Scope 3 Category 13 Explained: Downstream Leased Assets for Landlords
14 October 2026 · 12 min read · Mian Khubaib Jim
Scope 3 Category 13 runs from 6% to 94% of the footprint at seven UK listed landlords. What sets the number and what the FCA final rules now ask.
Scope 3 Category 13 is where a landlord reports the energy its tenants use in space the landlord owns but does not run. This article answers one question. How large is Scope 3 Category 13 for a UK landlord and what decides its size? The answer comes from the published reports of 12 UK listed real estate companies. Category 13 ranges from 6% to 94% of the reported footprint and the lease decides more of that range than the building does.
Summary of findings
Seven of the 12 companies publish every input needed to calculate the share. Across those seven Category 13 runs from 5.6% of the location based footprint at Workspace to 94.3% at LondonMetric. An all inclusive lease moves tenant energy into the Scope 1 and 2 of the landlord. A full repairing and insuring (FRI) lease leaves nearly all of it in Scope 3. One company leaves the category out of its footprint and gives no reason [1].
Measurement is thin. Three companies state what share of the figure rests on actual data and the range is about 56% to 72%. At Shaftesbury Capital the estimated part of Category 13 equals about a quarter of the entire footprint. Estimates rest on floor area benchmarks and one named benchmark was published in 2008. Under limited assurance the estimation method is reviewed but the data behind it is not tested [2].
The timing is now settled. The Financial Conduct Authority (FCA) published its final rules in PS26/19 on 30 September 2026. Scope 3 reporting under UK Sustainability Reporting Standard S2 (UK SRS S2) applies on a comply or explain basis from accounting periods beginning on or after 1 January 2028 [3].
How much of your own Category 13 is measured? Answer six questions in the free Audit Readiness Check and see where your evidence would hold.
Why this question matters
For most landlords in this sample Category 13 is the largest single number in the footprint. It is 58% at Shaftesbury Capital and 63% at SEGRO and 94% at LondonMetric (Table 1). It is also the number the landlord controls least. Tenants buy the energy and hold the meter data.
Three developments make its quality a reporting question. The FCA final rules bring UK SRS S2 into the annual reports of listed companies for accounting periods beginning on or after 1 January 2027. Scope 3 follows a year later on a comply or explain basis [3]. UK SRS S2 asks a company to disclose which Scope 3 categories it includes (paragraph 29(a)(vi)) and directs it to prioritise direct measurement and primary data and verified data (paragraphs B43 B47 and B53) [4]. GRESB (the real estate sustainability benchmark) has moved emissions from landlord controlled tenant space out of Scope 3 and into Scopes 1 and 2 from its 2026 Standard [5].
The sustainability lead fills the category. The finance director signs a report in which it may be the largest number. Investors compare it between landlords. Each of them needs to know what the number contains.
Definitions
Scope 3 Category 13 (downstream leased assets) covers assets the reporting company owns and leases to others where the emissions are not already in its Scope 1 and 2. Under the Greenhouse Gas (GHG) Protocol its minimum boundary is the Scope 1 and Scope 2 emissions of the lessees from operating those assets [6]. Whether tenant energy lands there depends on the type of lease and the consolidation approach [7].
FRI lease. The tenant repairs and insures the building and in practice runs it. All inclusive lease. Rent includes utilities so the landlord buys the energy.
Data coverage is the share of floor area with some consumption data. Measured share is the part of the reported tonnage calculated from actual data. They are not the same measure.
tCO2e is tonnes of carbon dioxide equivalent. Location based means electricity priced at the average grid emission factor.
Method
The sample is 12 UK listed real estate companies chosen by the writer across offices and retail and logistics and student housing and self storage. For each company the latest annual and sustainability reports were read together with the European Public Real Estate Association (EPRA) data report and basis of reporting and assurance statement where published. Documents were first read on 23 September 2026. Every figure used here was checked again against its source on 5 October 2026.
The share was calculated as Category 13 divided by the sum of Scope 1 and location based Scope 2 and total Scope 3 in the same report. Where a company prints no Scope 3 total the categories were summed or the share is of the items it reports. The estimated part of Category 13 was calculated where a company discloses the share based on actual data.
Findings
Finding 1. Category 13 ranges from 6% to 94% of the reported footprint
Across the seven companies whose reports print every input the category ranges from 5.6% to 94.3% of the location based footprint. Four of the seven sit above 58%.
Table 1. Category 13 as a share of the location based footprint
Company | Period | Category 13 (tCO2e) | Footprint (tCO2e) | Share |
|---|---|---|---|---|
Workspace [8] | Year to 31 March 2026 | 1188 | 21060 | 5.6% |
Derwent London [9] | 2025 | 4482 | 37749 | 11.9% |
Unite [10] | 2024 | 18526 | 116880 | 15.9% |
Shaftesbury Capital [11] | 2025 | 21908 | 37472 | 58.5% |
SEGRO [12] | 2024 | 583195 | 928560 | 62.8% |
Tritax Big Box [13] [14] | 2025 | 64562 | 101201 | 63.8% |
LondonMetric [15] | 2025 | 105114 | 111434 | 94.3% |
Source. Company reports as cited. Footprint is Scope 1 plus location based Scope 2 plus total Scope 3. SEGRO prints no Scope 3 total so its categories were summed. Tritax Big Box prints no Scope 3 total so its share is of the items it reports. Workspace reports the line as customer direct energy within Scope 3.
The other five could not be placed. Big Yellow does not report the category. The latest Landsec and British Land figures sit in spreadsheets that could not be read. Only part of the GPE line was read and no Hammerson figure was found.
Finding 2. The lease model explains most of the spread
The companies at the bottom of the range do not run more efficient buildings. They let space on terms that move tenant energy into their own Scope 1 and 2.
Table 2. Where tenant energy is reported under three lease models
Lease model | Who buys the energy | Where tenant energy is reported | Example in the sample |
|---|---|---|---|
All inclusive lease | Landlord | Landlord Scope 1 and 2 | Workspace. All inclusive leases were 76% of lettings by sales volume in 2025/26 [8]. Unite. Resident energy sits in Scope 1 and 2 [10] |
Tenant buys its own supply | Tenant | Category 13 for tenant demises | Shaftesbury Capital. Category 13 is 58.5% of the footprint [11] |
FRI lease | Tenant | Category 13 for nearly the whole building | LondonMetric. Occupiers control most of the energy use [15] |
Source. Lease arrangements as described by each company in the reports cited.
Boundary choices move the number further. Derwent London reports 4482 tCO2e for its managed portfolio only. It estimates the unmanaged portfolio separately at about 6176 tCO2e [9]. Including that estimate would take the share from 11.9% to 24.3% (10658 divided by 43925). Big Yellow lists Category 13 as outside both its footprint and its science based target boundary and gives no reason [1]. The GHG Protocol requires exclusions to be disclosed and justified [6].
Finding 3. Three companies say how much of the figure is measured
Coverage says how much floor area has some data. Measured share says how much of the tonnage was calculated from it. EPRA asks companies to disclose the proportion of data that is estimated [16]. Three of the 12 do so for Category 13.
Table 3. Measured share of Category 13 and the estimated part
Company | Measured share as disclosed | Estimated part (tCO2e) | Estimated part as share of footprint |
|---|---|---|---|
Landsec [17] | 71% from customer primary data | Not calculated | Not calculated |
LondonMetric [15] | Extrapolated from 72% actual data | About 29400 | About 26% |
Shaftesbury Capital [11] | About 56% from actual data | About 9600 | About 26% |
Source. Company reports as cited. Shaftesbury Capital 21908 × 0.44 = 9640 tCO2e which is 25.7% of 37472. LondonMetric 105114 × 0.28 = 29432 tCO2e which is 26.4% of 111434 if its 72% refers to emissions. The latest Landsec Category 13 figure was not read.
At Shaftesbury Capital about 44% of Category 13 rests on industry benchmarks. That is a quarter of everything the company reports. LondonMetric shows why coverage and measured share differ. Its 2025 figure was extrapolated from 72% actual data but the data used covers 55% of portfolio floor area [15]. Tritax Big Box reports 86% data coverage by floor area for the line [13]. That is a coverage figure and not a measured share.
Finding 4. Estimates rest on benchmarks and one named benchmark dates from 2008
Where tenant data is missing the usual method multiplies floor area by a benchmark energy intensity. The benchmark sets the answer for the estimated part.
Table 4. Benchmarks named for Category 13 estimates
Company | Benchmark named | Vintage stated |
|---|---|---|
GPE [18] | REEB for offices and CIBSE benchmarks for other asset types | Not stated |
Landsec [17] | 2024 REEB from the Better Buildings Partnership | Published June 2025 for 2023/24 data |
British Land [19] | CIBSE TM46 Energy Benchmarks | 2008 |
Shaftesbury Capital [11] | Industry benchmarks not named | Not stated |
Source. Company reporting criteria as cited. REEB is the Real Estate Environmental Benchmarks. CIBSE is the Chartered Institution of Building Services Engineers.
A 2008 benchmark describes the building stock of 2008. Neither the benchmark nor its vintage is visible in the reported figure. It needs naming in the same way as the conversion factor set.
Finding 5. Limited assurance checks the method and not the data behind an estimate
Under International Standard on Assurance Engagements (ISAE) 3410 limited assurance evaluates whether the methods for making estimates are appropriate and applied consistently (paragraph 44L). Testing how the estimate was made and the data on which it is based is a reasonable assurance procedure (paragraph 45R) [2].
The SEGRO 2024 Category 13 figure sits inside an engagement undertaken to a limited level [12]. Tritax Big Box excluded downstream leased assets from its verification scope [14]. Where 28% to 44% of the tonnage rests on estimates (Table 3) an assured figure means the method was reviewed. It does not mean the benchmark inputs were verified. ISAE 3410 is being withdrawn from the effective date of International Standard on Sustainability Assurance (ISSA) 5000 which applies to periods beginning on or after 15 December 2026 [20].
What this means in practice
Five actions before the first UK SRS S2 Scope 3 report
1. State the boundary in one sentence
Say whether the landlord procured and sub metered tenant supply sits in Category 13 or Scope 2. Say whether FRI and unmanaged assets are included and give the reason for any exclusion. Finding 2 shows one boundary choice can double the share.
2. Disclose the measured share and not only coverage
Report what proportion of Category 13 came from meter or invoice or tenant data and what was estimated. EPRA already asks for the estimated proportion [16].
3. Name the benchmark and its vintage
Record which REEB or CIBSE intensity priced each estimated demise in each period. A change of benchmark then becomes a recorded method change.
4. Treat better tenant data as a restatement decision
Keep the reported figure locked. Record the new figure and explain the movement. LondonMetric restated its 2024 Category 13 to 129075 tCO2e in line with its extrapolation method [15].
5. Prepare the explanation as well as the number
Under compete or explain a company that does not disclose must explain why [3]. A lease clause gives permission to ask for tenant data but does not collect it. The green lease clauses and carbon data article covers what has to sit behind the clause.
How Sustainify AI supports Category 13 reporting
Boundary recorded as a rule. Tenant carbon allocation works by lease or area or consumption with time bound rules. Recharge schedules are locked and versioned per period.
A route for tenant data. Unlimited tenant accounts are included in the landlord subscription. Submissions arrive through Scope 3 data collection into a review queue and nothing enters the figure until it is accepted.
Restatements on the record. Closed periods lock under carbon data governance so a move from estimated to measured data becomes a recorded restatement.
Evidence for assurance. Carbon data lineage traces each figure back to the meter reading and the conversion factors and the source file behind it. The platform supports the disclosure. It does not replace an assurance provider.
See your Category 13 boundary and measured share on one governed dataset. Book a demo.
Limitations
The sample is small. Twelve listed companies chosen by the writer do not represent UK landlords as a whole.
The shares are not like for like. Periods run from calendar 2024 to the year to 31 March 2026. SEGRO and Tritax Big Box print no Scope 3 total. Unite labels its Category 13 row per bed although the figure reads as an absolute total and is treated as one here. The shares show a range and not a ranking.
Two calculations rest on readings of company text. The Shaftesbury Capital estimate assumes its 56% refers to tenant emissions. The LondonMetric estimate assumes its 72% refers to emissions and not energy or floor area.
Not stated means not found in the text read. It is not a finding that a company omits something. The Tritax Big Box 2025 figure may be updated by the company. The ISAE 3410 wording was checked against a reproduction of the text issued by the International Auditing and Assurance Standards Board.
What not to conclude. A high share does not mean a poorly performing landlord. A low share does not mean low tenant emissions. Estimated figures are not wrong. The GHG Protocol provides for estimation and allows exclusions that are disclosed and justified [6].
References
[1]Big Yellow Group PLC. Basis of Reporting 2025/26. Page 3. Accessed 5 October 2026.
[2]International Auditing and Assurance Standards Board. ISAE 3410 Assurance Engagements on Greenhouse Gas Statements. 2013 Handbook edition. Paragraphs 44L and 45R. Accessed 5 October 2026.
[3]Financial Conduct Authority. PS26/19 Aligning listed issuers sustainability disclosures with international standards. 30 September 2026. Accessed 5 October 2026.
[4]Department for Business and Trade. UK Sustainability Reporting Standard S2 Climate related Disclosures. 25 February 2026. Paragraph 29(a)(vi) and paragraphs B43 B47 and B53. Accessed 5 October 2026.
[5]GRESB. Realigning Scope classification for landlord controlled tenant space emissions. 12 November 2025. Accessed 5 October 2026.
[6]World Resources Institute and World Business Council for Sustainable Development. Corporate Value Chain (Scope 3) Accounting and Reporting Standard. 2011. Table 5.4 and Chapter 6. Accessed 5 October 2026.
[7]GHG Protocol. Technical Guidance for Calculating Scope 3 Emissions Category 13 Downstream Leased Assets. 2013. Page 128. Accessed 5 October 2026.
[8]Workspace Group plc. 2026 Sustainability Report. Annual Report and Accounts 2026. Pages 81 to 85. Accessed 5 October 2026.
[9]Derwent London plc. Responsibility Report 2025. Page 11. Accessed 5 October 2026.
[10]The Unite Group PLC. Sustainability Report 2024. Pages 17 and 27 to 28. Accessed 5 October 2026.
[11]Shaftesbury Capital PLC. 2025 EPRA Sustainability Data Report. April 2026. Pages 6 25 and 33. Accessed 5 October 2026.
[12]SLR Consulting Limited. ISAE 3000 Assurance Statement SEGRO plc 1 January 2024 to 31 December 2024. 4 February 2025. Accessed 5 October 2026.
[13]Tritax Big Box REIT plc. EPRA Sustainability Report 2025. Page 17. Accessed 5 October 2026.
[14]Tritax Big Box REIT plc. ESG Data Sheet and GHG Verification Statement 2025. Pages 2 to 3. Accessed 5 October 2026.
[15]LondonMetric Property plc. Responsible Business and ESG Report 2026. Pages 3 25 and 26. Accessed 5 October 2026.
[16]European Public Real Estate Association. EPRA Sustainability Best Practices Recommendations Guidelines Fourth Edition. April 2024. Section 7.3 on page 9. Accessed 5 October 2026.
[17]Land Securities Group plc. Sustainability Additional Disclosures 2026. Page 25. Accessed 5 October 2026.
[18]Great Portland Estates plc. Basis of Reporting 2026. Page 12. Accessed 5 October 2026.
[19]The British Land Company PLC. Reporting Criteria and Independent Assurance 2026. Page 7. Accessed 5 October 2026.
[20]International Auditing and Assurance Standards Board. IAASB Announces Withdrawal of ISAE 3410 Assurance Engagements on Greenhouse Gas Statements. May 2025. Accessed 5 October 2026.
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Frequently Asked Questions
What is Scope 3 Category 13?
Scope 3 Category 13 covers downstream leased assets. For a landlord it is the energy related emissions of tenants in space the landlord owns and leases out where those emissions are not already in landlord Scope 1 and 2 [6].
Is tenant energy Scope 2 or Scope 3 for a landlord?
It depends on the lease and the consolidation approach [7]. Energy a tenant buys for space it controls sits in Category 13. Under an all inclusive lease the landlord buys the energy so it moves into landlord Scope 2. Tenant carbon allocation records which rule applied to each demise.
When must listed UK landlords report Scope 3 Category 13?
Under FCA PS26/19 UK SRS S2 applies to accounting periods beginning on or after 1 January 2027. Scope 3 has one year of relief so comply or explain applies from accounting periods beginning on or after 1 January 2028 [3]. Streamlined Energy and Carbon Reporting (SECR) does not require Scope 3.
Why is Category 13 so different from one landlord to another?
Mostly because of the lease. It runs from 5.6% of the footprint at Workspace where most new leases are all inclusive to 94.3% at LondonMetric where occupiers control most of the energy use [8] [15].
How do landlords estimate Category 13 when tenants share no data?
They multiply floor area by a benchmark intensity such as REEB or CIBSE figures or extrapolate from tenants who do share data [18] [15]. The article on estimated versus measured data explains how that split affects ESG scores.
What is the difference between data coverage and measured share?
Coverage is the share of floor area with some data. Measured share is the part of the tonnage calculated from actual data. LondonMetric extrapolated from 72% actual data while the data used covers 55% of floor area [15].
Why does Category 13 change when tenant data improves?
Metered consumption replaces a benchmark estimate and the two rarely match. LondonMetric restated its 2024 figure to 129075 tCO2e in line with its extrapolation method [15]. Under carbon data governance the earlier figure stays locked and the change is recorded.
Can a landlord leave Category 13 out of its footprint?
The GHG Protocol allows exclusions only if they are disclosed and justified [6]. Under the FCA final rules a listed company that does not disclose Scope 3 must explain why [3].
How does GRESB treat landlord controlled tenant space?
From its 2026 Standard GRESB moves emissions from landlord controlled tenant space out of Scope 3 and into Scopes 1 and 2. GRESB states that only around 9% of assets include floor area of that kind [5].
Does limited assurance check the data behind a Category 13 estimate?
No. Limited assurance under ISAE 3410 evaluates whether the estimation method is appropriate and consistently applied. Testing the underlying data is a reasonable assurance procedure [2]. Carbon assurance readiness starts with knowing which figures are estimated.