Four knots in the system: WLC-GWP requires direction, not arithmetic

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Construction and Installation Hub
February 19, 2026
6 min

The aim of the EPBD is to steer towards better choices now, argues Jan Willem van de Groep in this issue of Zichtlijnen. A good determination method makes it possible to put a clear dot on the horizon. Those who lose sight of that will irrevocably find themselves in a multiple knot.

With the revised EPBD, Europe has made a clear choice. The climate impact of buildings is no longer limited to energy use in the use phase, but assessed over the entire life cycle. The introduction of WLC-GWP is thus not a technocratic exercise, but a steering tool. This is precisely where confusion now arises. About module D. About modular steering. About biogenic carbon storage. And now also about whether the instrument would be "too stringent" for the building sector.

This confusion hinders effective policy action.

The purpose of the EPBD is clear. To reduce cumulative greenhouse gas emissions toward 2050 through better design choices today. To this end, WLC-GWP is neither a climate bill nor an emissions register, but an ex ante design tool. It should help designers, developers and clients make better material and system choices. Anyone who loses sight of that premise is going to use WLC incorrectly and inevitably tangle with the systematics.

The first node: module D and the lure of the total score

The first node is at module D. In the normative system, module D is outside the life cycle. It deals with potential end-of-life impacts, depending on assumptions about reuse, recycling and energy recovery. These effects are uncertain and context-dependent. That is precisely why they are positioned as additional information and not part of the core score.

Yet the tendency to factor Module D into a single overall score pops up again and again. That seems appealing because it can make outcomes prettier, but it undermines exactly what WLC is supposed to do. It mixes certain emissions within the life cycle with speculative effects outside it. This removes transparency and trades steering for accounting optimization.

A comprehensive legal and methodological rationale shows that the EPBD, EN15978 and the Level(s) framework are mutually consistent in positioning module D outside the life cycle and thus outside a composite one-point score. This analysis is available via this link view.

The second node: modular steering is not an intermediate step

The second node concerns modular steering. The EPBD and the European policy framework explicitly opt for reporting by life-cycle stage. This is not a temporary solution, but a conscious design choice. The product phase, use phase and end-of-life phase have different knobs and different policy instruments.

By keeping those phases visible, policies can be tightened in a targeted way where it makes sense. In practice, however, we see that modular reporting is sometimes read as a weakness, as if only an all-encompassing total score would be mature policy. This is a misconception. It is precisely modular steering that prevents gains in one phase from masking structural damage in another. It enables phased standardization without losing sight of the end goal.

The third node: biogenic storage and the wrong time perspective

The third and most sensitive node concerns biogenic carbon storage. This is where two accounts get mixed up. In product standards, biogenic carbon is visible at the product stage and release only comes into the picture later. This leads to the reflex that biogenic storage is only temporary and therefore should not count in policy terms.

That reasoning ignores two crucial facts. First, homes don't stand for thirty or sixty years. In practice, they last toward a century or more. Thus, biogenic storage falls entirely within the critical period to 2050 when cumulative emissions are decisive. Second, the European goal of net zero by 2050 implies that uncompensated end-of-life emissions are no longer acceptable. The assumption that biogenic carbon will naturally re-enter the atmosphere does not fit with its own policy goal.

More importantly, here again two logics are mixed. WLC-GWP is not an emissions accounting system. It has no entitlements, no claims and no allocation. It controls, but does not charge. Thus, by definition, there can be no double counting. The function of WLC today is to enforce better material choices. Making biogenic storage visible in that context is not a claim to climate goals, but a way to avoid fossil emissions now and reduce cumulative emissions. That effect is real and relevant to meeting the goals of the EPBD.

The fourth node: standardizing gets confused with normalizing

Adding to this is a fourth knot that is increasingly surfacing in conversations with policymakers and market participants. The idea that including biogenic storage "tomorrow already" would lead to problems, because no one would be able to meet the standard by then. That idea rests on a fundamental misunderstanding.

What gets mixed up here is standardizing and normalizing.

Standardization is the careful shaping of a determination method. A method that is correct, future-proof and that makes it possible to steer towards the intended goal today and later. In this case, the structural reduction of the CO₂ footprint of buildings. The inclusion of biogenic storage in the determination method does not mean that from day one the maximum use of wood or other biobased materials will be standardized. It means that the method keeps that possibility open for the future.

Standardization is something else. It is the policy decision by the government to set a certain limit, at a certain time, at a certain rate. That standard may be deliberately below the theoretical possibilities of the determination method. That's exactly where the policy space is.

Usage is much broader than 'the norm'

What is often forgotten is that the legal method of determination is not only used by the government. Private parties also use this same methodology to go beyond the legal lower limit. Developers, investors and clients who want to raise the bar already need it. If the determination method does not provide that space, that ambition is made impossible, regardless of the standard the government uses in the Bbl.

A good determination method does more than just calculate. It makes it possible to set a clear dot on the horizon, linked to national emission targets, and makes visible where the policy is moving in the long run and which choices are structurally rewarded. Investments in plants, production lines, training and chains are not based on an ineffective standard, but on confidence that the chosen system is consistent and future-proof. When the determination method makes relevant effects visible, market participants can anticipate future tightening, even if the legal standard remains limited in the short term. If the method keeps those effects out of the picture, that investment signal is missing and it remains unclear which choices will actually be valued in the long run.

So the argument that "the industry can't handle it" focuses on the wrong button. It is not the method that is the problem, but the standard it can become. And the two need not coincide.

WLC as a steering tool, not a settlement mechanism

Confusion arises when WLC is treated as if it is part of formal EU climate accounting. It isn't. That accounting follows later, ex post, through other instruments. Those who confuse the two paralyze the design instrument for fear of notional risk.

The right choices for WLC-GWP are therefore obvious. Keep Module D out of the core score and use it only as supplementary information. Choose explicitly modular guidance and use that modularity to standardize in phases where the most impact is. Include biogenic storage in the determination method, without immediately making it normative, so that both public and private parties can steer for the future.

WLC-GWP doesn't have to capture everything. It needs to provide direction. If we continue to burden the tool with accounting anxieties and confusion between method and standard, we undermine the purpose of the EPBD. If we use it for its intended purpose, it will have exactly the impact Europe needs. Better buildings, better material choices and fewer emissions when it really matters.

This article was written by Jan Willem van de Groep, program maker, future thinker and publicist. Among other things, he is known for the government program Building Balance. In his column Sights, he gives his views on the big picture in construction.