What Is a Class 3 Cost Estimate?

What is a Class 3 cost estimate?

A Class 3 cost estimate is a concept-stage construction cost estimate, ranked using the AACE International cost estimate classification system (Class 5 through Class 1, with Class 5 the roughest and Class 1 the most detailed). A Class 3 estimate sits in the middle of that scale: enough design information exists to price the project with reasonable confidence, but the drawings are not yet developed to construction-certificate (CC) level. In Australia, it's the estimate most developers, owner-builders and architects commission at feasibility or pre-DA stage, before a builder is engaged.

What accuracy does a Class 3 estimate carry?

Under the AACE classification system, a Class 3 estimate is prepared against roughly 10% to 40% project definition and typically carries an accuracy range of around -10% to -20% on the low side and +10% to +30% on the high side. That range reflects how much of the design is still unresolved, not the estimator's guesswork: the more the drawings still have to move, the wider the band has to be. As a design firms up towards CC issue, the same project graduates to a tighter Class 2 or Class 1 estimate.

When do you need a Class 3 estimate?

A Class 3 estimate earns its keep at three points in a project's life:

• Feasibility: working out whether a site stacks up before committing to detailed design.
• Pre-DA: testing a concept scheme against a budget before lodging with council.
• Before engaging a builder: having an independent number to sanity-check a builder's tender against, so a quote can't be accepted, or negotiated, blind.

If you already have full construction drawings and are ready to tender, a Class 3 estimate is the wrong product. At that stage you want a priced Bill of Quantities or a builder's fixed-price quote instead.

What does a Class 3 estimate contain, and how does it differ from a builder's quote?

A Class 3 estimate applies measured or benchmarked quantities and current market rates across the whole project: preliminaries, site works, services, the building structure and externals (see what's included in a full construction estimate), producing a total dollar figure with an element or trade breakdown. A builder's quote, by contrast, is a fixed-price offer tied to one builder's margin, program and subcontractor relationships, and it usually only exists once you already have a scheme worth tendering. HYKSOS prices Class 3 Budget Estimates for developers, owner-builders and architects from $2,500 to $25,000 ex GST depending on project scale and complexity.