Services Projects Areas Resources Company Get a Quote
Services

Construction Cost Estimating

Class D, C, B and A estimates and quantity surveys for Ontario projects, priced against the whole scope by a contractor that has to build to its numbers.

Know the Number

An estimate for every
stage of design

Construction cost estimating puts a defensible number on a project at each stage of design. Terrahills produces Class D estimates from concept information, Class C estimates from schematic design, Class B estimates from developed design and Class A estimates from complete documents, so the range narrows as the decisions get made.

Every estimate is built against the complete scope: land, approvals, servicing, site work, foundation, building, fire protection, fit-out and contingency. That is the difference between a building quotation and a project budget. Our preconstruction work on a 26,500 sq ft industrial building in Vaughan included cost planning through to a construction-ready package.

01
Class D estimates
  • From a concept, a program and a building type
  • Tests feasibility and compares options
  • Free and no obligation on Ontario projects
02
Class C estimates
  • From schematic plans, elevations and sections
  • Major elements measured and priced
  • Supports the investment decision
03
Class B estimates
  • From developed design
  • Structure, envelope and building systems defined
  • Confirms the project still works before full documentation
04
Class A estimates
  • From complete documents
  • Measured against the full drawings and specifications
  • Forms the basis of a fixed price
05
Quantity surveys & site costs
  • Materials and work measured from the drawings
  • Scope gaps found before tender
  • Grading, stormwater, servicing and foundations priced to the site
06
Budget control into construction
  • The estimate becomes the working budget
  • Changes visible before they happen
  • Project accounting and reporting through to occupancy

The full service list

Estimate Classes

Class D, C, B and A compared

Construction cost estimate classes and indicative accuracy
ClassPrepared fromTypical accuracyUsed to
Class DConcept site plan, program and building typeUp to ±30%Test feasibility, set the first budget and compare options
Class CSchematic plans, elevations, sections and preliminary materials±15% to ±20%Choose the scheme and make the investment decision
Class BDeveloped design, with the structure, envelope and mechanical systems defined±10% to ±15%Confirm the project still works before committing to full documentation
Class AComplete drawings and specifications±5% to ±10%Establish the basis of a fixed price

The range narrows at each class because more of the project has been decided. Accuracy figures are Canadian Institute of Quantity Surveyors guidance for expected variance from the contract award price, excluding unusual projects. The assumptions and exclusions matter as much as the total, so read them first.

Published Cost Guidance

Start with a benchmark,
then price your site

Per-square-foot ranges are useful for a first conversation and unreliable for a decision. These guides explain what drives the number in each sector and what sits outside it.

FAQ

Questions owners ask us

Plain answers about construction cost estimating from an Ontario general contractor.

The difference is how much of the project has been designed. A Class D estimate works from concept information and is used to test feasibility. A Class C estimate works from schematic design and supports the investment decision. A Class B estimate works from developed design and confirms the project still works. A Class A estimate is prepared from complete documents and forms the basis of a fixed price.
Canadian Institute of Quantity Surveyors guidance puts a Class D estimate within about 30% of the contract award price, the widest range of the four, because the design is still at concept. It is accurate enough to decide whether to continue and to compare options. It is not a price. The range narrows to about 15 to 20% at Class C, 10 to 15% at Class B and 5 to 10% at Class A.
The complete project scope: approvals, servicing, site work, foundation, building, fire protection, fit-out and contingency, with land and development charges carried in the project budget. An estimate that covers only the building leaves out the items most likely to cause an overrun.
No. A steel building quotation prices the supplier's package. A construction estimate prices the whole project around it, including site work, foundations, fire protection, fit-out and contingency, which together can far exceed the cost of the steel.
A quantity survey measures the materials and work shown on the drawings so that cost can be built up from actual quantities. It gives an estimate a measured basis, exposes gaps in the scope and allows trade prices to be compared on the same footing.
Yes. Terrahills provides a free, no-obligation Class D estimate on Ontario construction projects. Class C, Class B and Class A estimates follow as the design develops and are scoped with the project.
Send the drawings and specifications and tell us what decision the number has to support. The class of estimate depends on how complete the documents are, and we will confirm how we can help once we have reviewed them.
Industrial, cold storage, self storage, data centre, healthcare, multi-residential, infrastructure, custom home and commercial projects anywhere in Ontario.
Get a number you can plan on

Start Your Project Today

Tell us the site and the program. We will come back with a free, no-obligation Class D estimate against the whole scope, anywhere in Ontario.

Request a Free Concept Estimate →