I lease a building and don't know my energy consumption, what do I fill in

No own meter is not a barrier to scope 2

Without your own meter, you enter the energy consumption based on the building manager or landlord, not based on an estimate from your head. Most landlords of commercial properties with shared connections can provide an allocation key — often per square metre of floor space — which distributes the total consumption of the building to the tenants. Request that allocation key and keep the underlying invoice or settlement from the landlord as proof. That is the same route as for what is the total energy consumption per year: a traceable figure, not an educated guess.

For scope 2 according to the GHG Protocol, it does not matter whether you physically read the meter yourself or whether the landlord does — what determines it is which energy can be attributed to your activities. If you have no substantiation whatsoever, not even an allocation key, then it is better to enter nothing than an estimated figure without a source: an empty cell with an explanation ("no submeter, allocation key requested from landlord") is more defensible than a made-up kWh figure. This often goes hand in hand with the question of the share of renewable energy: that share also follows from the energy contract of the landlord, not from your own assessment.

Where this connects to: VSME module and GHG classification

The VSME basic module of EFRAG requests energy consumption as a quantitative figure without prescribing the measurement method; an allocation of building consumption based on floor area is thus compatible with it, provided it is traceable. The GHG Protocol places purchased energy in scope 2, regardless of who manages the meter — the reporting obligation lies with the user of the energy, not with the meter holder. If you are in doubt about how this relates to scope 1 and 3 in the same questionnaire, then the explanation of scope 1, 2 and 3 combined.