World Green Building Council Introduces New Net Zero Carbon Buildings Commitment

The building industry can't ignore this anymore; upfront carbon emissions matter.

Net Zero in a Forest
Net Zero in a Forest.

iStock / Getty Images Plus

According to the World Green Building Council (WorldGBC), the construction sector is globally responsible for 35% of energy consumption, 38% of energy-related carbon emissions, and 50% of resource consumption. The WolrdGBC says a bold approach is needed to reduce this impact:

"This requires deep collaboration across the entire value chain, and radical transformation in the way buildings are designed, built, used, and deconstructed; new business models that promote circularity, re-use of buildings and materials, whole life cycle thinking, high performance operations, and ultimately a shift away from fossil fuels."

Over half of those emissions and almost all of that resource consumption happen before the doors of the building are open; they are the Embodied Carbon or as we prefer on Treehugger, the upfront carbon emissions, released during the mining, manufacturing, and construction of the building and its components. They have been studiously ignored by the industry and the regulators who since the 1970s were preoccupied with operating energy.

But we do not have an energy crisis now; we have a carbon crisis. We also have a carbon budget, the maximum amount of carbon dioxide (CO2) and equivalents, other greenhouse gases such as refrigerants, that can be added to the atmosphere. We have to cut emissions in half by 2030 and effectively to zero by 2050 if we are going to have even a hope of keeping the global rise in temperature to less than 2.7 degrees Fahrenheit (1.5 degrees Celsius).

This is why upfront carbon emissions matter so much now when every pound or kilogram of CO2e is coming out of the carbon budget. This is the time value of carbon, why the carbon that is emitted while making a building should be considered to be of primary importance.

targets for 2030


The WorldGBC has been a leader in promoting the importance of Upfront Carbon, and has introduced the Net Zero Carbon Buildings Commitment for 2030, for both new and existing buildings:

-Existing buildings reduce their energy consumption and eliminate emissions from energy and refrigerants removing fossil fuel use as fast as practicable (where applicable). Where necessary, compensate for residual emissions.
— New developments and major renovations are built to be highly efficient, powered by renewables, with a maximum reduction in embodied carbon and compensation of all residual upfront emissions.

The WorldGBC Commitment is that by 2030 "all new projects globally must achieve at least 40% embodied carbon reductions, with a focus on upfront carbon." Given the amount of time that it takes to change zoning bylaws, building codes, and client expectations, that really means that we have to start today.

To deal with operation carbon emissions, it calls for "reducing energy demand, shifting to renewable energy, and compensating for residual emissions from sources that cannot be abated (such as remaining fossil fuels or refrigerants). As quickly as practicable, buildings must shift to full use of renewables by removing equipment that uses fossil fuels."

A Whole Life Carbon Vision

Whole live vision


The WorldGBC has introduced what they call a Whole Life Carbon Vision with a framework for achieving "net zero operational and net zero embodied carbon buildings,"

"WorldGBC recognises that in most situations, net-zero energy buildings, i.e. buildings that generate 100% of their energy needs on-site, are not feasible and that net-zero embodied carbon should be pursued as part of a whole lifecycle approach to carbon reduction that includes net-zero operational carbon. Therefore a net-zero carbon vision that acknowledges the time value of carbon emissions from materials and construction, as well as recognising the role of offsets in facilitating the transition, is more appropriate for the mass scale required to achieve the urgent and significant carbon emission reductions necessary to align with IPCC guidance."

The inclusion of offsets is surprising and probably controversial. The WorldGBC recognizes it is not a long-term solution, seeing it as "a transition mechanism which compensates for current emissions, or as a tool for neutralising residual emissions which cannot be abated. They are not, however, an alternative to improving energy efficiency and transitioning to clean energy use within an entity’s own portfolio."



It is an interesting position; legitimate offsets can be expensive, so their inclusion can be a big incentive to avoid or reduce emissions in the first place. On the other hand, given the time value of carbon emissions, planting trees that take 60 years to absorb CO2 doesn't do much to offset a ton of emissions now.

To Deal With Embodied Carbon, We Have to Start At The Very Beginning

According to the commitment document,

"The Commitment now requires entities to consider the whole life carbon impacts of their actions; mandating that for all assets under direct control, achieve maximum operational and embodied carbon emission reductions, with all lifecycle stages considered, and compensate for any residual upfront emissions. The new embodied carbon requirements apply to all signatories who develop new building assets, or assets that undergo a significant renovation, within their direct control."

Note those words, "within their direct control." So much of this is actually beyond their control, because of zoning bylaws, parking requirements, and building codes, which should all be under examination right now, if authorities and regulators took the climate crisis and carbon emissions seriously, which they don't.

Here is a recent example of the problem:

One of the key approaches to reducing upfront carbon is to "reduce and optimize- to evaluate each design choice using a whole lifecycle carbon approach and seek to minimized upfront carbon impacts." Yet as architectural critic Alex Bozicovic demonstrates here, zoning bylaws can actually encourage complexity and inefficiency, by replacing the simple tower with a stepped form. If something like this is baked into the official plans and zoning bylaws now, it will be well after 2030 before it is changed.

Similarly, parking regulations can result in more concrete and embodied carbon being below grade; homes for cars can emit as much carbon as homes for people. You can't significantly reduce embodied carbon unless you reduce parking standards.

Zoning bylaws are often written to protect single-family housing, and then piling new higher density housing on to main streets. This makes our cities spiky, with inefficient concrete towers, instead of spreading the density around in lower buildings that can be built more easily with low-carbon materials like wood.

There is also "prevent- avoid embodied carbon from the outset by considering alternative strategies to deliver the desired function (e.g. renovation of existing buildings rather than new development etc.) " Treehugger has pointed out numerous times how this is ignored, particularly where it conflicts with the idea that we need to increase density.

Another important strategy is to "Plan for the future — take steps to avoid future embodied carbon during and at end of life (e.g. maximise potential for renovation, future adaptation, circularity etc.)" This is also rarely considered.

Is This Too Little, Too Late?

WGBC carbon
World Green Building Council

Ed Mazria, founder and CEO of Architecture 230 praises the report in the press release:

"The science and global carbon budget for limiting warming to 1.5°C are clear. The time to act is now. With the WorldGBC's Net Zero Carbon Buildings Commitment including both embodied and operational carbon, the organizations, firms and, subnational governments responsible for planning, designing, constructing and developing the global built environment can demonstrate their specific actions that meet the Paris Agreement’s 1.5ºC budget. By showing what is possible, our community will embolden others to do the same."

But there is a real question here about whether this is aggressive enough. The World Green Building Council has been a world leader in bringing embodied carbon upfront and in raising awareness of this issue. This new Net Zero Carbon Buildings Commitment could help change the market. It is not an extreme document, looking to "reduce consumption and eliminate emissions as fast as practicable" and demanding of new buildings that they have "a maximum reduction in embodied carbon and compensation of all residual upfront emissions" without really defining maximum.

It produced this document as a "result of a thorough and extensive 18-month consultation and development process involving input from more than100 focused and dedicated industry experts from both within the Green Building Council community and wider industry stakeholders." So it is perhaps trying not to be too radical.

But times being what they are, I wonder if we don't all have to get radical and be more like the kids at the Architects Climate Action Network who are demanding tough regulation of embodied carbon right now.

every tonne adds to global warming


As the United Nations' Intergovernmental Panel on Climate Change noted in its last report, every ounce or every tonne of CO2 emissions adds to global warming. It's cumulative. As noted in an earlier post on this subject, to have an 83% chance of keeping the temperature rise under 2.7 degrees Fahrenheit (1.5 degrees Celsius) we have a ceiling of 300 metric gigatons. We are running through that real fast.

Vision 2050

World Green Building Council

A Whole Life Carbon Vision for 2050 is admirable. But what matters most is the burp of Upfront Carbon Emissions that we are putting into the atmosphere right now. This is not being addressed or even mentioned; it seems that the industry is resigned to the fact that it is too hard. Or that we are never going to deal with the transport, planning, zoning, parking, or code issues that lock us into our current development patterns. We are not thinking quickly or boldly enough; even the illustration of a whole life carbon vision for 2050 has highways on it.