Nine chapters on how construction and infrastructure estimates are actually built in Australia — what goes into them, what accuracy you are entitled to claim, and what it costs when the method is wrong. Free to read, no sign-up.
A tool cannot be neutral about the work it performs. The moment a program decides that a rate is a number you type, rather than a result you assemble, it has taken a position on what estimating is — and every estimator using it inherits that position, usually without being told.
That is the argument this guide makes. First-principles estimating — pricing an item from the crew, plant, materials and production rate that will actually deliver it — is not a software feature. It is a discipline with its own literature, its own failure modes and a few decades of uncomfortable evidence about how badly projects estimate when the discipline is skipped. Software either supports that discipline or quietly erodes it.
So the nine chapters below are about the method, not the product. They explain how the work is done, where it goes wrong, and what the wrong answer costs. Where TX1:Trinity does something relevant, each chapter says so at the end — after the method, not instead of it.
TX1:Trinity is the Windows desktop application these chapters describe in practice. The trial runs 14 days, takes no credit card, and is the full program rather than a demonstration.
Start a free 14-day trialRead them in order if the subject is new to you; chapters 01 and 02 set the vocabulary the rest depend on. Otherwise go straight to whichever problem is currently on your desk.
The single thing to take from this guide: an estimate is only as defensible as the build-up underneath it, so the question worth asking of any number is not "is it right?" but "can you show me what it is made of?"
Each page defines its terms, shows the mechanism, gives you a table or a worked structure you can argue with, names the mistakes that are common enough to be predictable, and ends with the single sentence worth remembering. Nothing is gated and nothing asks for an email address.
The technique is explained so it can be carried out by hand. Where the software changes the work, that is the last section, clearly marked.
Standards, methods of measurement and contract forms as they are used here, with clause-level references rather than gestures at "industry best practice".
Authored by a practising principal cost engineer (RPEQ #22276, CPEng #4275634), from estimates that were actually submitted and actually audited.
The number at the bottom of a tender is the least interesting thing about an estimate. What matters is whether anyone — a reviewer, a probity auditor, a client's cost consultant, or you in eighteen months when the claim lands — can open the item and see the crew, the production rate, the wastage and the assumptions that produced it.
That is the test every chapter here is written against. It is also the test that separates an estimate from a guess with a decimal point on it, and it is the reason a first-principles build-up survives scrutiny that a benchmarked lump sum does not.
TX1:Trinity is a Windows desktop estimating platform built on exactly the position this guide argues. Items are priced from coded labour, plant, material and subcontract resources; built-up resources recompute as the sum of their contributing rows, so a component change cascades to the package rate, to every item using it, and to all allocations. A parametric formula engine keeps the arithmetic and its assumptions inside the estimate. Embodied carbon is tracked on the same objects as cost rather than in a parallel model.
None of that is required to use this guide. All of it exists because the guide's argument had to be made to work at scale — our own Transport and Main Roads library runs to 1,852 priced items.
No. The nine chapters describe how first-principles estimating works as a discipline, and every technique in them can be carried out by hand or in a spreadsheet. The chapters note where TX1:Trinity does a particular job differently, but the method comes first and the software is the last section of each page.
Read chapter 01, First principles, then chapter 02, Estimate anatomy. Together they set the vocabulary the rest of the guide uses. After that the chapters are independent, so go to whichever problem is in front of you.
It is written from Australian practice and refers to the standards, methods of measurement and contract forms used here. The underlying method is not jurisdiction-specific, but the worked references are.
This cluster is about estimating as a discipline. The user guide is the software documentation — every screen, every formula, every workflow, with exact click paths. Read this one to decide what to do; read that one to find out where the button is.
If you would rather see the method implemented than read about it, these are the two places to go next.
Install TX1:Trinity and price one item you already know the answer to. Fourteen days, no credit card, the full desktop application.