ACA Architects’ Time/Cost Calculator – Version 4

13 May 2020 - Updated: 14 May 2024

The new and improved ACA Architects’ Time/Cost Calculator Guide (TCCG) helps businesses effectively manage their projects’ time and costs. The calculations derived from the TCCG provide a fundamental knowledge base for practices when developing fee proposals, based in the specifics of their practice. It assists practices of all sizes to assess the time and costs involved in providing an appropriate level of service for a wide range of building types, and accommodates a range of service levels and procurement types.

Log in to the Architects’ Time / Cost Calculator Version 4 


The Guide combines information supplied by users about their practice’s overheads, costs, expertise and project particulars with historic data about required hours to generate a suggested fee. It enables practices to tailor this information and knowledge to the particulars of their office.

The Guide is also a benchmarking tool, enabling practices to compare the office overheads of similar sized practices with their own. For example, are you paying much more on Professional Indemnity insurance than another practice of a similar size? The Guide can help you find that out, arming you with the information to help contain your overhead costs.

Version 4 introduces the flexibility for users to save an unlimited number of projects, each with its own overheads, hours and fees. This means you can track the details of each project, ensuring accurate cost estimation and budget management. The TCCG can also function as a simple calculator (without project information) for quick calculations if needed.

The TCCG also offers the opportunity to value Innovation and Commercial Risk within the Office Variables; a simplified login with one login screen; an updated interface that better supports mobile devices, such as tablets; and improved Safari support for our Apple users.

The Guide ensures that architects are better informed about the real time and costs associated with projects, and will, therefore be in a better position to negotiate fees that represent adequate time and resources to complete commissions to an appropriate standard. This is to the benefit of all.

The Architects’ Time/Cost Calculator is part of the ACA Business Toolbox, and is available to all members at no cost.

The Guide Process 

The Architects’ Time/Cost Calculator provides a four-step process:

  • Steps 1 and 2 allow practices to calculate their office overheads and office variables – this means that the cost calculations for each project are specific to the particulars of the individual practice. The data entered for Step 1 and 2 remain in place over time, and can be readily edited as practice circumstances change.
  • Step 3 identifies the estimated range of hours required for the project, based on multiple sets of historic data for different project types.
  • Step 4 identifies a charge-out rate for the project based on the information supplied about the practice and the project. Individual practices must then make their own adjustments in relation to project hours – based on specific knowledge of the expertise and experience within the practice. This enables the architect to determine a fee appropriate to their circumstances.

If you have queries about using the Guide, please contact us at

We hope you find the Guide useful.

Paul Viney led the development of the ACA Architects’ Time/Cost Calculator on behalf of the ACA VIC/TAS, and Jeff Beach of Big Dog Software built it. The ACA thanks Paul and Jeff for the enormous commitment they have made to this project, which is in its fourth version and has become a highly effective tool for architects across Australia.