Construction Claims Prevention Through Accurate Estimating

Most construction claims are not won or lost in the field. They are won or lost on paper: in the estimate that defined what was included, in the notice letter that was or was not sent on time, and in the daily logs that either support the story or contradict it.

This guide covers the estimating and documentation habits that prevent disputes, and that put you in a defensible position when a dispute cannot be avoided.

Not legal advice. This article is general information for estimators and project teams. Contract rights and obligations depend on your specific contract, its governing law, and the facts. For any actual claim or dispute, consult a qualified construction attorney.

Where Claims Start in the Estimate

Three estimating problems show up again and again behind disputes:

1. Scope omissions. A missed item, such as seismic bracing for suspended MEP or firestopping at rated penetrations, becomes either a loss the contractor absorbs or an argument about whether the item was “in the documents”.
2. Undocumented assumptions. If the estimate assumed a certain sequence, access, or working hours and never said so, there is no baseline to show that conditions changed.
3. Unleveled subcontractor bids. A sub’s exclusion that nobody caught becomes a gap between the GC’s contract and the sub’s contract. Our subcontractor bid leveling guide covers how to catch these before award.

The fix is an estimate that is complete by CSI MasterFormat division (including easy-to-miss ones like 01 General Requirements, 21 Fire Suppression, and 28 Electronic Safety & Security), with a written list of inclusions, exclusions, clarifications, and assumptions. That document becomes the baseline for every later change discussion.

Notice Provisions: The Most Common Way to Lose a Valid Claim

Nearly every construction contract requires written notice of a claim, a change, or a delay within a set period after the contractor becomes aware of it. Time limits vary widely by contract form and by negotiated terms; windows of a few days to a few weeks are common. Some contracts also require a follow-up with detailed cost and schedule backup within a further period.

Courts in many jurisdictions enforce these requirements, so a contractor with a valid entitlement can still lose it by missing a notice deadline. Practical habits:

• Build a notice-provision summary for every contract at award: what triggers notice, to whom, in what form, and by when.
• Send notice when an issue first appears, even if the cost is not yet known. Notice can usually reserve rights while the impact is quantified.
• Use the delivery method the contract requires (for example, a specific address or email).
• Flow the same notice requirements down to subcontractors, with shorter windows so you can meet your own.

Daily Logs: Contemporaneous Records

Records made at the time events happen carry more weight than reconstructions made months later. A useful daily log records:

• Crew size by trade and by area, and hours worked
• Work performed and quantities installed where practical
• Equipment on site, and whether it was working or idle
• Weather, and whether it affected the work
• Deliveries, inspections, and visitors
• Directives received, especially verbal ones from the owner or design team
• Delays, interruptions, out-of-sequence work, and access problems
• Photos tied to date, location, and activity

Quantities installed per day by crew are what make productivity analysis possible later. Logs that say only “worked on level 3” are of little help.

RFIs: Documenting Questions and Answers

A request for information (RFI) is the formal record that the documents were unclear, conflicting, or incomplete, and of how the design team resolved it. For claims prevention, RFIs should:

• Reference specific sheets, details, and spec sections
• Propose a solution where possible, so the answer is faster
• State if the question may affect cost or schedule
• Be logged with dates sent, required-by, and answered

Late RFI responses are a common source of delay claims, and the RFI log is the evidence. See our RFI management guide for GCs.

Delay Types

Delay claims depend on classifying the delay correctly. The general categories used across the industry are:

Delay type	Typical cause	Time extension?	Additional compensation?
Excusable, non-compensable	Events beyond either party’s control, often unusually severe weather or other listed events	Usually yes	Usually no
Excusable, compensable	Owner-caused: late design responses, owner changes, late site access, differing site conditions (where the contract provides)	Yes	Usually yes
Non-excusable	Contractor-caused: late mobilization, poor sub performance, insufficient manpower	No	No; contractor may owe liquidated damages
Concurrent	Owner and contractor delays overlapping on the critical path	Depends on contract and jurisdiction	Often limited or apportioned

Your contract’s own definitions control. Only delays that affect the critical path (or the contract’s defined completion measure) typically support a time extension, which is why an updated CPM schedule is essential documentation.

Measured Mile: Quantifying Lost Productivity

When a disruption does not stop work but slows it down, the measured mile method is one widely used way to quantify the loss. It compares the contractor’s own productivity during an unimpacted period with productivity on similar work during the impacted period. Because it uses the project’s own data, it is generally considered more persuasive than industry-average factors.

Worked example (illustrative)

Example: an electrical contractor installs the same type of EMT conduit on two similar floors. On the first floor the work was unimpacted. On the second floor, repeated owner-directed re-routes and restricted access occurred.

Inputs from daily logs and payroll:

• Unimpacted period: 4,000 LF installed using 400 labor-hours
• Impacted period: 6,000 LF installed using 900 labor-hours
• Illustrative burdened labor rate: $85.00 per hour

Step 1: Productivity in each period

• Unimpacted: 4,000 LF / 400 LH = 10.00 LF per labor-hour
• Impacted: 6,000 LF / 900 LH = 6.67 LF per labor-hour

Step 2: Hours the impacted work should have taken at unimpacted productivity

• 6,000 LF / 10.00 LF per LH = 600 labor-hours

Step 3: Lost labor-hours

• 900 actual - 600 expected = 300 labor-hours

Step 4: Cost of lost productivity

• 300 LH x $85.00 = $25,500

Check: impacted productivity is 6.67 / 10.00 = 66.7% of unimpacted, a 33.3% loss. Equivalently, 300 lost hours / 900 actual hours = 33.3%.

For a measured mile to hold up, the two periods need to involve genuinely comparable work (same material, similar heights and access), the unimpacted period should not be affected by any contractor-caused problems, and the hours and quantities must come from contemporaneous records. Any inefficiency caused by the contractor during the impacted period should be removed from the claim.

Claims Prevention Checklist

• Estimate complete by CSI division, with written inclusions, exclusions, and assumptions
• Subcontractor bids leveled and exclusions closed before award
• Notice-provision summary prepared for each contract and subcontract
• Daily logs capturing crew, hours, quantities, weather, directives, and delays
• Photos dated and tied to location
• RFI log with sent, required-by, and answered dates
• Change order log with pricing backup (see our change order pricing guide)
• CPM schedule updated regularly, with delays documented as they occur
• Cost codes set up so impacted work can be tracked separately

Common Mistakes

• Waiting to send notice until the cost is known. Notice windows usually run from awareness of the event, not from when you finish pricing it.
• Vague daily logs. No crew sizes, no quantities, no mention of the disruption.
• Verbal directives with no written confirmation. Confirm every field directive in writing the same day.
• Mixing impacted and unimpacted cost codes. This makes measured mile analysis impossible later.
• Ignoring your own contribution. Claims that ignore contractor-caused delays or inefficiencies lose credibility.
• Estimates with no stated assumptions. Without a baseline, “changed conditions” is hard to prove.

How F&K Estimatings Can Help

F&K Estimatings builds takeoffs and estimates organized by CSI MasterFormat with scope-gap review, RFIs for unclear items, and written assumptions, so you have a clear baseline before you sign. We do not provide legal advice, but we can prepare quantity and cost backup for change orders. See our plan review service and pricing.