Stranding risk: when does a building become a problem for the bank?

The short answer

A building „strands“ when its carbon intensity in kilograms per square metre and year rises above the CRREM target pathway, which falls year after year – from that crossing point the asset no longer meets the climate targets and becomes a risk to financing, letting and value. For the owner the decisive lever is not the date in a statute but the point at which the ongoing carbon costs make the retrofit look cheaper than doing nothing.

That point is moving closer because three developments act at the same time: the carbon pricing of fossil heat, the EU buildings directive with its minimum standards, and the taxonomy through which banks and funds steer capital. Read the three together and you can see your own stranding year years in advance.

What does „stranding“ mean for a property?

The Carbon Risk Real Estate Monitor (CRREM) is the standard tool used to date a building's climate risk. Funded under the EU Horizon 2020 programme, it sets out a decarbonisation pathway to 2050 for every country and building type – separately for the 1.5-degree and the 2-degree target. The pathways are expressed in kilograms of CO2 per square metre and year and begin at today's average for the respective building type; from there they fall to near zero by 2050.

A building stays compliant for as long as its actual carbon intensity remains below the pathway. Once the real line crosses the falling pathway, „stranding“ begins: the asset sits above the target value, counts as a „stranded asset“ and starts to accumulate transition risk. What matters is what CRREM measures – operational emissions, that is heating, hot water and electricity, not the embodied carbon of construction and demolition. That is precisely why heat supply decides the stranding year: a fossil heating system keeps the intensity high while the pathway runs away beneath it.

Which rules turn the carbon footprint into a money question?

The CRREM pathway is a voluntary benchmark – it becomes a mandatory programme through three regulatory levers that interlock.

Lever	Core	Relevance for the owner
EPBD / GModG (Directive (EU) 2024/1275)	Minimum energy standards for the worst buildings, implemented nationally	Retrofit and replacement obligations for the weakest assets
EU taxonomy (Reg. (EU) 2020/852)	Definition of „sustainable“ buildings for financial products	Decides whether an asset counts as green and financeable
Carbon price / ETS2	§ 10 BEHG: corridor 55–65 €/t in 2026; ETS2 from 2028 with no cap	Makes every fossil-generated kilowatt-hour more expensive on an ongoing basis

The EU buildings directive EPBD, in its 2024 recast, requires the worst-performing buildings to be retrofitted first; in Germany implementation runs through the Gebäudemodernisierungsgesetz (building modernisation act), which replaces the GEG. The EU taxonomy, in turn, is the reason the topic has moved out of the sustainability department and into the credit department: it determines which property may count in a „green“ fund or loan – and which may not. And the carbon price makes the sum concrete.

Worked example: an apartment block, 2,000 m², gas heating

Assumptions: an unretrofitted apartment block with 2,000 square metres of living space uses around 130 kilowatt-hours of natural gas per square metre and year – that is 260,000 kilowatt-hours. With the emission factor for natural gas of around 0.20 kilograms of CO2 per kilowatt-hour (UBA), that is about 52 tonnes of CO2 a year, or 26 kilograms per square metre.

Carbon price	Basis	Cost/year (52 t)	per m²/year
55 €/t	§ 10 BEHG, lower end of the 2026 corridor	2,860 €	1.43 €
65 €/t	§ 10 BEHG, upper end of the 2026 corridor	3,380 €	1.69 €
100 €/t	illustrative for the free ETS2 phase from 2028	5,200 €	2.60 €

The carbon surcharge on this one building alone thus rises from just under 2,900 euros today towards 5,200 euros a year – before a single kilowatt-hour of gas itself has become more expensive. At 26 kilograms of CO2 per square metre the asset sits well above where Germany's CRREM pathway for residential buildings points in the 2030s; it will therefore foreseeably strand within this decade. Much of the amount can be passed on to tenants through the service-charge statement – but only up to the statutory limit, and the growing gap is ultimately borne by the asset.

Why the bank looks harder than the legislator

The legislator sets deadlines; the bank sets prices. For a fossil-heated property a foreseeable stranding year means a risk premium on the loan, a more cautious figure in the valuation and – if the building misses the taxonomy criteria – exclusion from the cheap financings classed as sustainable. Large portfolio holders report these figures in any case: through the CSRD sustainability reporting duty, which the EU tailored in 2026 in the so-called omnibus procedure to companies with more than 1,000 employees and 450 million euros of turnover, a portfolio's transition risk becomes a reportable number. What is reported gets valued.

For the individual owner this means: the most expensive option is not the retrofit, but waiting until the carbon price, the minimum standard and the financing discount together push the value down.

What owners should do now

1. Determine the asset's carbon intensity – consumption per energy source times emission factor, divided by the floor area. Only this figure makes the stranding year visible.
2. Hold it against the CRREM pathway, for the right building type and the 1.5-degree target; the crossing point is the individual risk date.
3. Project the carbon cost path – with the 2026 corridor as a floor and a free ETS2 phase from 2028 as the risk scenario.
4. Check the financing side: does the asset meet the taxonomy criteria, and how does the bank weigh the transition risk on the next loan?
5. Prioritise the heat supply, because it has the largest lever on operational emissions – and set the retrofit against the carbon and financing costs avoided, not against zero.