An estimate review is an audit of a document you already own — a subcontractor's bid, an in-house takeoff, or a budget from another firm. You send the estimate, the plans and specifications it was priced from, and the addenda that changed the scope. We do not produce a parallel estimate from scratch. We re-measure the quantities that drive the number, test the unit rates against ZIP-code-adjusted material and labor pricing, and mark every variance on the plan set so you can see where the number holds and where it does not.
- Deliverable
- Excel estimate + marked-up PDF plans
- Organized by
- CSI MasterFormat section
- Turnaround
- 24–48 hours for most projects
- Pricing
- ZIP-code-adjusted material and labor pricing
- Software
- Bluebeam Revu, PlanSwift, RSMeans data
You need this review when you are about to sign a GMP, submit a hard bid, or award a subcontract and the number has to survive scrutiny. It is also the right first step when you want a second opinion construction estimate, or when you are comparing two estimates that differ by more than the scope should explain. The construction estimate audit covers all CSI MasterFormat divisions present in the reviewed estimate, most often Division 03 concrete, Division 05 metals, Division 09 finishes, Division 22 plumbing, Division 23 HVAC, Division 26 electrical, and Division 31 earthwork.
Our takeoff is organized by CSI MasterFormat division in Excel and PDF, with the marked-up plan set attached. Quantities are shown with the unit of measure and the drawing reference, so your estimator can trace any line back to its source. We work in Bluebeam Revu, PlanSwift and RSMeans data, and we can reconcile the audit against a Uniformat or cost breakdown structure view when your budget is organized that way. If you need the full estimate rebuilt instead of audited, start with Construction Estimating Services. If the review shows the number is short, we can follow with a Budget Estimating Services update or a Bid Estimating Services reprice before your deadline.
What the construction estimate audit covers
We audit the estimate as a document, not as a set of opinions. Every quantity is re-measured from the drawings, every unit rate is compared to the pricing basis stated in the estimate, and every omission is tied to the sheet or spec section where it should have appeared. The output is a variance schedule and a marked-up set, not a replacement estimate.
Concrete & Formwork Audit
Re-measure concrete volume by mix and placement method, formwork contact area, and reinforcing steel weight with lap and waste.
CY · SF · TONSteel & Deck Review
Verify structural steel tonnage including connections and metal deck, and check fabrication and erection rates against local pricing.
TON · SFFinishes & Envelope
Audit exterior wall assembly area by substrate and finish, gypsum board by type and level, and roofing squares with membrane and flashing.
SF · SQMechanical & Plumbing
Check ductwork weight or area by gauge and pressure class, and pipe and fittings with hangers and insulation against the specification.
LB · LF · EAElectrical & Systems
Re-measure wire and conduit runs by raceway type and conductor size, and verify home-run lengths and device counts from the drawings.
LF · EASitework & Earthwork
Audit cut and fill volumes with shrink and swell factors applied, and check erosion control and utility trench quantities.
CY · LFGeneral Conditions & Markups
Review overhead, profit, bond, insurance, and escalation percentages for consistency with the project duration and contract type.
% · LSPlan Markup & Traceability
Deliver a marked-up plan set and Excel backup showing every quantity, unit rate, and drawing reference for your team to trace.
PDF · XLSXWhat every estimate review & second-opinion audit takeoff includes
- Re-measure of concrete volume by mix and placement method (CY)
- Formwork contact area (SF) separated from concrete volume
- Reinforcing steel weight (TON) with lap and waste
- Structural steel tonnage (TON) including connections and deck
- Exterior wall assembly area (SF) by substrate and finish
- Gypsum board area (SF) by board type and level of finish
- Roofing area (SQ) with membrane, insulation, and flashing
- Ductwork weight or area (LB or SF) by gauge and pressure class
- Pipe and fittings (LF and EA) with hangers and insulation
- Wire and conduit runs (LF) by raceway type and conductor size
- Door and hardware count (EA) from the hardware schedule
- Earthwork cut/fill (CY) with shrink and swell factors applied
How we run a bid estimate review
- Document intake and scope lockWe log the estimate version, the drawing set date, and the spec sections you send. We confirm the scope the estimate claims to cover — base bid, alternates, allowances, unit prices — and note any exclusions the original estimator stated. This becomes the baseline for the variance schedule, so nothing is flagged as missing if it was never in scope.
- Quantity re-measure by divisionWe re-measure the dominant quantities from the drawings: concrete by placement (footings, walls, slab-on-grade, elevated slab) in CY, formwork contact area in SF, rebar in TON with lap and waste, structural steel in TON, gypsum board in SF by level of finish, ductwork in LB by gauge and pressure class, and pipe in LF by material and size. Each quantity is tagged to the sheet it came from.
- Unit-rate comparisonWe compare the unit rates in the estimate to ZIP-code-adjusted material and labor pricing for the project location. Concrete mix design price per CY, structural steel per TON, gypsum board per SF by level of finish, ductwork per LB by gauge, and pipe per LF by material are the lines that move the total most. Rates that fall outside a reasonable band are flagged with the basis we used.
- Scope-gap sweepWe walk the drawings and specs against the estimate line by line to find work that is shown but not priced: pipe hangers and seismic bracing in Division 22, duct insulation and pressure-class gauge adjustments in Division 23, home-run conduit lengths beyond the panel schedule in Division 26, and roof insulation thickness taken from the detail instead of the spec. Each gap is tied to the sheet or section where it appears.
- Variance schedule and marked-up setWe produce an Excel variance schedule showing the original quantity, our re-measured quantity, the difference, and the unit rate used for each. The marked-up plan set shows where each variance was measured. The PDF summary ranks variances by dollar impact so you can see which lines decide whether the number is trustworthy.
- Quality check and deliveryA senior estimator reviews the variance schedule against the marked-up set to confirm every re-measured quantity traces to a drawing reference and every unit rate matches the ZIP-adjusted basis. We check that all divisions present in the original estimate are accounted for, and that any division we could not audit is listed with the reason. The final package is delivered in Excel and PDF within 24–48 hours of receiving complete documents.
What we need from you
- Current estimate fileExcel or PDF with quantities and unit rates visible. If the estimate is a lump sum only, tell us which divisions you want audited first.
- Drawing setThe same set the estimate was priced from, including architectural, structural, MEP, and civil sheets. A later revision changes the audit baseline.
- Spec sectionsAt minimum Divisions 03, 05, 09, 22, 23, 26, and 31. Board thickness, pressure class, and insulation thickness live here, not on the plans.
- Project locationZIP code for material and labor pricing. State and county help us apply the right sales tax and prevailing-wage assumptions.
- Bid date or GMP deadlineSo we can sequence the audit and flag which variances need a decision before you submit or sign.
- Known concernsTell us which line items you already doubt. We will prioritize those divisions and show the measurement behind each one.
Sample audit variance schedule
This is the format we return. Each row shows the original estimate quantity, our re-measured quantity, and the variance, tied to the drawing sheet it was measured from.
| Section | Line item | Qty | Unit | Ref. |
|---|---|---|---|---|
| 033000 | Cast-in-place concrete, 4000 psi, slab-on-grade | 395.1 | CY | S-101 |
| 031000 | Formwork contact area, foundation walls | 6,080 | SF | S-201 |
| 051200 | Structural steel, W-shapes and connection material | 142.5 | TON | S-301 |
| 092900 | Gypsum board, 5/8" Type X, Level 4 finish | 48,200 | SF | A-401 |
| 233113 | Ductwork, galvanized, 2" w.g. pressure class | 18,400 | LB | M-501 |
| 221116 | Domestic water piping, Type L copper | 3,250 | LF | P-601 |
| 260519 | Wire and conduit, EMT and THHN | 12,800 | LF | E-701 |
| 312000 | Earthwork, cut and fill with shrink factor | 8,450 | CY | C-101 |
| 055000 | Miscellaneous metals, lintels and embed plates | 4,200 | LB | S-401 |
| 230700 | HVAC duct insulation, 1-1/2" thick, foil-faced | 9,600 | SF | M-502 |
| 220500 | Pipe hangers and seismic bracing | 1,150 | EA | P-602 |
| 260526 | Grounding and bonding, main ground bar and conductors | 1 | LS | E-702 |
Units of measure used in the quantity takeoff audit
Quantities are reported in the unit that matches how the work is bought and installed. The table shows the units we use most often and how each is measured from the drawings.
| Item | Unit | How it's measured |
|---|---|---|
| Concrete, earthwork, fill | CY | Volume from plan dimensions, with waste and shrink/swell applied separately |
| Formwork contact area, drywall, roofing, flooring | SF | Surface area measured from plan and section, excluding openings per spec |
| Pipe, conduit, base, edge forms, joint sealant | LF | Centerline length from plan, including vertical drops and offsets |
| Structural steel, rebar, HVAC equipment | TON | Calculated weight from member sizes and schedules, plus connection material |
| Fixtures, devices, doors, fittings | EA | Count from schedules, plans, and details, with spare and spare-parts noted |
| Rough carpentry lumber | MBF or BF | Board feet from framing plans and cut lists, with waste factor |
| Roofing | SQ | Roof plan area divided by 100, with waste and flashing measured separately |
| Allowances, permits, mobilization | LS | Lump sum carried as a separate audited line, not buried in unit rates |
Worked example: auditing a concrete slab-on-grade line
This example shows how we re-measure a single line item from the reviewed estimate. The dimensions are illustrative and do not represent a real project.
Given: The estimate shows 395.1 CY of 4000 psi concrete for slab-on-grade. The slab is shown on sheet S-101 as 4 inches thick over a 32,000 SF building footprint. The spec section 033000 requires a 5% waste factor and a vapor barrier under the slab.
Step 1: Verify the slab area from the drawing.
- Building footprint: 200 ft × 160 ft = 32,000 SF.
- Deduct openings: two equipment pads, each 10 ft × 10 ft = 200 SF total.
- Net slab area = 32,000 SF − 200 SF = 31,800 SF.
Step 2: Convert thickness to feet and calculate volume.
- Thickness = 4 in ÷ 12 in/ft = 0.333 ft.
- Volume = 31,800 SF × 0.333 ft = 10,589.4 CF.
- Convert to cubic yards: 10,589.4 CF ÷ 27 CF/CY = 392.2 CY.
Step 3: Apply waste factor as a separate line.
- Waste = 5% of 392.2 CY = 19.6 CY.
- Total concrete = 392.2 CY + 19.6 CY = 411.8 CY.
Step 4: Compare to the estimate.
- Estimate quantity: 395.1 CY.
- Re-measured quantity: 411.8 CY.
- Variance: 16.7 CY short (4.2% under).
Step 5: Check the unit rate.
- The estimate uses $145 per CY for 4000 psi concrete, placed.
- Our ZIP-code-adjusted rate for the project location is $152 per CY.
- Rate variance: $7 per CY low.
Step 6: Calculate dollar impact.
- Quantity impact: 16.7 CY × $152/CY = $2,538.
- Rate impact: 395.1 CY × $7/CY = $2,766.
- Total variance on this line: $5,304.
Step 7: Flag related scope gaps.
- Vapor barrier: 31,800 SF. Not shown in the estimate. At $0.35/SF, add $11,130.
- Formwork edge forms: 720 LF (perimeter). Not shown. At $4.50/LF, add $3,240.
- Dowels at construction joints: 120 EA. Not shown. At $8.50/EA, add $1,020.
Step 8: Document and mark up.
- Mark the slab area on S-101 with the net SF and the deduction for equipment pads.
- Note the spec section 033000 requirement for the 5% waste factor.
- Attach the unit-rate basis from RSMeans data adjusted for the ZIP code.
Audit result for this line: The estimate is short $5,304 on concrete quantity and rate, plus $15,390 in related scope gaps, for a total variance of $20,694 on the slab-on-grade alone. This variance is ranked in the PDF summary by dollar impact.
What moves the audited construction cost estimate review
Relative impact on a typical estimate for this trade, based on estimator judgment. Select a bar for details.
Formwork vs. concrete
Formwork is measured as contact area in SF, not as concrete volume. When an estimate prices formwork as a percentage of concrete CY, wall-heavy projects come in low and slab-heavy projects come in high. We separate the two and re-measure contact area from the wall sections and footing details.
Formwork is measured as contact area in SF, not as concrete volume. When an estimate prices formwork as a percentage of concrete CY, wall-heavy projects come in low and slab-heavy projects come in high. We separate the two and re-measure contact area from the wall sections and footing details.
Net calculated rebar weight excludes lap splices, chairs, and waste. Typical waste factors run 5 to 10 percent depending on bar size and placing method. If the estimate uses net weight, the TON count is short, and the error compounds through the concrete division.
Gypsum board priced at Level 4 but specified as Level 5 changes the labor rate per SF, not the board count. We read the finish level from the architectural spec and the reflected ceiling plans, then reprice the affected SF. This is one of the most common single-line variances in interior scopes.
Duct gauge is set by pressure class, not by duct size alone. A 2-inch w.g. system uses lighter gauge than a 4-inch w.g. system at the same dimensions. When the estimate takes gauge from the size only, the LB count and the sheet-metal labor both drift.
Counting conduit and wire from the panel schedule gives the feeder and branch circuit counts but not the home-run lengths. We scale the runs from the panel to the device on the plan, add vertical drops, and compare the LF against the estimate. Missing home runs is a frequent electrical variance.
Cut and fill volumes are not interchangeable. Bank cubic yards shrink when excavated and swell when placed as fill. If the estimate treats them as equal, the earthwork balance and the import or export CY are both wrong. We apply the factors stated in the geotechnical report.
Material pricing often excludes sales tax, freight, and delivery. These costs are added at the quote stage but may be omitted from the estimate. We check the pricing basis and flag any material line that does not include them, using the project ZIP code to apply the correct tax rate.
Material and labor rates change between the estimate date and the bid date. If the estimate was priced months earlier, the rates may be stale. We flag the date gap and identify divisions most exposed to escalation, such as structural steel and electrical equipment.
Scope gaps we find most often in a subcontractor estimate review
These are the omissions that survive a normal review because they hide between divisions or between the plans and the spec. We catch them by measuring the drawings against the estimate line by line.
- Pipe hangers, seismic bracing, and insulation are left out of the mechanical scope. They appear in the spec section and on the riser details, not in the plan piping count. We add them as separate audited lines by size and spacing.
- Roof insulation thickness is taken from the spec section instead of the roof plan detail. The detail often shows a tapered or two-layer system. We measure from the detail and flag the difference in SF and thickness.
- Door hardware sets are priced as a lump sum instead of per-set from the hardware schedule. The schedule lists each set by type and function. We count the sets and compare the per-set rate.
- Sales tax, freight, and delivery are not included in material pricing. These show up in the quote, not the estimate. We check the pricing basis and flag any material line that omits them.
- Escalation to the bid date is not applied to material and labor rates. If the estimate was priced months before the bid, the rates are stale. We flag the date gap and the divisions most exposed to escalation.
- General conditions duration is shorter than the schedule shows. We compare the GC line to the project schedule and flag the month and staffing difference as a separate audited line.
- Firestopping at rated wall and floor penetrations is missing from the estimate. The locations are shown on the life safety plans and in the UL details. We count the penetrations by type and size and add them as a line item.
- Roof drainage, including primary and overflow scuppers, conductors, and splash blocks, is not priced. These appear on the roof plan and plumbing details. We measure the linear feet of conductor and count the scuppers and add them to the audit.
- Concrete reinforcement accessories such as chairs, bolsters, and dowels are omitted. They are specified in Division 03 and shown on structural details. We calculate the quantity per SF of slab or LF of wall and flag the missing TON or EA.
- Mechanical equipment vibration isolation and seismic restraints are not included. The spec section requires them, but they are not on the plan. We add them as a separate line based on equipment weights and locations.
- Electrical conduit and wire for fire alarm and low-voltage systems are left out when the estimate only covers power. These systems are shown on the separate fire alarm and telecom plans. We measure the conduit and count the devices and flag the gap.
- Temporary heating, cooling, and ventilation during construction are not priced in general conditions. The spec may require them for certain finishes. We flag the omission and note the duration from the schedule.
Material cost unit-rate comparison for key materials
We compare the unit rates in your estimate to ZIP-code-adjusted rates for the project location. The table shows the materials we check most often and the unit of measure we use.
| Material | Unit | What we check | Common variance driver |
|---|---|---|---|
| Concrete, 4000 psi | CY | Mix design price, placement method, and waste factor | Waste factor omitted or placed as a percentage of volume |
| Structural steel, W-shapes | TON | Mill price, fabrication, and connection material | Connection material and deck not included in tonnage |
| Gypsum board, 5/8" Type X | SF | Board price, level of finish, and waste | Level 5 finish priced at Level 4 labor rate |
| Ductwork, galvanized | LB | Gauge, pressure class, and sheet metal labor | Gauge taken from size only, not pressure class |
| Domestic water piping, Type L copper | LF | Material price, fittings, hangers, and insulation | Hangers, seismic bracing, and insulation omitted |
| Roofing membrane, TPO | SQ | Membrane, insulation thickness, and flashing | Insulation thickness from spec, not roof plan detail |
| Rebar, Grade 60 | TON | Bar size, lap, waste, and accessories | Lap and waste not added to net weight |
| Electrical conduit, EMT | LF | Raceway type, conductor size, and home runs | Home-run lengths not measured from panel to device |
Codes and standards that affect the audit
Model codes
Model codes set the minimum requirements that change quantities. The International Building Code (IBC) and International Residential Code (IRC) govern structural, fire, and life safety provisions. The International Energy Conservation Code (IECC) sets insulation and envelope requirements that change wall and roof assembly thickness. The National Electrical Code (NEC) dictates conduit fill, wire sizing, and grounding, which affect LF and EA counts. The International Plumbing Code (IPC) and Uniform Plumbing Code (UPC) set pipe sizing and fixture counts. NFPA 13 governs sprinkler head spacing and piping. Confirm the adopted code edition with the local building department, as editions vary by state and jurisdiction.
Industry standards
Industry standards define how materials are measured and installed. ACI 318 and ACI 301 govern concrete strength, reinforcement, and placement, affecting CY and TON. ASTM standards cover material specifications, such as ASTM A992 for structural steel and ASTM C840 for gypsum board application. SMACNA standards set duct construction and pressure classes, which determine gauge and LB. GA-214 defines gypsum board levels of finish, directly impacting labor rates per SF. NRCA guidelines cover roofing installation and flashing details, affecting SQ and LF.
Specification sections
Specification sections are where the cost-driving details live. Division 03 sections 033000 and 031000 specify concrete mix designs, waste factors, and formwork contact area. Division 05 sections 051200 and 052100 define steel tonnage, connections, and joist counts. Division 09 sections 092900 and 093000 set board thickness, finish level, and tile sizes. Division 22 section 221116 specifies pipe material, hangers, and insulation. Division 23 section 233113 sets duct gauge and pressure class. Division 26 section 260519 defines conduit and wire types. Division 31 section 312000 covers earthwork and shrink/swell factors. An estimator must read these sections to price correctly.
Local amendments
Local amendments modify model codes and change quantities. Some jurisdictions require stricter energy codes, adding insulation thickness and cost. Others have seismic requirements that increase bracing and anchorage for MEP systems. Fire codes may mandate additional firestopping or sprinkler coverage. Sales tax rates and prevailing wage laws also vary by location, affecting material and labor pricing. Always confirm the adopted code edition and local amendments with the local building department before finalizing an estimate. We apply ZIP-code-adjusted pricing but rely on you to provide the correct jurisdiction for code compliance.
Who uses this outsourced estimate review
General contractors
You are carrying a subcontractor's number into a hard bid or a GMP and need to know whether the quantities hold. The audit gives you a variance schedule you can take to the subcontractor or use to adjust your contingency before you sign.
Owners and developers
You have a budget from your team or a CM and need an independent read before you approve it. The audit shows which line items drive the total and where the estimate is thin, so your approval is based on measurement rather than confidence.
Subcontractors
You are pricing a scope from a GC's drawings and want a second set of eyes on your own takeoff before you submit. The audit confirms your quantities and flags any spec requirement you may have missed, such as a finish level or pressure class.
Architects and engineers
You are reviewing a contractor's estimate against your documents and need to see whether the scope you designed is fully priced. The marked-up set shows where quantities were measured and which details were not carried into the number.