The GHG Protocol is about to make your Scope 3 estimates visible.

For the first time since 2011, the rules on value chain emissions reporting are being rewritten. But don’t panic just yet – you don’t need to do anything right now. 

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The Greenhouse Gas Protocol has been the backbone of corporate emissions reporting for over a decade. Its Scope 3 Standard, published in 2011, defines how companies measure and report their value chain emissions. Most sustainability frameworks, like CSRD, SBTi, and CDP, are built on top of it.

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On 31 March 2026, GHG Protocol published its Phase 1 Progress Update: the first meaningful output of a full revision process. A 65-member technical working group, drawing on expertise from more than 20 countries, has held 42 sessions since September 2024 to get here (and you thought it took a lot of meetings to get that thing you were working on done). 

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Despite all that, it's still a working draft, not a final standard. A public consultation is still to come, and a final revised standard isn't expected until late 2027. And that’s why you don’t need to drop what you’re doing and start panicking right now. 

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So what's actually changing?

The changes essentially tighten the belt. A lot more documentation is required, verification comes into force, and estimates just won’t cut it anymore. And, as said, while you don’t need to change anything today, the direction of travel is clear. For real estate companies, a few of the proposed changes are worth paying close attention to – if you’re reporting according to the GHG Protocol, of course. 

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Your estimates are going to show

As it is today, companies report a total figure per Scope 3 category, with a written description of the methodology. What's not visible in the numbers themselves is how much of that figure is based on real activity data, and how much is a spend-based estimate.

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The proposed revision would change that. Each category would need to be disaggregated by data type: specific activity data on one side, spend-based or economic proxy estimates on the other.

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In practice, this means the quality of your Scope 3 data becomes directly visible to clients, to investors, and to the frameworks that use Scope 3 data to assess you. A total figure that looks complete stops being good enough if most of it is labelled "estimate."

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You'll need to disclose whether you've been verified

At the moment, there's no requirement to say whether your Scope 3 inventory has been independently verified. The proposed revision introduces three disclosure labels: Fully verified, Partially verified, or Not verified. If you verify, you say so. If you don't, that's visible too.

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The 95% floor

Under the current standard, companies can exclude Scope 3 categories by describing them as not significant without necessarily running the numbers to check. Not anymore. The proposed revision introduces a hard minimum: at least 95% of a company’s Scope 3 emissions must be covered. Exclusions will need to be justified and documented, not simply declared.

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Category 15 now applies to everyone

Category 15 covers emissions associated with investments – what's often called financed emissions. In practice, it's been treated as relevant mainly to banks and asset managers. The proposed revision makes the scope explicit: any company with investments is in. That means real estate companies with equity stakes, joint ventures, project finance, or minority holdings will need to account for them.

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What does this mean for real estate?

Real estate companies aren't in the spotlight of this revision. Phase 2 will cover category-specific updates, where the sector's most material categories (construction, tenant energy use, downstream leased assets) will probably pop up. However, three of the Phase 1 changes land smack bang on real estate portfolios.

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The 95% coverage floor affects any company that has been excluding categories without measuring them. The data quality disaggregation affects any company still relying on energy estimates rather than actual meter data (we all know that's more common than most sustainability teams would like to admit). And Category 15 affects the asset managers and fund structures that have treated financed emissions as someone else's problem.

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The red thread running through all three changes is the same: the gap between what you report and what you actually know is about to become auditable. It might sting for some, but hopefully not too many. 

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You don't need to act today. But here's what's worth doing.

This is not a compliance deadline. The standard hasn't changed. But if you're working to SBTi targets, the timeline is tighter than it looks. The new SBTi Corporate Net-Zero Standard is being written to reference the revised GHG Protocol, and every company with a validated target will need to adopt the updated methodology at its five-year review. 

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Three things worth doing now:

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Audit your coverage. Which Scope 3 categories are you currently excluding, and on what basis? If the answer is "we thought they weren’t significant," that's probably worth revisiting before the 95% rule becomes binding.

Look at your data quality. What proportion of your Scope 3 figures are built on actual energy data versus estimates? The revision rewards companies that can show a high primary data share. If yours is low, that's a gap worth closing before it becomes a disclosure requirement.

Map your Category 15 exposure. If your portfolio includes joint ventures, minority stakes, or project finance structures, now is a good time to understand what that means for your emissions boundary.

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The 2011 standard gave companies a lot of flexibility, but that flexibility is narrowing. The revised standard is moving toward tighter boundaries, clearer data quality requirements, and more explicit disclosure. And this isn’t a bad thing; it's the standard catching up with what good reporting already looks like.

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If you’re still guilty of using estimates, get in touch. We know a place that pulls your energy data directly from the source. 

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