Coring unit price schedule and penetration log, Aspen Station Office Building

A new unit price schedule for core drilling and sawcutting in the concrete slabs, priced by diameter range and slab depth, and a rollup of the penetration log: 1,236 penetrations and 1,223 LF of coring depth in eight slabs. With the schedule and the default assumptions, coring and sawcutting come to $213,632, which is $12,094 below the coring subcontractor's per-core quote. 38 hollow-core penetrations are carved out as a separate item.

Penetration log Rev D, exported from the coordination model Oct 28, 2026Level 1 to roof, 8 slabsPlumbing, HVAC, electrical and fire sprinklerPrices exclude sales taxPrepared Nov 5, 2026

Summary

Cost drivers

9% of the penetrations carry 27.5% of the cost

110 large penetrations in the cast-in-place slabs at Levels 1 and 2 (8 in. to 14 in. cores and sawcut openings) are 9.7% of the coring depth but $45,955 of the $167,139 for core drilling and sawcutting. Coring depth alone badly understates them.

Price by diameter range and depth, not per core or by depth alone.

Per-core quote

PT slabs cost $9,742 more at a flat price per core

Silver Basin Coring & Sawing quotes one price per core at any depth. That makes the PT slabs at Level 7 and the roof 34% more expensive than the schedule, while the 14 in. slab at Level 1 comes out $2,803 (6%) cheaper (core drilling and sawcutting).

The quote is based on slabs up to 10 in. deep. 1,009 of the 1,236 penetrations are in deeper slabs, so expect the sub to reprice them.

Hollow-core plank

38 cores need Engineer of Record approval

Per sheet S-501, 17 cores fall on a web instead of a void, 13 are within 24 in. of a bearing, 6 are within 6 in. of a plank joint and 2 are larger than 4 in. They are at Levels 3 through 6.

They are carved out of the unit price schedule as a separate item. Do not core until the EOR and the plank supplier have approved the locations in writing.

The S-501 limits and the safety notes have not been reviewed by the structural engineer of record, who should confirm they are sufficient.

Penetration log, unit prices and estimate

The controls apply to all three tabs. Click a level in the bar chart or a penetration on the plan to see its row in the penetration log and its model ID.

Safety: Scan every core and sawcut location with GPR or X-ray and mark it before cutting. Do not cut prestressing strand in hollow-core plank or tendons in PT slabs. Cores outside the S-501 limits require written approval from the Engineer of Record and the plank supplier.

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By slab

Penetrations per level, split by diameter range.

By slab type and diameter range

Level 1

Sources and method

Sources

  • Penetration_Log_Rev_D.xlsxPenetration log exported from the coordination model, sheet Penetrations, with IFC GlobalId, location, size and trade for each penetration1,236 rows
  • ASOB_Coordination_Model_2026-10-28.ifcCoordination model with plumbing, HVAC, electrical and fire sprinkler openings and a void/web check for hollow-core levels186 MB
  • S-201_Floor_Framing_Plans.pdfSlab type and depth for each level8 sheets
  • S-501_Hollow-Core_Penetration_Notes.pdfCores in voids only, 4 in. max, at least 24 in. from bearing and 6 in. from a plank joint. Anything else needs EOR and plank supplier approval2 sheets
  • Coring_Cost_Basis_2026.xlsxCalloway & Brandt Builders cost basis: setup charge, price per inch of depth by diameter range, sawcutting, adders and mobilization, October 2026 pricing3 sheets
  • Silver_Basin_Coring_Quote_2026-10-22.pdfQuote from Silver Basin Coring & Sawing LLC, one price per core by diameter range, based on slabs up to 10 in. deep3 pages
  • Subcontract_Exhibit_B_Concrete_Coring.pdfScope exhibit to the AIA A401 subcontract. Unit prices apply to added and deleted work by change order9 pages

Method

  1. The penetration log was read row by row. Slab type and depth were assigned per level from S-201.
  2. Coring depth is the slab depth at each penetration, totaled by level, slab type and diameter range. Sawcut openings count their slab depth as coring depth but are priced per linear foot per inch of depth (perimeter × depth).
  3. Hollow-core penetrations were checked against S-501: void or web from the model's check column, distance to bearing and plank joint from the coordinates, and core diameter.
  4. Unit price per core is the setup charge plus a price per inch of depth by diameter range, with adders and mobilization from the cost basis.
  5. The quote was priced with the same quantities and assumptions as the schedule.

Assumptions and limitations

  • Rebar hits are an expected share of the cores in cast-in-place and PT slabs, with a 30% adder on the core price. Hollow-core cores are drilled in voids. A tendon or strand hit is not a priced item: stop work and notify the EOR.
  • Mobilizations are counted per level: penetrations on the level divided by penetrations per trip, rounded up.
  • The 38 hollow-core penetrations outside the S-501 limits are excluded from the totals. The limits are this project's and must be confirmed against the plank supplier's requirements.
  • Factory blockouts in hollow-core plank and cast-in sleeves are not in the penetration log.
  • Firestopping, where included, is a UL-listed through-penetration system tested to ASTM E814/UL 1479 for the floor's rating, per IBC Section 714 as adopted by the AHJ.
  • Coring and sawing generate respirable crystalline silica. OSHA 29 CFR 1926.1153, Table 1 specifies integrated water delivery for rig-mounted core drills and for walk-behind and handheld saws, and a shroud with dust collection for handheld and stand-mounted drills. Tasks outside Table 1 require exposure assessment under the standard.
  • Project requirement, not a code provision: every core location in PT and hollow-core slabs is scanned with GPR or X-ray and approved before cutting.
  • The S-501 limits for hollow-core plank and the safety notes for PT and hollow-core slabs (strand and tendon hits, scanning, approval before cutting) have not been reviewed by the structural engineer of record. The EOR and the plank supplier should confirm they are sufficient before the schedule is used.
  • Unit prices, the 30% rebar adder and the mobilization charge come from the cost basis and are estimating assumptions. They have not been compared with current market prices; the estimator should check them before the schedule goes into the subcontract.