) A signed document from both parties adjusting the contract sum by $46,900 and silent on time.

B3. The response that is a change. The architect answers an RFI: "Provide per the equipment schedule." The mechanical drawings showed 3,000 CFM; the schedule shows 4,200 CFM; your subcontractor bid the drawing. State what has happened, what you do the same day, and what happens if you file the response and move on. Curtis Boone's version of this is a $67,000 overrun on cost code 23-00 — explain the eleven weeks.

B4. Reading a ratio. Northgate's CO #015 came to $111,273, of which $36,050 was extended general conditions for seven calendar days. Compute that as a share of the change order. Then explain to a project engineer, in plain language, why the person who prices only the work and accepts "seven days, no cost" usually feels good about the transaction.

B5. The credit conversation. Your owner deletes 320 SF of luxury vinyl tile. Your flooring subcontractor's credit is $2,048 of direct cost and they are asking for a $410 add for restocking and surplus material already ordered. Your project engineer wants to show a single net line of $1,638. Explain why that is the wrong move, and write the two lines you put on the change order instead.

B6. The sub who wants to stop work. Your electrical subcontractor performed directed work under a CCD nine weeks ago and has not been paid. Their project manager threatens to demobilize from the whole job. Before you respond, answer three questions in writing: what is your actual contractual exposure, how much of the nine weeks is your own fault, and what is the cheapest thing on the table? Then write the first two sentences you say on the phone.

Part C — Calculations and Deliverables ⭐⭐–⭐⭐⭐

Unless an exercise says otherwise, use Northgate's Division 01 change-order pricing schedule: self-perform 15% combined overhead and profit · subcontractor 15% on its own direct cost · Kestrel 5% on subcontracted work · second-tier 15% / 5% / 5% · bond and insurance 1.35% of change value applied after markups · deleted work credited at direct cost + 10% · approved time extensions at $5,150 per calendar day of extended general conditions.

C1. Price it from first principles. ⭐⭐

Meridian directs the relocation of a level-2 nurse station and the deletion of a coffee bar, replacing it with a nourishment station. Framing in the area has not started; the coffee bar millwork has not been fabricated.

Scope

• Add 46 LF of full-height metal-stud partition to the deck (12 ft), one layer of gypsum board each face, painted
• Add one 4'-0" × 7'-0" pair of hollow-metal doors, frame, and hardware
• Add 11 LF of nourishment-station casework
• Delete 22 LF of partition, not yet framed — direct cost $1,738
• Delete the coffee bar millwork, 14 LF at $310/LF direct cost, not yet fabricated

Given

Produce (a) self-perform direct cost, (b) subcontracted direct cost, (c) the credit for deleted work, (d) the marked-up total, and (e) your time position, stated the way it should appear on the change order.

C2. The cascading markup. ⭐⭐

Ardent Fire Protection subcontracts seismic bracing of the sprinkler mains to a specialty firm. The specialty firm's direct cost is $34,600.

(a) Build the price to the owner using Northgate's second-tier schedule (sub-sub 15%, first-tier 5%, Kestrel 5%, bond and insurance 1.35%). State the total load as a percentage of the actual work. (b) Recompute assuming Kestrel contracts the specialty firm directly as a first-tier subcontractor. What does that save the owner? (c) In two sentences, state what Kestrel gives up by flattening the tier — and why you would explain the arithmetic in (a) to the owner's representative before they see the number rather than after.

C3. Time, and the money attached to it. ⭐⭐

Meridian issues a CCD for a medical-gas piping revision in the ambulatory surgery suite. Kestrel's priced cost of the work, fully marked up with bond and insurance, is $88,400. Wei Chen's fragnet, inserted into the accepted current schedule update, adds 11 CD of duration to a path carrying 5 CD of float.

(a) How many calendar days do you request, and what is the extended-general-conditions value at $5,150/CD? (b) Pri Sethi offers to execute at $88,400 today if the time extension is no-cost. What is that offer actually worth, and what percentage of the change order is she asking you to donate? Write the one sentence you say in reply. (c) Now suppose the extension is granted as excusable but non-compensable. Compute your net position against Northgate's liquidated damages of $5,500/CD, and say in one sentence why this is only a partial win.

C4. The measured mile. ⭐⭐⭐

Halcyon Electric claims that 17 owner changes disrupted branch conduit and device rough-in on levels 1 and 2.

The joint scrub with Kestrel, from daily reports and the weather log, attributes: 148 MH to a two-week crew shortage Halcyon could not backfill; 96 MH to a three-day utility-tie-in shutdown that appears in the baseline schedule; 172 MH to out-of-sequence direction from Kestrel during the fire-alarm resequence. Halcyon's burdened composite rate is $68.50/MH.

(a) Compute productivity in each period and the earned hours at the unimpacted rate. (b) Compute the total loss and the portion attributable to the owner. (c) Price the change order request with markups and bond. (d) Compute the loss of efficiency as a percentage and say — in one sentence you would actually use in the meeting — what a published inefficiency table is worth here. (e) Kestrel gave back 172 hours it caused itself. Argue, in three sentences, that this made the claim stronger.

C5. The deletion that costs money. ⭐⭐⭐

In week 58, Meridian deletes a 640 SF level-3 conference room. Partitions are framed (92 LF), board is hung and taped both faces, ceiling grid is installed, one coat of paint is on, and the mechanical and electrical rough-in and devices are complete. Not yet installed: flooring, casework, AV rough-in, and door hardware.

Compute the net change order. Then write the three sentences you say when Meridian's facilities committee, which expected roughly $40,000 back, sees the number.

C6. Build the log, the aging report, and the exposure. ⭐⭐

Here is the change activity on the Willow Street Community Center as of week 44. Contract: $6,800,000, 425 CD, liquidated damages $1,200/CD, extended general conditions $1,600/CD.

(a) Produce the aging report, measured from COR submittal, in the four buckets from §31.8, and state total pending-change exposure. (b) Compute the pending schedule entitlement in days and dollars. (c) Item 009 shows a one-week gap between identification and notice. Say what that gap is worth and what you would do about it. (d) Item 015 does not appear anywhere in your aging report. Name the two documents it must appear in anyway, and write the sentence you would put in each.

Part D — Judgment and Ethics ⭐⭐⭐

D1. What the owner will bear. Your owner has a hard occupancy date six weeks out and needs a change performed immediately. Your honest, fully marked-up price is $34,000. Your assistant project manager proposes $52,000, reasoning that the owner has no alternative, will pay it, and that "they've squeezed us on everything else." Write out (a) the argument in favor, as strongly as you can make it; (b) what you actually say to your APM; and (c) the specific mechanism by which the extra $18,000 comes back out of Kestrel over the following two years. Then state the test from §31.11 in one sentence.

D2. The verbal directive as a strategy. Pri Sethi directed work verbally at 4:50 on a Thursday because she had ninety minutes and a pour on Monday. Some owner's representatives do the same thing deliberately, having learned that a contractor who proceeds without documentation can be squeezed later. (a) Name three observable tells that distinguish the second from the first. (b) Write the escalation letter you send after the third unconfirmed verbal directive — factual, non-accusatory, and impossible to ignore. (c) Explain why sending confirming letters is more important, not less, when you like and trust the person giving the direction.

D3. Choosing the mile. You are building a measured mile. Two candidate unimpacted periods exist: a four-week window with excellent productivity on an unusually simple floor plate, and an eleven-week window with ordinary productivity on work that closely matches the impacted scope. The first produces a claim roughly 40% larger. (a) Which do you choose and why? (b) Where exactly is the line between legitimate advocacy in selecting a baseline and misrepresentation? (c) Write the two sentences you would say to defend your selection to an owner's consultant who is going to attack it either way.

D4. Slow-walking. An owner's standing practice is to respond to change order requests at 60 to 90 days against a contractual 21. Nothing is denied; everything is late. (a) Quantify what that costs you on a job carrying an average $310,000 of pending, performed, unbilled change work at a 9.0% cost of money over 1.55 years. (b) Explain why this is a transfer of value nobody agreed to. (c) Name three things you can do about it that do not involve a lawyer, and one that does.

D5. The escalation you do not want to make. Your owner's representative offers to settle a $69,000 impact claim at $38,000 — but only if you also withdraw an unrelated $27,400 change order that you believe is clean and fully documented. (a) Is that a legitimate package negotiation or coercion? Argue both. (b) What does §31.7's rule about bundling say? (c) Write the reply that keeps the $38,000 on the table and takes the $27,400 out of the package.

Part M — Mixed and Interleaved Practice ⭐⭐–⭐⭐⭐

M1. Chapter 29 + Chapter 31. Meridian granted 4 of 9 claimed days on CO #14. Using the delay taxonomy, classify the 4 granted days and the 5 denied days, name the argument Meridian raised against the 5, and state the dollar consequence of each classification at Northgate's rates. Then say which single document would have moved the 5 days into the granted column.

M2. Chapter 28 + Chapter 31. Kestrel has performed $88,000 of work under a CCD that is not yet priced or approved. Show exactly how that $88,000 appears — and how it must not appear — in the monthly cost report, the cost-to-complete forecast, and the earned value calculation from Chapter 30. What does a project manager who gets this wrong spend a week explaining?

M3. Chapter 25 + Chapter 26 + Chapter 31. Take the four days of missing T&M tickets on CO #14. Design a daily-report format that would have captured the same $19,050 automatically, without anyone remembering to write a ticket. Then explain the limit of your own design: what can a daily report never prove that a signed ticket can?

M4. Chapter 16 + Chapter 19 + Chapter 31. Your prime contract gives you 14 days to notice a cost claim and 7 days to notice a time claim. Write the three flow-down provisions from §31.9 as they would appear in your subcontract, with actual day counts. Then explain what happens to you if a subcontract mirrors the prime's deadlines exactly.

M5. Chapter 13 + Chapter 31. Curtis Boone shaved his Rivermont general-conditions estimate from $1,612,000 to $1,464,000 over 610 CD without changing the duration. Compute both burn rates. Then compute what he recovered on 22 compensable days at the bid rate versus the as-built rate, and state the general principle in one sentence a bid-day reviewer would understand.

M6. Chapter 32 + Chapter 31. CO #14 executed at $142,750 in week 32. Trace it from execution to cash in Kestrel's account: which pay application, what retention applies, what lien waiver package is required, and when does the money actually arrive under Northgate's terms (pay app by the 25th, owner pays in 30 days, retention 10% until 50% complete then 5%)? Then explain why Ray traded $5,822 to reach one pay application instead of the next.

Part E — Research and Extension ⭐⭐⭐⭐

E1. Find your jurisdiction's public-works change rules. Public owners frequently regulate change orders in ways private owners do not: capped markup percentages, mandatory force-account procedures, approval thresholds that trigger a board or council vote, and statutory notice or prompt-payment requirements. Find the governing rules for one public agency where you live or work — a state department of transportation, a school district, a municipal public works department. Determine: the allowed overhead and profit percentages on changed work, whether a second tier is permitted an additional markup, the required content of a force-account record, the approval threshold above which an elected body must act, and the notice period for a differing site condition. Write a one-page memo you could hand a project team. Cite the actual documents you found; do not generalize from this book.

E2. Read a real Division 01 change-order section. Many public agencies publish complete project manuals online. Find one and read the Division 01 sections governing modification procedures and unit prices, in full. Answer: how is a change order request required to be formatted, what backup is mandatory, what happens to the request if the backup is incomplete, how are credits computed, and does the document address impact or cumulative-impact costs at all? Then compare it against the general conditions form the project uses and note every place the two documents disagree. Bring the disagreements to a colleague and ask which governs and why — that question is Chapter 7's order of precedence arriving on a real document.

E3. Read how the disruption argument is actually adjudicated. Impact and disruption are the most contested part of this chapter, and there is a substantial public record of how they get decided. Locate and read: AACE International's recommended practice on forensic schedule analysis (RP 29R-03) and its companion guidance on estimating lost labor productivity; the Society of Construction Law's Delay and Disruption Protocol; and at least two published decisions from a U.S. board of contract appeals involving a measured-mile or a total-cost disruption claim, which are freely available. Then write two pages answering one question: what distinguishes the disruption claims that were paid from the ones that were not? Compare your answer against §31.5.5 and note anything the chapter left out.