A product-level environmental figure is easy to repeat because it looks like a compact answer. One material is associated with a lower number per kilogram than another. The apparent ranking is clear, and the temptation is to describe the first as the better proposal. In construction, that conclusion can arrive before anyone has established how much of each material the project requires or whether the alternatives provide an equivalent function.
I think technology leaders should insist on that functional question before the comparison acquires a public narrative. The intention is not to make environmental analysis so difficult that no decision can be taken. It is to stop a convenient unit from answering the wrong question. The project needs an assembly or structure with a particular performance, not an isolated kilogram purchased without a purpose. Quantity and suitability connect the product information with the proposed building.
This becomes a leadership issue when different teams own different parts of the explanation. A materials specialist may understand the product data. The structural team determines whether an option meets the brief. Procurement knows the available sources and delivery constraints. Commercial colleagues may already be considering what can be said to a client. Unless those accounts meet, a technically correct statement about a product can become a misleading statement about the proposed works.
Agree what the alternatives must provide
In a July 2025 concept comparison at Varelim, we examined two steel options against a common functional brief. Structural specialists confirmed the basis for comparing the concepts, while detailed design checks remained outstanding. That was a useful stage for investigation: there was enough definition to compare quantities, but sufficient design work remained that neither option should be described as a completed solution.
An environmental reviewer examined the product-category rules, system boundary and data basis behind the factors used. Those checks mattered because similar-looking figures do not necessarily describe the same processes or assumptions. A number with more decimal places is not automatically more comparable. The reviewer needed to understand what each declaration covered and whether it could support the particular comparison we were making. My role was to make that work part of the decision timetable.
The shared functional brief did not mean that all commercial differences disappeared. Supply routes, fabrication arrangements, connections and programme implications still needed attention. It meant that the initial comparison was tied to a stated purpose rather than treated as a contest between detached product labels. We could then explain what had been held consistent and what remained open, which is more useful than presenting a ranking without its construction context.
The nine-week study cost S$510,000. That cost included the work needed to make the alternatives intelligible as proposals. It would have been cheaper to compare two headline factors and produce a slide. It would also have left the main question unanswered. A meaningful comparison sometimes requires paying for evidence that reveals why the obvious ranking is incomplete.
Multiply before telling the story
The concept quantities were eighty kilograms of steel per square metre of supported floor for option A and sixty for option B. The production-stage factors used were 2.1 kilograms of carbon-dioxide equivalent per kilogram of steel for A and 2.6 for B. On the product factor alone, A looked lower. Applying the quantities produced 168 and 156 kilograms of carbon-dioxide equivalent per square metre respectively. The arithmetic changed the order for that defined comparison.
It did not establish the whole environmental performance of either building. The calculation excluded transport, erection, use and end of life. It did not demonstrate a realised reduction on a completed project. Nor did it remove the detailed design checks that still stood between a concept and a selected system. The proper statement was narrower: under the study's common basis, the production-stage estimate for the specified quantity was lower for B.
That narrower statement was still valuable. It prevented the lower per-kilogram figure from ending the discussion prematurely and justified keeping both options in commercial review. Environmental analysis does not have to deliver a complete answer to improve a decision. It can expose a mistaken shortcut, clarify the remaining questions and help the team direct its next work. The benefit is lost when the limited finding is either exaggerated or dismissed as useless because it is not comprehensive.
I also wanted the units to remain visible wherever the result appeared. A table can be copied without its introductory paragraph, and a chart can travel into a different presentation. Stating the quantity basis and the production-stage boundary beside the values reduces the chance that a later reader will interpret them as lifetime building emissions. The point is not to attach an unreadable qualification to every sentence. It is to retain context that changes what the numbers mean.
Let the comparison inform a wider choice
Our decision was to continue assessing both options. Cost, supply confidence and fabrication consequences remained relevant. We did not select B solely because its concept-stage production estimate was lower. A construction proposal has to satisfy its technical brief and be deliverable under the project's actual conditions. Treating environmental evidence seriously means bringing it into that decision, not pretending the other dimensions have ceased to exist.
This can produce disagreement without anyone being indifferent to environmental performance. Procurement may question whether the assumed source is available in the required period. Engineering may identify a detail that changes quantity. The client may value a different delivery arrangement. Each objection should be examined for its effect on the comparison rather than categorised immediately as resistance. Some will change the preferred option; others will show that an assumption needs better support.
I would improve our process by agreeing the functional basis earlier, before colleagues invest too much effort in a preferred material story. That would allow the environmental reviewer and structural specialists to shape the initial information request together. It would also make the unresolved design work clearer to the commercial team. A comparison becomes easier to communicate when its purpose is settled before the numbers arrive.
The board-level question is therefore not simply whether the company uses lower-impact materials. It is how the company establishes the environmental meaning of its actual proposals and keeps that meaning intact as choices change. The evidence may begin with a product declaration, but the business is accountable for the claim it makes about a project. Leaders should understand how quantity, function and boundary connect those two levels.
The example does not offer a preferred steel factor or a general material recommendation. Its lesson is a method of questioning. Ask what the alternative must do, establish the quantity on a defensible basis and retain the scope of the environmental calculation. Then bring the result into the wider choice. That sequence creates room for a more informed decision, including the possibility that the initially attractive product label does not describe the more attractive construction proposal.