What goes into a construction cost estimate
A construction cost estimate is the dollar-denominated version of a takeoff. Where the takeoff says “1,840 cubic yards of 4000 psi concrete,” the estimate says “1,840 CY × $182/CY in-place = $334,880 for concrete.” The estimate adds labor productivity, crew composition, equipment costs, subcontract markups, jobsite overhead, home-office overhead, profit, and risk allowances on top of the raw quantity work.
A Vortex cost estimate covers six layers:
1. Direct material cost
Quantities from the takeoff, priced with current material costs. We use RSMeans for the baseline, regional supplier quotes for any item where market volatility makes the RSMeans figure stale (lumber, steel, copper, concrete), and your own pricebook if you have one.
2. Direct labor cost
Productivity figures (man-hours per unit) from RSMeans crew tables, NECA Manual of Labor Units for electrical, or MCAA Labor Estimating Manual for mechanical, multiplied by local labor rates. Rates default to open-shop unless your project triggers prevailing-wage or Davis-Bacon, in which case we apply the appropriate classification rate.
3. Direct equipment cost
Rental, fuel, operator, and mobilization. Equipment that runs less than 50% of project duration is typically priced at monthly rental; equipment running continuously is priced at the lower of weekly rental or owned-cost equivalent.
4. Subcontract markup
For trades being subbed out, we either build a parallel cost-up using the same bottom-up method (treating the sub’s price as if we were doing the work), or coordinate solicitation of sub quotes against the takeoff package.
5. Indirect cost
General conditions (jobsite supervision, trailer, temp utilities, dumpsters, security), home-office overhead allocation, bonds, general liability and builder’s risk insurance, builder’s risk deductible reserve, and warranty reserve.
6. Contingency and profit
Contingency at the appropriate AACE Class percentage. Profit at the contractor’s standard markup (we leave the profit percentage as an editable input — that’s your business decision).
AACE Estimate Classes in detail
The AACE estimate-class system is the de-facto standard for cost-estimate quality in the United States. Each class corresponds to a stage of design maturity and an expected accuracy range.
Class 5 — Concept Screening
Design maturity: 0-2%. The project may be just a sketch or a written program. Method: Analogous (comparison to past projects) or parametric (cost per square foot from a database). Accuracy: -50% to +100% of true cost. Use case: Feasibility, go/no-go decisions, internal screening of investment options. Typical turnaround: 24-48 hours.
Class 4 — Study or Feasibility
Design maturity: 1-15%. Schematic-stage drawings, programmed gross areas. Method: Parametric with cost-per-unit-area or unit-of-capacity figures, supplemented by major-equipment lists where industrial. Accuracy: -30% to +50%. Use case: Project authorization, business case development. Typical turnaround: 3-5 days.
Class 3 — Budget, Authorization, Control
Design maturity: 10-40%. Design development complete, equipment lists firming up. Method: Semi-detailed unit costs applied to assemblies; major bulk quantities measured. Accuracy: -20% to +30%. Use case: Project budget setting, capital cost approval, design control budget. Typical turnaround: 5-10 days.
Class 2 — Control or Bid/Tender
Design maturity: 30-70%. Construction documents largely complete. Method: Forced-detail unit-rate estimate. Quantities from full takeoff against working drawings. Accuracy: -15% to +20%. Use case: Cost control during construction, fixed-budget validation, design-build target pricing. Typical turnaround: 7-12 days.
Class 1 — Bid or Tender
Design maturity: 65-100%. Construction documents complete and issued for bid. Method: Full bottom-up estimate. Every quantity counted, every labor productivity reviewed. Accuracy: -10% to +15%. Use case: Hard bid submission, GMP negotiation, claim defense. Typical turnaround: 10-20 days for full commercial projects; faster for narrow scope.
When parametric beats bottom-up
Bottom-up estimating is the gold standard, but it is not always the right tool. For an early-stage feasibility analysis where the design is a written program with no drawings, a parametric estimate will get you within ±30% in two days; a bottom-up estimate is impossible because there is nothing to take off.
A few examples where parametric is the right choice:
- A real estate developer pricing a 200-unit apartment project against a market study, before architects are engaged
- An owner pressure-testing a contractor’s GMP at the schematic-design stage
- A property buyer estimating renovation cost from listing photos to make an offer
- An insurance adjuster pricing a building loss at the time of inspection
For everything past schematic design, bottom-up is faster, more defensible, and more useful.
What we use for pricing data
Current pricing is the difference between an estimate that ages well and one that is stale before it lands on your desk. We maintain active subscriptions to:
- RSMeans Construction Cost Data — the industry standard, updated quarterly, with 731 US city cost modifiers
- BNi Building News — regional pricebooks for the western, central, and eastern US
- Compass International — international and remote-area cost data
- R.S. Means Heavy Construction — civil and infrastructure pricing
- NAHB Cost of Doing Business Study — residential overhead and profit benchmarks
- NECA Manual of Labor Units — electrical labor productivity
- MCAA Labor Estimating Manual — mechanical and plumbing labor productivity
For volatile materials (lumber, structural steel, copper, concrete, fuel) we cross-check against current spot prices and regional supplier quotes before final estimate issue.