Part 3 · 2026 —

From cost saving to winning work

Where the accumulated data ended up was not the construction site but the bid.

In 2026, Contractor K's BIM team moved into the bid estimating department. A function that sat in the technical organization moved into the organization that wins work. That one line sums up eight years — BIM is no longer a tool for building well; it is a tool for winning work.

3.1A bid price is set by two variables

Winning work takes both bid accuracy and cost competitiveness. And the accuracy of a bid cost is, in the end, the product of two variables.

The structure of bid cost accuracy

Bid cost accuracy=Q(quantity)×P(price)

BIM group — securing Q accuracy

Self-verification with BIM at the bid stage

Removes omission and over-count risk

Estimating group — securing P competitiveness

Judging unit rates and market conditions

The estimator's own expertise

With Q accurate, the same P yields a more competitive number

Price (P) has long been the estimator's territory. What is newly secured is the accuracy of quantity (Q). Every bit of unjustified slack removed becomes headroom in the bid price.

3.2Verifying the client's bill of quantities

In general building work the contractor is chosen after design is complete, so the design documents already exist. That makes it possible to model to detailed-design level and estimate from BIM. The work here is not simply extracting quantities — it is cross-checking the bills of quantities provided by the client and the joint estimator.

BIM quantity verification at the bid stage

Bid documents received

BIM modeling · quantity take-off

· Concrete · formwork · rebar · structural steel
· Earthwork (excavation · cutoff · shoring)

Cross-check against client and joint estimator quantities

· Remove duplicated quantity
· Review over- and under-counting
· Check joint estimator human error

Gap analysis and VE value verification

· Verify VE savings

Reflected in the bid

· Bid competitiveness secured

Step 3 is the point — you do not take someone else's numbers as given; you set them beside your own model.

The ability learned in Part 1 — naming the cause of a difference — is now used on the bid, not on site.

Where drawings are sufficient, precise estimating; where they are not, conceptual estimating from the accumulated database — the two approaches are used according to the bid situation.

3.3Results

In the first half of 2026, this approach was applied to nine general building bids.

BIM verification applied

9projects

H1 2026 bids

Bid cost verified

approx. KRW 640billion

total

Quantity removed by verification

approx. KRW 5.3billion

approx. 0.8% — reflected in bid prices

By trade, BIM net quantities came in at the following levels versus conventional estimating. The gap is quantity that was riding along without justification.

By trade — BIM net quantity vs. conventional estimating(estimate = 100 · nine projects)

Concrete

approx. 98%

Formwork

approx. 97%

Rebar

approx. 96%

Structural steel

approx. 94%

↑ Estimate 100%

The gap widens toward structural steel. In other words, the harder an element is to capture with a formula — connections, for instance — the thicker the slack sitting on top of it.

Two things happened at once — the nine projects were done in-house without outsourced services, saving service fees, and bidding at the verified figures led to work actually won. It stopped being about saving cost and became about winning work.

Accumulate the data and, in the end, what you win changes.
Part 1 asked “are the quantities right?”, Part 2 “can we hold the cost ratio?”, Part 3 “can we win better than the others?” That is the range one body of data reached over eight years.

The customer and project names are anonymized, and figures are cited only from publicly announced material and within a pre-agreed scope. Diagrams and charts were newly produced from the source data.