Most mid-market commercial GCs run estimating across 3 to 8 people. The principal does the high-level review, two or three senior estimators handle the bulk of the bids, junior estimators support and shadow, and project managers occasionally pitch in on jobs they're being lined up to run. This is the structure that produces a $20M–$80M revenue commercial GC, and it is also the structure where most bid-quality variance actually lives.
The same project bid by two estimators in the same firm can come out $300K apart. Not because one is wrong and one is right — because their unit costs, their markup conventions, their typical exclusions, and their default assumptions are different. This article walks through how mid-size firms actually coordinate estimating without stepping on each other, and where the leverage is to tighten variance without slowing anyone down.
Why Multi-Estimator Coordination Is Hard
Estimating looks like math. It mostly isn't. It is judgment encoded as numbers, refined over years of bid-versus-actual feedback, and stored in the head of whoever sent the bid. When you have one estimator, that judgment is consistent by default. When you have five, you have five versions of it, and the firm doesn't have one cost library — it has five.
- Unit costs drift between estimators. Your senior carries $11/sf on mid-tier drywall. Your junior pulls $9.50 from RS Means. The same wall costs different money in your two estimates this week.
- Markup conventions vary. One estimator marks materials 18%; another marks labor 25% and materials 12%. Both produce reasonable bids; neither talks to the other; the firm has no consistent margin per project type.
- Exclusions language is personal. Each estimator has a paragraph they paste into hard-dollar bids. Some exclude weather days; others don't. Some carry mobilization; others don't. Risk distribution shifts bid to bid.
- Sub lists fragment. Each estimator has their preferred subs by trade. The firm doesn't have a sub list — it has 3-to-5 overlapping ones.
None of this kills the firm. All of it makes hit rate noisier than it should be and makes margin compression invisible until the year-end P&L lands.
The Review Cycle That Actually Works
Most firms do "second eyes" review on every bid before it goes out. Typical structure: estimator builds the bid, peer estimator reviews it for completeness, principal reviews it for fee and risk, bid goes out. The cycle takes 1–3 days. It catches obvious omissions but it misses systematic variance because reviewers default to "looks reasonable" when the bid is inside the firm's typical range.
The firms that actually compress variance run a structured review with three discrete passes.
1. Completeness pass (peer review)
Did every CSI division get a line? Are exclusions consistent with the firm's standard language? Did the bid include site logistics, permits, bonds, and insurance? This is the pass most firms do. Takes 30–60 minutes per bid.
2. Variance pass (principal or senior review)
How does this bid compare to the firm's last 3–5 bids of the same project type? Where are the largest deltas in $/sf by division, and are those deltas explainable by program differences? If Div 23 (HVAC) is 20% above the firm's running average, why? If Div 09 (finishes) is 30% below, why? Most firms don't do this pass because the data isn't structured. The firms that do run half the bid-quality variance.
3. Risk pass (principal final review)
What is the risk distribution between us and the owner? Hard-dollar lump sum puts everything on us; not-to-exceed shares the upside; T&M shares the downside. Are the assumptions explicit or buried? Are the variables (Matt's term — unknowns underground) named and priced or assumed away? This is where the firm's real margin lives.
How to Standardize Without Slowing Anyone Down
The wrong way to standardize across estimators is to mandate a software platform. Mandates fail because senior estimators have built their workflow over 25 years and any switch slows them down for 3–6 months. The right way is to standardize the inputs and let each estimator keep their workflow.
One firm-wide cost library, calibrated from actual bids
Don't ask estimators to fill out a cost library form. Read their last 3–5 bids and extract the library automatically. The library reflects what the firm actually charges, broken down by division and trade. New bids reference the library; deviations get flagged and reviewed.
Standard exclusions and inclusions language
One paragraph per project type. Not optional. Reviewed quarterly by the principal. New bids paste from the standard, edit only for project-specific scope.
Sub list, not sub lists
Single firm-wide sub list with 2–3 ranked options per trade per project size band. Updated monthly. Estimators bid against the same numbers because they're calling the same subs.
Bid-versus-actual loop
Every closed job feeds back into the cost library. Where the bid was off by more than 5% on any division, the variance is logged with a one-sentence reason. Six months of variance logs is more useful than any RS Means update.
What This Costs in Time (and What You Get Back)
| Activity | Time per Bid | Frequency |
|---|---|---|
| Completeness review (peer) | 30–60 min | Every bid |
| Variance review (principal/senior) | 20–40 min | Bids over $1M or non-standard scope |
| Risk review (principal) | 15–30 min | Every bid |
| Cost library calibration | 2–3 hours | Quarterly |
| Bid-vs-actual logging | 10–15 min | Every closed job |
The total time investment is roughly 1.5 hours per bid plus 8–12 hours per quarter on cost library and process work. The return is consistent margin per project type, lower bid-quality variance across estimators, and a cost library that doesn't die when a senior estimator leaves.
Where Software Helps (and Where It Doesn't)
Software helps with three specific parts of multi-estimator coordination: maintaining the firm-wide cost library, surfacing variance between estimators automatically, and capturing bid-versus-actual without a separate spreadsheet. Software does not help with risk review, standard exclusions language, or sub list management — those are firm-judgment work.
The trap most firms fall into is buying coordination software that mandates a workflow. Estimators reject it within 6 months. The senior estimator goes back to Excel because Excel matches how they think; the firm now has the software cost AND the divergence problem. The pattern that works is software that reads the estimator's existing files (whatever format), extracts the structured data, and surfaces variance as a report — without changing how the estimator works.
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FAQs
How much variance is normal between two estimators on the same project?
Without coordination, two estimators in the same firm typically produce bids that vary 8–15% on the same scope. With a structured cost library and review cycle, variance compresses to 3–5%. The remaining variance is real judgment differences, which is healthy.
Should the principal review every bid?
The principal should do the risk pass on every bid (15–30 minutes) and the variance pass on bids over $1M or with non-standard scope. Junior bids on standard projects can be peer-reviewed only. Mandating principal review on every bid is the most common bottleneck in mid-size firm estimating.
How do you handle sub lists when estimators have personal relationships?
Personal relationships with subs are a real asset and shouldn't be flattened. The firm-wide sub list captures who's bid in the past, what their typical pricing tier is, and how reliable their response time has been. Estimators still pick which subs to call for a given bid; the list just makes sure the firm knows what's been tried and what worked.
What's the right ratio of senior to junior estimators?
Typical mid-market commercial GC ratios are 1:1 to 1:2 senior-to-junior. Below 1:1 the senior is overloaded and review quality drops. Above 1:2 the seniors don't have time to mentor and junior ramp time stretches. The firms that maintain consistent bid quality at scale tend to cluster around 1:1.5.
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