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Estimate type · Concept to design development

Budget and conceptual estimates

A budget or conceptual estimate is an early cost summary built from incomplete design.

Request a budget estimateWhat you get
Typical estimate accuracy ranges narrow as design developsAACE 56R-08 classes for building construction, by end use. Class 5 concept screening: low minus 20 to 30 percent, high plus 30 to 50 percent. Class 4: minus 10 to 20, plus 20 to 30. Class 3: minus 5 to 15, plus 10 to 20. Class 2: minus 5 to 10, plus 5 to 15. Class 1: minus 3 to 5, plus 3 to 10.Design developsHighLow+30 to +50%−20 to −30%Class 5Conceptscreening+20 to +30%−10 to −20%Class 4Schematic orconcept study+10 to +20%−5 to −15%Class 3Budgetauthorization+5 to +15%−5 to −10%Class 2Control orbid/tender+3 to +10%−3 to −5%Class 1Check, bid orchange orderTypical estimate accuracy ranges narrow as design developsAACE 56R-08 classes for building construction, by end use. Class 5 concept screening: low minus 20 to 30 percent, high plus 30 to 50 percent. Class 4: minus 10 to 20, plus 20 to 30. Class 3: minus 5 to 15, plus 10 to 20. Class 2: minus 5 to 10, plus 5 to 15. Class 1: minus 3 to 5, plus 3 to 10.Class 5Conceptscreening+30 to +50%−20 to −30%Class 4Schematic orconcept study+20 to +30%−10 to −20%Class 3Budgetauthorization+10 to +20%−5 to −15%Class 2Control orbid/tender+5 to +15%−5 to −10%Class 1Check, bid orchange order+3 to +10%−3 to −5%

Typical ranges from AACE International Recommended Practice 56R-08 for building and general construction, at an 80% confidence interval after contingency.

Estimate ranges, narrowing as design develops.

The service

What you send. What you get.

You send

  1. Concept, schematic or design development plans
  2. Program or outline specification, if available
  3. Site information and any geotechnical findings
  4. Historical costs or rates you approve
  5. Target budget or design options to compare

Start with a short description. We arrange document sharing after confirming the work.

You get

  1. Budget summaryCost by system or division, with the pricing basis named for each line.
  2. Assumptions registerWhat the design does not show yet and what the number assumes in its place.
  3. Option comparisonSide-by-side costs for design options you ask us to test.
  4. Classification noteThe design stage and AACE estimate class the number reflects, so readers know what it can support.

Typical buyers: General contractors and construction managers pricing early design; Design-build teams setting a target cost; Preconstruction managers testing design options.

What goes in

Built from your documents.

The estimate is priced with square foot, parametric or assembly methods and cost data you approve. It names the pricing basis for each line, the assumptions standing in for missing design and the design stage it reflects. Expected accuracy ranges narrow as design matures. We confirm fit and a fixed quote after reviewing your documents.

  • Cost by building system or MasterFormat division
  • Key parameters such as gross floor area (SF), units and stories
  • Pricing basis for each line: parametric, assembly or unit cost
  • Design stage and documents used
  • Allowances, escalation and contingency as you set them
  • Assumptions for design not yet shown

Before we start

Questions to resolve and work not included.

Questions we help identify

  • Structural system not yet selected
  • Mechanical and electrical systems described only in narrative form
  • Site and utility scope not defined
  • Finish quality level not stated

Not included

  • Design, engineering and value engineering decisions
  • Escalation and market forecasts beyond the factors you approve
  • Firm pricing commitments: a budget is not a bid
  • Site visits and field verification

Questions

About budget and conceptual estimates.

How accurate is a budget estimate?

It depends on how complete the design is. AACE International RP 56R-08 gives typical ranges for building projects of -20% to -30% on the low side and +30% to +50% on the high side at the earliest class, narrowing as design matures. These are industry reference ranges, not a promise about any single estimate.

What do the AACE estimate classes mean?

AACE sorts estimates into five classes by how mature the project definition is, from Class 5 for concept screening to Class 1 for check estimates, bids and change orders. The class tells readers what the number can support.

What do I need to provide?

The current design documents, any program or outline specification, site information and the cost data or rates you want used. You approve the assumptions, contingency and escalation before the number is used.

Related

Sources

Where the rules come from.

Send the plan set details.

We confirm availability, scope, price and timing before any work begins.

Request a budget estimateHow it works