You lease it
You pay the bill and need the landlord to agree to anything structural.
You can act on how the building is run, on lighting in most cases, and on anything the lease treats as your own equipment. The roof, the fabric and the incoming supply usually need the landlord, and a solar array almost always does.
You see the saving because you pay the bill, which makes the shorter payback measures worth doing on your own account. For anything structural the case has to be made to whoever owns the building, and the remaining term decides how much of a payback you can justify.
Dilapidations and reinstatement clauses, which decide whether you have to take equipment out again at the end of the term. And the charges on your own bill, which are yours to correct whatever the lease says.
Read the remaining term first and separate the measures you can do alone from the ones that need agreement. Take the landlord a costed case rather than a request, and start with the bill findings, which cost nothing and need nobody.
Every measure we model is set out on what we cover, and how it works runs through the four steps.
Read your own buildings
Add a building and its energy data. Every measure is read against it.